Somatic spinal cord reflexes And Spinal cord lesions & Spinal shock
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Rehabilitation Engineering Laboratory Toronto Rehab, Lyndhurst Centre 520 Sutherland Dr. Toronto, Ontario Canada M4G 3V9 www.toronto-fes.ca Rehabilitation Engineering Laboratory - 2012
Transcript of ring Laboratorytoronto-fes.ca/brochures/REL_Brochure2013.pdf · We develop advanced technologies...
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Toronto Rehab, Lyndhurst Centre 520 Sutherland Dr.
Toronto, Ontario Canada M4G 3V9
www.toronto-fes.ca
Rehabilitation Engineering Laboratory - 2012
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
About the Rehabilitation Engineering Lab
History
The Rehabilitation Engineering Laboratory was established in 2001 at the Lyndhurst Centre of Toronto Rehab. In 2006 and in 2009, the laboratory underwent two major renovations, quadrupling the amount of space and equipment available for personnel and experiments.
What We Do
We develop advanced technologies for spinal cord injury (SCI) and stroke rehabilitation. These include brain/machine interfaces, assessment tools for determining an individual’s level of function, and rehabilitation techniques for restoring walking, sitting, standing, reaching, and grasping ability. We also design neuroprosthetic systems to assist individuals with tasks such as walking, reaching, grasping, and balance during standing and sitting.
Most of our work is based on functional electrical stimulation (FES), which uses electricity to cause muscles to contract. FES can be used to provide movement to paralyzed muscles to re-train weak muscles and the injured central nervous system.
Accomplishments – 2010-2012
Completed a number of randomized control trials with stroke and SCI individuals involving FES therapies
Developed advanced communication and stimulation technologies for neuroimplants
Provided FES therapy to more than 50 individuals with SCI or stroke
Published 41 peer-reviewed journal papers
Obtained more than $1.1M in direct funding and collaborated on grants which total funding exceeded $0.6M
Trained 8 postdoctoral fellows, and 22 graduate students in SCI and stroke research, who obtained an additional $1M in funding
Want to Get Involved?
We’re always looking for participant for our studies, volunteers to help us with the experiments, and students and research collaborators. If you would like to join us, please feel free to contact us at 416-597-3422, Ext. 6206.
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Research at the Rehabilitation Engineering Laboratory
Neuroprosthesis for Reaching and Grasping
Our reaching and grasping neuroprosthesis is designed for individuals who cannot reach and/or grasp voluntarily. These individuals are able to use the system to pick up and manipulate objects, significantly improving their independence in activities of daily living. People who have SCI at C3-C7 level or severe stroke have used this system as a rehabilitation tool to assist in retraining voluntary reaching and grasping. Neuroprosthesis for Walking
The purpose of the neuroprosthesis for walking program is to demonstrate the long-term benefits of FES therapy on walking function in patients with incomplete SCI and stroke. Our studies showed a significant improvement in walking speed and/or a reduction in the use of assistive devices for walking after using the neuroprosthesis. In this application the neuroprosthesis for walking is used as a short-term intervention for improving voluntary walking function.
Neuroprosthesis for Sitting
Trunk instability is a major problem for many people with SCI, affecting their independence and ability to perform activities of daily living. The long-term objective of this project is to produce a new device that will improve sitting stability by stimulating paralyzed trunk muscles using FES. This sitting neuroprosthesis will improve the ability of people with SCI to perform such tasks as reaching and wheeling. We are currently studying the mechanisms of balance in the trunk and the consequences of muscle paralysis on these mechanisms. This analysis will form the basis for developing the FES system for balance during sitting.
Neuroprosthesis for Standing
The neuroprosthesis for standing and balancing is a device that will allow some neurologic patients to stand up, perform stable “hands-free” standing, and sit down again. At least two applications of this technology are envisioned: 1) this device will be used as an independent system to allow complete SCI patients to stand; and 2) to retrain standing function and balance control in incomplete SCI, stroke and elderly patients through active, repetitive, balance training sessions. Besides the obvious functional benefits, this neuroprosthesis would also help maintain bone density and prevent pressure sores by allowing people to stand for extended periods of time.
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Human-Machine Interfaces
Understanding the relationship between an assistive device and its user is a fundamental step towards designing better systems. The human-machine interface project focuses on developing new communication strategies and methodologies to allow users to have more natural control over an assistive device. One aspect of this work is our research into brain-machine interfacing, which investigates the relationship between intended arm movement and electroencephalogram (EEG) or electrocorticographic (ECoG) signals from the motor cortex of the brain.
Novel Neuroprosthesis
People with spinal cord injury have impaired movements of their arms and/or legs, due to paralyzed muscles. Rehabilitation using electrical muscle stimulation is very advantageous for this patient population. However, one aspect that often limits the use of electrical stimulation is the rapid onset of muscle fatigue. One can potentially explain the muscle fatigue following electrical stimulation by the fact that electrical stimulation contracts muscle fibers simultaneously and that electrical stimulation is unable to contract all the fibers within the muscle. In the current project, we propose a new stimulation method that would activate most of the muscle fibers in a regulated cyclic pattern.
Equipment
The Rehabilitation Engineering Laboratory has a variety of research equipment including:
Compex II stimulators
Body weight support treadmills
Force plates
Polhemus motion capture system
Optotrack dual camera motion capture systems
6-camera Raptor Motion Analysis system
ARMEO and ReJouce systems for upper limb rehabilitation
ERIGO tilt table with motorized leg movement
Electromagnetically shielded room for EMG and EEG measurements
Vibration platforms
REL-PAPPS perturbation system
Biodex System 3
Various EMG and EEG measurement systems
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Our People
Principal Investigators
Dr. Milos R. Popovic (biomedical engineering), Head of the Laboratory,
Toronto Rehab Chair in Spinal Cord Injury Research, Senior Scientist, and
Professor
Dr. Cesar Marquez-Chin (biomedical engineering), Research Scientist
Dr. Kei Masani (exercise physiology), Research Scientist and Assistant
Professor
Dr. Mary Nagai (surgery), Research Scientist and Assistant Professor
Postdoctoral Fellows
Dr. Elias Daniel Guestrin (biomedical engineering), Postdoctoral Fellow
Dr. Santa Concepción Huerta Olivares (electronics), Postdoctoral Fellow
Dr. Reza Javaheri (electronics), Postdoctoral Fellow
Dr. Masae Miyatani (exercise physiology), Postdoctoral Fellow
Dr. Aravind Kumar Namasivayam (speech/language), Postdoctoral Fellow
Dr. Hossein Rouhani (biomedical engineering), Postdoctoral Fellow
Dr. Dimitry Sayenko (space medicine), Postdoctoral Fellow
Dr. Jose Zariffa (biomedical engineering), Postdoctoral Fellow
Graduate Students
Davide Agnello, MASc student
Kathryn Atwell, MASc student
Sara Ayatollahzadeh, MEng student
Rob Babona-Pilipos, PhD student
Martha Gabriela Garcia-Garcia, MASc student
Diane Kostka, MHSc student
Meredith Kuipers, MSc student
Cheryl Lynch, PhD student
Andresa R. Marinho, PhD student
Steve McGie, PhD student
Bahar Memarian, MASc student
Matija Milosevic, PhD student
Michael Same, MASc student
Egor Sanin, MASc student
Miyuki Tsukimoto, MASc student
Albert Vette, PhD student
Noel Wu, MASc student
Takashi Yoshida, PhD student
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Our People
International Research Placements
Stefanie Buley - University of Applied Science Senftenberg, Germany
Ubaldo Garcia - Universidad Iberoamericana, Mexico
Marisol Martinez - Universidad Iberoamericana, Mexico
Karen Rodriguez - Universidad Iberoamericana, Mexico
Catalina Villa Saenz - School of Engineering of Antioquia, Columbia
Support Staff
Shaghayegh Bagher, Research Engineer
Zina Bezruk, Administrative Assistant
Betty Chan, Grants & Accounts Coordinator
Naaz Desai, REL Manager, Research Coordinator and Physiotherapist
Jennifer Holmes, Occupational Therapist
Anne Hu, Physiotherapist
Lorna Lo, Occupational Therapist
Esther Oostdyk, Secretary
Abdulazim Rashidi, Research Engineer
Egor Sanin, Research Engineer
Dr. Vera Zivanovic, Research Coordinator
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Awards and Distinctions
Robert Babona-Pilipos
2010 Scientific Day 2010 Best “Lightning Round” Presentation
Institute of Biomaterials and Biomedical Engineering, University of Toronto
2011 St. George’s Society Graduate Scholarship
University of Toronto
2011 CREATE – CARE Graduate Scholarship
Natural Sciences and Engineering Research Council of Canada
2011 Best Paper Award 2010-2011 in the category “Biomaterials, Tissue Engineering and Regenerative Medicine
Institute of Biomaterials and Biomedical Engineering, University of Toronto
Zachary Dulberg
2011 Summer Student Scholarship
Natural Sciences and Engineering Research Council of Canada
Martha Gabriela Garcia-Garcia
2011 Graduate Scholarship Ontario Council on Graduate Studies of Canada and the National Council of Science and Technology of the United Mexican States
2012 Connaught Grant for Foreign Students
University of Toronto
Vasily Grigorovsky
2011 Finalist of the Centennial Thesis Award
Engineering Sciences, University of Toronto
Navid Javadi
2011 Summer Student Scholarship
Natural Sciences and Engineering Research Council of Canada
Meredith Kuipers
2010 Ontario Graduate Scholarships in Science and Technology
University of Toronto
2010 Student Travel Award, Young Investigators’ Forum
Institute of Circulatory and Respiratory Health, Canadian Institute of Health Research
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Awards and Distinctions
Cheryl Lynch
2010 Best Student Paper Award – Third Place
15th International Functional Electrical Stimulation Society Conference
2011 Neural Engineering and Therapeutics Team Excellence Award
Toronto Rehabilitation Institute
Steve McGie
2010 Barbara and Frank Milligan Graduate Fellowship
University of Toronto
2011 Ontario Graduate Scholarship in Science and Technology (declined)
University of Toronto
2011 OSOTF: Graduate Student Studentship
Toronto Rehabilitation Institute
2012 OSOTF: Graduate Student Studentship
Toronto Rehabilitation Institute
Matija Milosevic
2010 Graduate Research Excellence Award (GREA)
Electrical and Computer Engineering, Ryerson University
2011 CREATE-Care Graduate Scholarship
Natural Sciences and Engineering Research Council of Canada
2012 School of Graduate Studies Conference Grant
University of Toronto
Dr. Masae Miyatani
2011 Postdoctoral Fellowship The Craig H. Neilsen Foundation Dr. Milos R. Popovic
2011 Elected Fellow American Institute for Medical and Biological Engineering, Washington, USA
2012 TiEQuest Business Venture Competition: 1st Prize
TiEQuest, Toronto, Canada
2012 TiEQuest Business Venture Competition: Best Intellectual Property Award
TiEQuest, Toronto, Canada
2012 Innovation Award Connaught Committee, University of Toronto
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Awards and Distinctions
Saswat Pradhan
2011 Summer Student Scholarship
Natural Sciences and Engineering Research Council of Canada
Dr. Hossein Rouhani
2012 Postdoctoral Fellowship Swiss National Science Foundation
Dr. Dimitry Sayenko
2010 Best Poster Award 9th Annual Charles Tator-Barbara Turnbull Lectureship on Spinal Cord Injury, Toronto, Canada
Noel Wu
2010 Graduate Fellowship Barbara and Frank Milligan Graduate Fellowship, University of Toronto
Dr. Albert Vette
2010 CIHR Strategic Research Training Post-Doctoral Fellowship in Health Care, Technology & Place
Canadian Institute of Health Research
2010 MITACS Industrial Fellowship Award
MITACS
2010 “Focus on Stroke 9” Postdoctoral Fellowship
Heart and Stroke Foundation of Canada, Canadian Institute of Health Research and the Canadian Stroke Network
2010 Best Paper Award 2009-2010 - category “Neural, Sensory System and Rehabilitation Engineering
Institute of Biomaterials and Biomedical Engineering, University of Toronto
2010 Best Student Paper Award – Third Place
4th National Spinal Cord Injury Conference, Niagara Falls.
Takashi Yoshida
2010 Institute for Technology Thesis Award
Institute of Biomaterials and Biomedical Engineering, University of Toronto
2010 CREATE – CARE Graduate Scholarship
Natural Sciences and Engineering Research Council of Canada
2012 Student Scholarship Toronto Rehabilitation Institute, the Faculty of Medicine, University of Toronto
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Awards and Distinctions
Takashi Yoshida
2012
Award for Student Poster in Clinical Science
Aftab Patla Research Innovation Award, 20th International Society for Gait and Posture Conference, Trondheim, Norway
2012 Best Paper Award 2011-2012 – category “Neural, Sensory System and Rehabilitation Engineering
Institute of Biomaterials and Biomedical Engineering, University of Toronto
Dr. Jose Zariffa
2011 Clinical Research Fellowship
Canadian Paraplegic Association Ontario
2011 Winner of the Gordon Hiebert Prize for Best Postdoctoral Fellow Poster
ICORD Annual Research Meeting
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Recent Research Posters
Neuroprosthesis for Grasping
1. Brain-Controlled Functional Electrical Stimulation for Retraining of Grasp Function
2. FES Therapy for grasping in incomplete SCI: Randomized Control Trial 3. Toronto Rehabilitation Institute’s Hand Function Test For Gross Motor
Assessment
Neuroprosthesis for Sitting
4. Respiratory Function Increases with Trunk Muscle Stimulation Among Individuals with Spinal Cord Injury
5. Visualization of Trunk Muscle Synergies during Sitting Perburbations 6. Does Functional Electrical Stimulation of Trunk Muscles Alter
Respiration in Spinal Cord Injury? 7. Linking FES-assisted sitting stability and breathing in spinal cord injury 8. A Complete, Universal, and Verifiable Set of Upper Body Segment
Parameters for Three-Dimensional Dynamic Modeling 9. Self-Organizing Map for Data Mining of EMG Trunk Muscle Signals
During Sitting 10. Quantifying Multi-directional Trunk Stiffness During Sitting with and
without Functional Electrical Stimulation
Neuroprosthesis for Standing
11. Center of Pressure Velocity Captures Body Acceleration Rather Than Body Velocity During Quiet Standing
12. Decomposing the Ankle during Quiet Standing into Active and Passive Components using EMG
13. Controlling Balance during Quiet Standing via Co-Contraction in the Elderly May Not Be Advantageous
Cardiovascular
14. Decrease in Venous Return due to Postural Change is Mitigated by Functional Electrical Stimulation for People with Spinal Cord Injury
15. The Associations Between Aerobic Capacity and Arterial Stiffness in People with Chronic Spinal Cord Injury
Human-Machine Interfaces
16. Typing with Eye-Gaze and Tooth-Clicks 17. EMG-onset Detection using Change-point Analysis
Rehabilitation Engineering Laboratory – 2012
Contact us:
Lyndhurst Centre Toronto Rehab 520 Sutherland Dr. Toronto, ON M4G 3V9 Canada
416-597-3422 x 6206
www.toronto-fes.ca
Brain Machine Interface
18. A Novel Assistive Device for Cursor Control 19. Estimation of Arm Kinematics From ElectroCorticoGraphic Recording 20. Using Electrocorticographic Recordings to Estimate Upper Limb
Kinematics
Whole Body Vibration
21. Acute Effects of Passive Standing and Whole Body Vibration on Arterial Stiffness
22. Serum 25(OH)D Levels and Tibia Volumetric Bone Mineral Density (vBMD) in Chronic Spinal Cord Injury (SCI)
23. Usability of the Juvent™ and WAVE® Whole Body Vibration Plates for Men with and without Spinal Cord Injury
24. Whole Body Vibration and EMG Activation: Effects of Vibration Frequency, Amplitude and Posture
25. Development of a Sham Condition for Future Whole Body Vibration Intervention Trials
Other Projects
26. Bilateral Soleus H-Reflexes in Humans During Sitting and Passive Standing: Variability and Correlation.
27. Effects of Voluntary Exercise, Functional Electrical Stimulation and Vibration on Corticomuscular Coherence
28. Response of Individual Muscles to Neuromuscular Electrical Stimulation Training of Knee Extensors
29. Novel Methodology to Reduce Muscle Fatigue during Functional Electrical Stimulation using Spatially Distributed Sequential Stimulation
30. A Multi-Channel Current-Regulated Output Stage for an Electrical Stimulator
31. Including Non-Ideal Behaviour in FES Simulations 32. Including Non-Ideal Behaviour in Simulations of FES 33. Improved Fatigue Resistance in Leg Muscles during Spatially
Distributed Sequential Stimulation
Canadian Institutes of Health ResearchInstituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of CanadaConseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health and Long Term Care
Partners:Rehabilitation Engineering LaboratoryInstitute of Biomaterials and Biomedical Engineering, University of TorontoToronto Rehabilitation InstituteContact: [email protected] (or your email address)www.toronto-fes.ca
Brain-Controlled Functional Electrical Stimulation for Retraining of Grasp Function
Steven McGie1, Milos Popovic1,21University of Toronto, IBBME; 2Toronto Rehab Institute
• Functional electrical stimulation (FES) can facilitate rehabilitation following a spinal cord injury (SCI).• Brain-machine interfaces (BMI) read neural signals, and use them to control external devices.• BMI can be used to control an FES stimulator.• This can restore innervation to otherwise paralyzed limbs.
Introduction
• System completed and tested on able-bodied volunteers.• Recruitment for individuals with high-level SCI opened; no participants at the time of writing.• System needed modification to account for stimulation artefact.
Discussion
Conclusions• The feasibility of BMI-controlled FES has been proven.• The hypothesis (that BMI-controlled FES can provide greater rehabilitative effect than regular FES) remains to be tested; contingent on recruitment.
Fig. 1: Schematic of how BMI-controlled FES can circumventa spinal lesion. The red line indicates alternate paths bywhich a motor command can reach the target muscles.
Normal SCI + BMI + FES
Fig. 2: Mechanisms of Hebbian plasticity. Ca2+ influx through NMDA channels causes synaptic strengthening. BMI-
controlled FES may establish this contingency by ensuring consistent pairing of activity on both sides of the synapse.
• Neural recordings are non-invasively obtained from hand-related areas of primary motor cortex using electroencephalography (EEG).• EEG recordings are analyzed in real-time to determine the bandpower in a specific frequency band.• Sustained changes in bandpower across a threshold send a signal to switch FES from “Rest” to “Flexion” mode.• Switch from “Flexion” to “Extension” is done via push-button, since artefacts from stimulation contaminate the EEG signal.• Switch from “Extension” to “Flexion” occurs after 3.5 s.• Extensive calibration routines are used to determine ideal parameter values.
• Based on a short session in which the user is cued to either attempt a movement or to relax.•The system then finds parameters which allow for ideal discrimination between the two tasks.
Methods - System
Fig. 3: Timeline of each subject's participation.
NO PLASTICITY PLASTICITY
Hypothesis• BMI-controlled FES may have a greater rehabilitative effect than regular FES, by following classic “Hebbian” rules of neuroplasticity.• Synapses are strengthened when both sides are activated simultaneously.•BMI-controlled FES may ensure consistent pairing of activity in both sides of the spinal synapse.
• Descending commands control the BMI.• Antidromic firing caused in the periphery by FES goes back up to the synapse.
Fig. 4: Sample EEG recording showing periods with and without contamination from the stimulation artefact.
Artefact Normal Recording ArtefactRecovery
• Participants will be individuals with incomplete C4-C7 SCI• The intervention will consist of 40 sessions (2 months) of using BMI- controlled FES to perform functional movements.• Outcome measures will include self-report measures of functional independence, functional assessments, and physiological assessments.
Methods - Treatment
Part
ners
:
Can
adia
n In
stitu
tes
of H
ealth
Res
earc
h In
stitu
ts d
e re
cher
e en
san
té d
u C
anad
a N
atur
al S
cien
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and
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neer
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earc
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ounc
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Can
ada
Con
seil
de re
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ches
en
scie
nces
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urel
les
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n gé
nie
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anad
a
Min
istr
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lth
and
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m C
are
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exib
le a
nd p
rogr
amm
able
FE
S s
yste
m.
•R
epet
itive
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ly tr
eatm
ents
. •
FES
in c
ombi
natio
n w
ith O
T.
•FI
M s
elf c
are
sub-
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e: 2
0 po
ints
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ovem
ent
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erap
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OT)
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•S
CIM
sel
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e su
b-sc
ore:
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ts im
prov
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t (F
ES
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I-HFT
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re fo
r man
ipul
atio
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so a
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ngin
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abor
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Inst
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onta
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ilos.p
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ww
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FES
Ther
apy
for g
rasp
ing
in in
com
plet
e SC
I: R
ando
miz
ed C
ontr
ol T
rial
MR
Pop
ovic
1,2 ,
N K
apad
ia2 ,
V Z
ivan
ovic
2 , JC
Fur
lan2
, BC
Cra
ven2
,3, K
Nak
azaw
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nd C
McG
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1 To
ront
o R
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tion
Inst
itute
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BM
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Uni
vers
ity o
f Tor
onto
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epar
tmen
ts o
f Med
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e an
d H
ealth
Pol
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Man
agem
ent a
nd E
valu
atio
n - U
nive
rsity
of T
oron
to,
4 Dep
artm
ent o
f Life
Sci
ence
s, G
radu
ate
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ool o
f Arts
and
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ence
s, U
nive
rsity
of T
okyo
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an
•Th
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abou
t 350
,000
SC
I sur
vivo
rs in
US
and
Can
ada,
and
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hem
are
Q
uadr
iple
gics
. •
50%
of t
he Q
uadr
iple
gics
rank
ed r
etur
n
of
arm
han
d fu
nctio
n as
thei
r hig
hest
prio
rity.
Met
hods
•
Ran
dom
ized
con
trol t
rial
•C
ontro
l: n=
12 a
nd F
ES
ther
apy:
n=9
•
Bot
h gr
oups
rece
ived
40
sess
ions
of
ther
apy
•C
ontro
l gro
up re
ceiv
ed 2
hou
rs o
f co
nven
tiona
l occ
upat
iona
l the
rapy
(CO
T)
and
inte
rven
tion
grou
p re
ceiv
ed 1
hou
r of
CO
T pl
us 1
hou
r of F
ES
ther
apy.
•
Prim
ary
outc
ome
mea
sure
was
FIM
Sel
f C
are
Sub
sco
re a
nd s
econ
dary
out
com
e m
easu
res
wer
e S
CIM
Sel
f Car
e S
ub s
core
an
d TR
I-HFT
.
Subj
ect D
emog
raph
ics
Intr
oduc
tion
R
esul
ts
FES
Ther
apy
Part
icip
ant
Ref
eren
ces
Feat
ure
Con
trol
G
roup
In
terv
entio
n G
roup
p
valu
e
Age
(yea
rs)
M
ean
age
± S
EM
44
.75
± 4.
72
43.2
± 5
.45
0.89
6 M
edia
n ag
e 51
.5
50
A
ge ra
nge
20 to
65
18 to
66
Se
x (n
)
Mal
es
9 8
1 Fe
mal
es
3 2
C
ause
of S
CI (
n)
M
otor
veh
icle
ac
cide
nt
7 2
0.00
9
Fall
2 8
O
ther
cau
ses
3 0
Se
verit
y of
SC
I (n)
AIS
B
4 4
0.51
7 A
IS C
8
5
AIS
D
0 1
Le
vel o
f SC
I (n)
C3
0 1
0.07
1 C
4 7
3
C5
4 1
C
6 1
5
Tim
e si
nce
SCI
(day
s)
Mea
n tim
e ±
SE
M
58.3
3 ±
6.55
69
.9 ±
14.
11
0.97
4 M
edia
n tim
e 63
.5
50
A
ge ti
me
22 to
102
33
to 1
64
Rec
omm
enda
tions
•P
opov
ic, K
apad
ia, Z
ivan
ovic
, Fur
lan,
Cra
ven,
and
McG
illiv
ray,
N
euro
reha
bilit
atio
n an
d N
eura
l Rep
air,
vol.
25, N
o. 5
, pp:
43
3-44
2, 2
011.
•
Pop
ovic
, Thr
ashe
r , A
dam
s, T
akes
, Ziv
anov
ic, a
nd T
onac
k,
Spi
nal C
ord,
vol
. 44,
No.
3, p
p. 1
43-1
51, 2
006.
•
Kap
adia
, Ziv
anov
ic, F
urla
n, C
rave
n, M
cGill
ivra
y, a
nd P
opov
ic,
Arti
ficia
l Org
ans,
vol
. 35,
No.
3, p
p: 2
12-2
16, 2
011.
•
Kap
adia
, Ziv
anov
ic, V
errie
r, an
d Po
povi
c, A
ccep
ted
for
publ
ishi
ng in
Top
ics
in S
pina
l Cor
d In
jury
Reh
abili
tatio
n in
Apr
il 20
11.
•R
esto
ratio
n of
vol
unta
ry h
and
func
tion
in
inco
mpl
ete
SC
I is
poss
ible
usi
ng F
ES
. •
Impr
ovem
ents
in h
and
func
tion
and
ther
eby
incr
ease
in le
vel o
f ind
epen
denc
e ar
e si
gnifi
cant
w
ith F
ES
trai
ning
.
Con
clus
ions
Co
ntr
ol
Gro
up
In
terv
en
tio
n
Gro
up
T
ES
T
Befo
re
Aft
er
Befo
re
Aft
er
p v
alu
es
(bo
th
han
ds)
FIM
Self
Care
Su
b-
sco
res
7.8
17.8
8.1
28.2
0.0
15
SC
IM S
elf
Care
Su
b-
sco
re
3.3
6.4
1.9
12.1
<
0.0
001
TR
I-H
FT
Co
mp
on
en
ts
10 O
bje
cts
27.2
38.5
37.1
53.8
0.0
54
Recta
ng
ula
r B
loc
ks
29.3
38.4
34.7
49.7
0.1
24
Instr
um
ente
d C
ylin
der
Ab
le t
o H
old
1.9
0
1.3
3
1.0
1.7
0.0
33
Instr
um
en
ted
Cy
lin
der
To
rqu
e V
alu
es (
Nm
) 0.2
6
2.5
9
0.2
6
1.1
3
0.4
24
7
Cre
dit
Card
A
ble
to
Ho
ld
1.3
3
1.4
1
1.0
1.7
0.0
35
Cre
dit
Card
F
orc
e V
alu
es
(N
) 2.6
7
8.7
6
4.4
2
12.5
0.4
22
Wo
od
en
Bar
Ab
le t
o H
old
0.6
3
0.9
6
0.8
1.5
0.0
65
Wo
od
en
Bar
Th
um
b
Dir
ecti
on
L
en
gth
Valu
es (
cm
) 2.8
8
10.5
1.6
7
10.9
4
0.6
22
Wo
od
en
Bar
Lit
tle
Fin
ger
Dir
ec
tio
n
Len
gth
Valu
es (
cm
) 3.1
7
11.8
5
5.5
6
12.7
8
0.7
67
T
he a
utho
rs a
ckno
wle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he P
rovi
ncia
l Reh
abili
tatio
n R
esea
rch
Pro
gram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io. T
he v
iew
s ex
pres
sed
do n
ot n
eces
saril
y re
flect
thos
e of
the
Min
istry
.
Part
ners
:
Can
adia
n In
stitu
tes
of H
ealth
Res
earc
h In
stitu
ts d
e re
cher
e en
san
té d
u C
anad
a N
atur
al S
cien
ces
and
Engi
neer
ing
Res
earc
h C
ounc
il of
Can
ada
Con
seil
de re
cher
ches
en
scie
nces
nat
urel
les
et e
n gé
nie
du C
anad
a
Min
istr
y of
Hea
lth
and
Long
Ter
m C
are Th
e vi
ews e
xpre
ssed
in th
is p
oste
r do
not n
eces
saril
y re
flect
thos
e of
any
of t
he g
rant
ing
agen
cies
.
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
y To
ront
o R
ehab
ilita
tion
Inst
itute
C
onta
ct: k
apad
ia.n
aaz@
toro
ntor
ehab
.on.
ca
ww
w.to
ront
o-fe
s.ca
TOR
ON
TO R
EHA
BIL
ITAT
ION
INST
ITU
TE’S
HA
ND
FU
NC
TIO
N T
EST
FOR
GR
OSS
MO
TOR
ASS
ESSM
ENT
Kap
adia
N¹,
Ziva
novi
c V¹,
Verr
ier M¹,
Pop
ovic
MR¹, ²
1 To
ront
o R
ehab
ilita
tion
Inst
itute
, 2 IB
BM
E -
Uni
vers
ity o
f Tor
onto
The
Tor
onto
Reh
abili
tatio
n In
stitu
te-H
and
Func
tion
Test
(TR
I-HFT
) is
a ne
w u
ser-
frien
dly
asse
ssm
ent t
ool d
esig
ned
to
eval
uate
uni
late
ral g
ross
mot
or fu
nctio
n of
th
e ha
nd to
per
form
pow
er g
rasp
and
pr
ecis
ion
grip
in te
trapl
egic
indi
vidu
als.
Intr
oduc
tion
Met
hods
•
Rel
iabi
lity,
val
idity
and
sen
sitiv
ity o
f TR
I-H
FT w
ere
eval
uate
d w
ithin
a ra
ndom
ized
co
ntro
l tria
l. •
Con
trol:
n=12
FE
S: n
=9.
• B
oth
grou
ps re
ceiv
ed 4
0 se
ssio
ns o
f th
erap
y. C
ontro
l gro
up re
ceiv
ed 2
hou
rs o
f co
nven
tiona
l occ
upat
iona
l the
rapy
(CO
T)
and
inte
rven
tion
grou
p re
ceiv
ed 1
hou
r of
CO
T pl
us 1
hou
r of F
ES
ther
apy.
•
Out
com
e m
easu
res
wer
e FI
M S
elf-c
are
Sub
-sco
re, S
CIM
Sel
f-car
e S
ub-s
core
and
TR
I-HFT
.
Res
ults
TRI-H
FT
Ref
eren
ces
Con
clus
ion
The
auth
ors
ackn
owle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he P
rovi
ncia
l Reh
abili
tatio
n R
esea
rch
Pro
gram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io. T
he v
iew
s ex
pres
sed
do n
ot n
eces
saril
y re
flect
thos
e of
the
Min
istry
.”
Left
han
d (P
re th
erap
y sc
ores
)
01020304050607080
010
2030
4050
6070
Ass
esso
r A
1
Assessor A2
Left
han
d (P
ost t
hera
py s
core
s)
01020304050607080
020
4060
80
Ass
esso
r A
1
Assessor A2
(Po
st
the
rap
y)
05101520
25
30
35
40
020
40
60
TR
I-H
FT (
10 o
bje
cts
)
(Po
st
the
rap
y)
05101520
020
40
60
TRI-‐HFT (10
objects
)
(Po
st
the
rap
y)
05101520
020
4060
TRI-‐HFT (10
objects
)
• Th
e TR
I-HFT
con
sist
s of
two
parts
:
1)
The
firs
t par
t of t
he te
st a
sses
ses
the
patie
nts’
abi
lity
to m
anip
ulat
e ob
ject
s th
at
they
may
enc
ount
er in
thei
r dai
ly li
ves
usin
g a
late
ral p
inch
, pul
p pi
nch
or
palm
ar g
rasp
.
2)
The
sec
ond
part
of th
e te
st m
easu
res
the
stre
ngth
of t
heir
late
ral p
inch
or p
ulp
pinc
h, a
nd p
alm
ar g
rasp
. •
The
entir
e ev
alua
tion
for b
oth
hand
s ca
n be
com
plet
ed in
less
than
30
min
utes
.
Left
Han
d (r
val
ues)
R
ight
Han
d
(r v
alue
s)
Con
stru
ct V
alid
ity
TRI-H
FT a
nd F
IM s
elf-
care
sub
-sco
re
0.73
0.
56
TRI-H
FT a
nd S
CIM
se
lf-ca
re s
ub-s
core
0.
62
0.48
Inte
r-ra
ter R
elia
bilit
y 0.
99
0.99
• TR
I-HFT
is a
sim
ple,
relia
ble
and
valid
m
easu
re.
• TR
I-HFT
take
s le
ss th
an 3
0 m
inut
es to
be
adm
inis
tere
d an
d it
is a
pub
lical
ly
avai
labl
e te
st.
• TR
I-HFT
was
foun
d to
be
high
ly
resp
onsi
ve to
cha
nge.
(Po
st
the
rap
y)
05101520
25
30
35
40
020
40
60
TR
I-H
FT (
10 o
bje
cts
)
• P
opov
ic M
R, K
apad
ia N
, Ziv
anov
ic V
, Fur
lan
JC, C
rave
n B
C a
nd
McG
illiv
ray
C, .
Func
tiona
l Ele
ctric
al S
timul
atio
n th
erap
y of
Vo
lunt
ary
Gra
spin
g Ve
rsus
Onl
y C
onve
ntio
nal R
ehab
ilita
tion
for
Pat
ient
s W
ith S
ubac
ute
Inco
mpl
ete
Tertr
aple
gia:
A R
ando
miz
ed
Clin
ical
Tria
l Neu
rore
habi
l Neu
ral R
epai
r. 20
11 F
eb 8
. [E
pub
ahea
d of
prin
t]
• K
apad
ia N
M, Z
ivan
ovic
V, F
urla
n J,
Cra
ven
BC
, McG
illiv
ray
C a
nd
Pop
ovic
MR
Fun
ctio
nal e
lect
rical
stim
ulat
ion
ther
apy
for g
rasp
ing
in tr
aum
atic
inco
mpl
ete
spin
al c
ord
inju
ry: a
rand
omiz
ed c
ontro
l tri
al.
• P
opov
ic M
.R.,
Thra
sher
T.A
., Zi
vano
vic
V., T
akak
i J.,
and
Haj
ek V
., “N
euro
pros
thes
is fo
r res
torin
g re
achi
ng a
nd g
rasp
ing
func
tions
in
seve
re h
emip
legi
c pa
tient
s.” N
euro
mod
ulat
ion.
200
5;8(
1):6
0-74
.
RES
PIR
ATO
RY
FUN
CTI
ON
INC
REA
SES
WIT
H T
RU
NK
MU
SCLE
STI
MU
LATI
ON
A
MO
NG
IND
IVID
UA
LS W
ITH
SPI
NA
L C
OR
D IN
JUR
YM
J K
uipe
rs1
M M
ilose
vic4
MR
Pop
ovic
3,4,
5 M
C V
errie
r1,2,
3,5
Dep
artm
ents
of P
hysi
olog
y1, P
hysi
cal T
hera
py2 ,
Reh
abili
tatio
n Sc
ienc
e3, a
nd th
e In
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eerin
g4,
Uni
vers
ity o
f Tor
onto
; Tor
onto
Reh
abili
tatio
n In
stitu
te-U
HN
, Lyn
dhur
st C
ente
r5, T
oron
to, O
ntar
io, C
anad
a.
Alte
red
brea
thin
g fo
llow
ing
spin
al c
ord
inju
ry (S
CI)
depe
nds
on th
e le
vel a
nd c
ompl
eten
ess
of in
jury
. M
ulti-
syst
em m
otor
dys
func
tion,
incl
udin
g la
ck o
f co
ordi
nate
d ac
tivat
ion
of re
spira
tory
and
trun
k m
uscl
es, a
nd p
ostu
ral i
nsta
bilit
y in
hibi
t pro
per
diap
hrag
mat
ic fu
nctio
n. In
upr
ight
sitt
ing,
this
resu
lts
in re
duce
d ex
pira
tory
cap
acity
1 an
d tid
al v
olum
e2.
Func
tiona
l ele
ctric
al s
timul
atio
n (F
ES
) im
prov
es s
ittin
g po
stur
e, in
clud
ing
pelv
ic o
rient
atio
n an
d sp
inal
al
ignm
ent,
and
lung
cap
acity
dur
ing
a fo
rced
ex
pira
tory
man
oeuv
re3 .
How
ever
, res
pira
tory
func
tion
rem
ains
to b
e in
vest
igat
ed a
mon
g in
divi
dual
s w
ith S
CI
durin
g th
e ap
plic
atio
n of
FE
S.
Intr
oduc
tion
SCIs
: For
par
ticip
ants
with
com
plet
e S
CI,
FES
app
ears
to h
ave
a po
sitiv
e ef
fect
on
VE
. SC
I1, w
ho w
as th
e on
ly p
artic
ipan
t with
an
inco
mpl
ete
inju
ry, d
id n
ot d
emon
stra
te a
ny m
eani
ngfu
l cha
nge
in
resp
irato
ry fu
nctio
n w
ith F
ES
. The
re w
as a
n in
crea
se in
mea
sure
s of
resp
irato
ry fu
nctio
n w
ith F
ES
in p
artic
ipan
ts S
CI2
and
SC
I3:
SC
I2 a
nd S
CI3
dem
onst
rate
d in
crea
ses
in V
T an
d R
R, d
epen
ding
on
the
site
of s
timul
atio
n. V
E in
crea
sed
for a
ll pa
rtici
pant
s w
ith th
e ap
plic
atio
n of
FE
S fr
om 1
%-2
6%. T
he p
rom
inen
t cha
nges
in V
E fo
r S
CI2
and
SC
I3 m
ay b
e du
e to
the
com
plet
enes
s o
f the
ir in
jurie
s.
The
ultim
ate
goal
is to
del
inea
te c
usto
miz
ed s
timul
atio
n pa
radi
gms
that
are
pat
ient
-spe
cific
to o
ptim
ize
resp
irato
ry fu
nctio
n du
ring
func
tiona
l act
iviti
es. T
he b
enef
its o
f ach
ievi
ng o
ptim
al re
spira
tory
fu
nctio
n ar
e si
gnifi
cant
and
may
par
alle
l ach
ievi
ng o
ptim
al p
ostu
re
(i.e.
upr
ight
vs.
slo
uch
sitti
ng),
as d
emon
stra
ted
in a
ble-
bodi
ed
indi
vidu
als.
Indi
vidu
als
with
hig
h-le
vel,
mot
or a
nd s
enso
ry
com
plet
e S
CI m
ay b
enef
it fro
m tr
unk
mus
cle
FES
giv
en th
e po
tent
ial t
o in
crea
se V
E. I
t may
be
poss
ible
to u
se F
ES
to im
prov
e V
E a
nd th
eref
ore
phys
iolo
gica
l hom
eost
asis
. Fur
ther
stu
dies
are
re
quire
d to
det
erm
ine
if th
ese
prel
imin
ary
findi
ngs
can
be
repr
oduc
ed, a
nd m
ust i
nclu
de p
artic
ipan
ts w
ith d
iffer
ent l
evel
s an
d co
mpl
eten
ess
of S
CI t
o de
term
ine
spec
ifici
ty o
f stim
ulat
ion
para
met
ers
and
resu
ltant
cha
nges
in d
iffer
ent c
ompo
nent
s of
re
spira
tory
func
tion.
Dis
cuss
ion
Obj
ectiv
e1)
Des
crib
e th
e ef
fect
s of
sitt
ing
post
ure
on
resp
irato
ry fu
nctio
n in
abl
e-bo
died
indi
vidu
als
(AB
s).
2) T
est t
he fe
asib
ility
of u
sing
FE
S to
cha
nge
resp
irato
ry fu
nctio
n in
indi
vidu
als
with
SC
I.
Part
icip
ants
& P
arad
igm
Res
pira
tory
func
tion,
incl
udin
g tid
al v
olum
e (V
T),
resp
irato
ry ra
te (R
R),
and
min
ute
vent
ilatio
n (V
E),
was
m
easu
red
durin
g 60
s tri
als
of u
nsup
porte
d si
tting
.•A
Bs
(N=1
0): u
prig
ht s
ittin
g, S
ITU
P ; s
louc
h si
tting
, SIT
SL•S
CIs
(N=3
): un
supp
orte
d (S
ITU
N );
ante
rior-p
oste
rior
trunk
mus
cle
FES
, AP
-FE
S; m
edia
l-lat
eral
trun
k m
uscl
e FE
S, M
L-FE
S.
Tabl
e 2.
SC
Is re
spira
tory
func
tion
durin
g si
tting
Figu
re 1
. AB
s re
spira
tory
func
tion
durin
g si
tting
* A
diff
eren
ce o
f <5%
was
not
con
side
red
mea
ning
ful.
Age
(y)
Inj
ury
leve
l D
ur (m
) P
ack-
year
s
AB
s 31± 5
.9
--
--
6.3±
3.7
SC
I1
25
C5-
I
31
8
.0
SC
I2
25
C5-
MC
3
6
non
-sm
oker
SC
I3
33
C4-
MC
192
2
.3
Tabl
e 1.
Par
ticip
ant c
hara
cter
istic
s
VT
RR
VE
SC
I1
SIT
UN
AP
-FE
SM
L-FE
S
0.51
↓3%
*↓
2% *
18.8
↑
3% *
↑
6%
9.7
↑
1% *
↑
3% *
SC
I2
SIT
UN
AP
-FE
SM
L-FE
S
0.81
↑
10%
↑
19%
11.2
↑
9%↓
2% *
9.0
↑
12%
↑
15%
SC
I3
SIT
UN
AP
-FE
SM
L-FE
S
0.75
↑
7%↓
8%
13.8
↑
5%↑
32%
9.7
↑
14%
↑
26%
Ref
eren
ces
1 Lin
et a
l. 20
06.A
rch
Phy
s M
ed R
ehab
il 87
(4) 5
04-9
2 Win
slow
and
Roz
ovsk
y 20
03. A
m J
Phy
s M
ed R
ehab
82(
10) 8
03-1
43 T
riolo
et a
l. 20
09. A
rch
Phy
s M
ed R
ehab
il 90
(2) 3
40-7
Ack
now
ledg
emen
tsTh
is re
sear
ch w
ould
not
be
poss
ible
with
out f
undi
ng fr
om: N
SER
C
Alex
ande
r Gra
ham
Bel
l Can
ada
Gra
duat
e Sc
hola
rshi
p an
d C
IHR
gra
nts
1291
79, 9
7953
, 940
18. T
he a
utho
rs a
lso
ackn
owle
dge
the
supp
ort o
f TR
I w
ho re
ceiv
es fu
ndin
g un
der t
he P
rovi
ncia
l Reh
abilit
atio
n R
esea
rch
Pro
gram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io. T
he
view
s ex
pres
sed
do n
ot n
eces
saril
y re
flect
thos
e of
the
Min
istry
.
Res
ults
AB
s: D
urin
g S
ITU
P , V
T in
crea
sed
by 1
4% c
ompa
red
to S
ITSL
(0
.70±
0.27
l vs.
0.6
1±0.
19l,
p=0.
009*
*); R
R d
id n
ot c
hang
e si
gnifi
cant
ly b
etw
een
SIT
UP
and
SIT
SL (1
4±3.
47m
in-1
vs.
15±2
.97m
in-1
, p=0
.18)
. S
imila
rly, V
E w
as 6
% g
reat
er d
urin
g S
ITU
P c
ompa
red
to S
ITSL
(9.4
0±2.
20l/m
in v
s. 8
.83±
1.60
l/min
, p=
0.01
*).
Partners:
Ca
nad
ian
In
sti
tute
s o
f H
ealth
Re
se
arc
h
Insti
tuts
de
re
ch
ere
en
san
téd
u C
an
ad
a
Natu
ral S
cie
nce
s a
nd
En
gin
ee
rin
g R
ese
arc
h C
ou
ncil o
f C
an
ad
a
Co
nse
ild
e r
ech
erc
he
se
n s
cie
nce
s n
atu
relle
se
t e
n g
én
ied
u C
an
ad
a
Min
istr
y o
f H
ealt
h
an
d L
on
g T
erm
Care The views expressed in this poster do not necessarily reflect those of any of the granting agencies.
Re
ha
bilit
ati
on
En
gin
ee
rin
g L
ab
ora
tory
Ins
titu
te o
f B
iom
ate
ria
ls a
nd
Bio
me
dic
al
En
gin
ee
rin
g,
Un
ive
rsit
yo
f T
oro
nto
To
ron
to R
eh
ab
ilit
ati
on
In
sti
tute
Co
nta
ww
w.t
oro
nto
fes
.ca
Vis
ua
liza
tio
n o
f T
run
k M
us
cle
Syn
erg
ies
du
rin
g S
itti
ng
Pe
rtu
rba
tio
ns
M. M
ilo
sevic
1,2
, E
. S
ejd
ic3, K
. M
asan
i2, M
. K
yan
4, K
.M. M
cC
on
ville
1,4
, M
.R. P
op
ovic
1,2
[1] Masani, K., Sin, V. W., Vette, A. H., Thrasher, T. A., Kawashima, N.,
Morris, A., R. Preuss, and M. R. Popovic(2009). Postural reactions
of the trunk muscles to multi-directional perturbations in sitting. Clin
Biomech(Bristol, Avon), 24(2), 176-182.
[2] Preuss, R., & Fung, J. (2008). Musculature and biomechanics of the
trunk in the maintenance of upright posture. J Electromyogr Kinesiol,
18(5), 815-828.
Refe
ren
ces
Vis
ua
liza
tio
n o
f T
run
k M
us
cle
Syn
erg
ies
-EMG pattern for bilateral: rectusabdominis(RA),
external oblique (EO), and internal oblique (IO), thoracic
erector spinae(T9) and lumbar erector spinae(L3)
Resu
lts
Pe
rtu
rba
tio
n C
lus
ters
-clustering based on ‘winning’directions on each node
a) all directions (b) ‘winning’cluster for 8 directions
-spatial proximity of clusters = similarity of synergies
b)
a)
5 1
7
3
64
82
Syn
erg
y C
om
pa
ris
on
-Euclidian distance between the center of each cluster
-implies postural synergy similarities and differences
-small distance = similar; large distance = dissimilar
Dir
ec
tio
n 1
0123451
2
3
4
5
6
7
8
Dir
ecti
on
2
0123451
2
3
4
5
6
7
8
Dir
ecti
on
5
0123451
2
3
4
5
6
7
8
Dir
ecti
on
6
0123451
2
3
4
5
6
7
8
Dir
ec
tio
n 1
0123451
2
3
4
5
6
7
8
Dir
ecti
on
2
0123451
2
3
4
5
6
7
8
Dir
ecti
on
5
0123451
2
3
4
5
6
7
8
Dir
ecti
on
6
0123451
2
3
4
5
6
7
8
Dir
ecti
on
7
0123451
2
3
4
5
6
7
8
Dir
ecti
on
8
0123451
2
3
4
5
6
7
8
Dir
ecti
on
3
0123451
2
3
4
5
6
7
8
Dir
ecti
on
4
0123451
2
3
4
5
6
7
8
Dir
ecti
on
7
0123451
2
3
4
5
6
7
8
Dir
ecti
on
8
0123451
2
3
4
5
6
7
8
Dir
ecti
on
3
0123451
2
3
4
5
6
7
8
Dir
ecti
on
4
0123451
2
3
4
5
6
7
8
Tru
nk
Mu
sc
le R
es
po
ns
e
-direction-dependant differences during sitting [1,2]
-adjacent directions most similar responses
-progressively more dissimilar as perturbations change
Syn
erg
y V
isu
ali
za
tio
n
-SOM encodes complex muscle synergies
-describes synergistic muscle relationships at a glance
-clusters could uncover deviant neuromuscular responses
-compare muscle synergies of patients (eg. SCI, stroke)
Dis
cu
ssio
n
Mu
sc
le S
yn
erg
ies
-Synergy= pattern of co-activations of muscles
-multiple muscles activate during sitting perturbations
-P
rob
lem
:how to compare postural synergies?
Vis
ua
liza
tio
n u
sin
g S
elf
Org
an
izin
g M
ap
s (
SO
M)
-SOM: encodes of data on the map
-Visualization:data summary on a 2D map projection
Intr
od
ucti
on
Ob
jec
tive
s:
-visualization of sitting trunk muscle synergies
-compare 8 perturbation direction synergies
EMG feature
SOM
Visualization
+ Clusters
EMG
data
Input data:
Output layer:
EMG feature
SOM
Visualization
+ Clusters
EMG
data
Input data:
Output layer:
Ex
pe
rim
en
t [1]
-sample: N=13; healthy
-sitting perturbations: 8 directions
-EMG: 10 trunk muscles (bilateral)
Meth
od
s
•T
rain
ing
�EMG (all) + directions (8 direction)
-input data (
xn): 104 input vectors
-output layer: 5x5 nodes have weight vectors w
j
-SOM: groups similar data patterns together
SO
M
-SOMToolbox,Helsinki University of Technology
-normalized input data
wj(n+1) = w
j(n) + hcj(n).[xn–
wj(n)]
Ou
tpu
t L
aye
r
-5x5 hexagonal map (2-D)
Inp
ut
Da
ta
-EMG filtering: rectification, low-pass & window filter
-feature: phasicEMG response after perturbation
•V
isu
ali
za
tio
n �
density / clusters analysis
2 46
8
BACKWARD
FORWARD
LEFT
RIGHT
12
3
45
6
7
8
Direction 8
Direction 1
Direction 2
Direction 6
Direction 5
Direction 4
Direction 3
Direction 7
1In
sti
tute
fo
r B
iom
ate
ria
ls a
nd
Bio
me
dic
al
En
gin
ee
rin
g, U
niv
ers
ity o
f T
oro
nto
; 2
Re
ha
bil
ita
tio
n E
ng
ine
eri
ng
La
bo
rato
ry,
To
ron
to R
eh
ab
ilit
ati
on
In
sti
tute
; 3
De
pa
rtm
en
t o
f E
lec
tric
al
an
d C
om
pu
ter
En
gin
ee
rin
g,
Un
ive
rsit
y o
f
Pit
tsb
urg
h;
4 E
lec
tric
al
an
d C
om
pu
ter
En
gin
ee
rin
g D
ep
art
me
nt,
Rye
rso
n U
niv
ers
ity
Part
ners
:
Can
ad
ian
In
sti
tute
s o
f H
ealt
h R
esearch
Insti
tuts
de r
ech
ere e
n s
an
té
du
Can
ad
a
Natu
ral S
cie
nces an
d E
ng
ineerin
g R
esearch
Co
un
cil o
f C
an
ad
a
Co
nseil d
e r
ech
erch
es e
n s
cie
nces n
atu
relles e
t en
gén
ied
u C
an
ad
a
Min
istr
y o
fH
ealt
h
an
d L
on
g T
erm
Care
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
yIn
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eeri
ng, U
nive
rsity
of T
oron
toT
oron
to R
ehab
ilita
tion
Inst
itute
Con
tact
:milo
s.pop
ovic
@ut
oron
to.c
aw
ww
.toro
nto-
fes.c
a
DO
ES F
UN
CTI
ON
AL
ELEC
TRIC
AL
STIM
ULA
TIO
N O
F TR
UN
K M
USC
LES
ALT
ER
RES
PIR
ATIO
N IN
SPI
NA
L C
OR
D IN
JUR
Y?
Kui
pers
MJ
1 ; W
u N
4 ; P
opov
ic M
R 3,
4,5 ;
Ver
rier
MC
1,2,
3,5 .
Rel
atio
nshi
p be
twee
n Po
stur
al C
ontr
ol a
nd R
espi
rato
ry C
apac
ity
Dep
artm
ents
of P
hysi
olog
y 1 ,
Phys
ical
The
rapy
2, a
nd R
ehab
ilita
tion
Scie
nce3 ,
Facu
lty o
f Med
icin
e, IB
BM
E4 ,
Uni
vers
ity o
f Tor
onto
; Tor
onto
Reh
abili
tatio
n In
stitu
te5 ,
Tor
onto
, ON
, Can
ada.
•Indi
vidu
als w
ith S
CI a
t or a
bove
L1
expe
rienc
e lo
ss o
f vo
lunt
ary
cont
rol o
f tru
nk m
uscl
es fr
om a
troph
y an
d pa
raly
sis
•Dur
ing
sitti
ng, p
ostu
ral c
ontro
l is c
ompr
omis
ed; i
ndiv
idua
ls
assu
me a
subo
ptim
al p
ostu
re to
mai
ntai
n si
tting
bal
ance
•Lum
bar k
ypho
sis a
nd p
oste
rior p
elvi
c til
t lea
d to
lim
itatio
ns
in fu
nctio
nal a
bilit
y an
d re
duce
d re
spira
tory
cap
acity
•Cur
rent
inte
rven
tions
for c
orre
ctiv
e po
stur
al c
ontro
l are
fu
nctio
nally
rest
rictiv
e •Im
plan
ted
stim
ulat
ing
elec
trode
s del
iver
ing
FES
to re
ctus
ab
dom
inus
and
ere c
tor s
pina
e has
impr
oved
ver
tebr
al a
lignm
ent
and
resp
irato
ry c
apac
ity in
a si
ngle
SC
I sub
ject
whi
le si
tting
•Tra
nscu
tane
ous f
unct
iona
l ele
ctric
al st
imul
atio
n (F
ES) i
s a
non-
inva
sive
tech
niqu
e for
trai
ning
mot
or re
cove
ry in
SC
I
Intr
oduc
tion
Tas
ks:
1a
. Qui
et si
tting
1b Q
uiet
sitti
ng w
/ FES
2a. C
ompl
ex c
ogni
tive
task
2b. C
CT
w/ F
ES
•Sub
ject
s with
:•L
evel
C5-
T12
inju
ry•A
SIA
A-D
impa
irmen
t•N
o pr
ior r
espi
rato
ry d
isea
se
Incl
usio
n C
rite
ria
Ref
eren
ces
Hob
son
and
Toom
s 19
92. S
pine
(Phi
la P
a 19
76) 1
7(3)
. K
irchb
erge
r et a
l. 20
09. S
pina
l Cor
d 48
. W
insl
ow a
nd R
ozov
sky
2003
. Am
J Ph
ys M
ed R
ehab
82.
Popo
vic
et a
l. Sp
inal
Cor
d (2
006)
44.
Han
kins
on et
al.
1999
. Am
J R
espi
r Crit
Car
e M
ed15
9.B
aydu
r et a
l. 20
01. J
App
l Phy
siol
90.
Tr
iolo
et a
l. 20
09. A
rch
Phys
Med
Reh
abil
90.
Ack
now
ledg
emen
tsTh
is re
sear
ch w
ould
not
be
poss
ible
with
out f
undi
ng fr
om:
NSE
RC
Ale
xand
er G
raha
m B
ell C
anad
a Gra
duat
e Sc
hola
rshi
p an
d C
IHR
gra
nts 1
2917
9, 9
7953
, 940
18.
•In S
CI,
resp
irato
ry im
pairm
ents
cor
rela
te w
ith in
jury
leve
l and
w
orse
n w
ith u
prig
ht (s
ittin
g) p
ostu
re: r
estri
ctiv
e na
ture
of
impa
irmen
ts m
ean
FEV
1an
d FV
C d
ecre
ase
prop
ortio
nally
so
the
ratio
may
be
norm
al o
r inc
reas
ed•In
ord
er to
pro
ve e
ffic
acy,
tran
scut
aneo
us F
ES m
ust f
acili
tate
si
mila
r gai
ns in
resp
irato
ry c
apac
ity a
s cur
rent
inte
rven
tions
: i.e
. ch
ange
on
the
mag
nitu
de o
f 10+
% in
crea
se in
FEV
1an
d 20
+%
incr
ease
in F
VC
•Oth
er im
prov
emen
ts o
f sur
face
FES
-ass
iste
d si
tting
for
indi
vidu
als w
ith S
CI m
ay in
clud
e an
aes
thet
ic a
nd c
orre
cted
-no
rmal
pos
ture
; pre
ssur
e re
lief o
ff th
e co
ccyx
; and
redu
ctio
n in
in
cide
nce o
f pre
ssur
e ul
cers
. •B
y tra
inin
g w
ith F
ES in
a m
ultit
ask
para
digm
, the
re m
ay b
e im
prov
emen
ts in
upp
er li
mb
func
tion
from
ach
ievi
ng b
ette
r po
stur
al c
ontro
l in
a si
tting
pos
ition
. •T
he b
enef
its o
f ach
ievi
ng si
tting
bal
ance
are
sign
ifica
nt,
cont
ribut
ing
to in
depe
nden
ce, i
mpr
oved
hea
lth st
atus
, and
w
ellb
eing
in th
e SC
I pop
ulat
ion
Dis
cuss
ion
Met
hods
•Dur
ing
each
tria
l, da
ta w
ill b
e re
cord
ed: k
inem
atic
mea
sure
s of
hea
d po
sitio
n, v
erte
bral
alig
nmen
t, an
d pe
lvic
tilt;
re
spira
tory
mea
sure
s of f
orce
d vi
tal c
apac
ity, f
orce
d ex
pira
tory
vol
ume
in o
ne se
cond
, and
the
ratio
of t
he tw
o va
lues
(FV
C, F
EV1,
and
FEV
1/FV
C);
dyna
mic
sitti
ng
stab
ility
mea
sure
d as
cen
ter o
f pre
ssur
e (C
OP)
. Fi
gure
1.Pl
ots
com
parin
gm
ean
norm
ativ
ere
spira
tory
valu
esFE
V1
and
FEV
1/FV
Cby
age
coho
rtto
:ave
rage
valu
esfo
rsub
ject
sw
ithpa
rapl
egia
(red
lines
)and
tetra
pleg
ia(b
lack
lines
);an
dva
lues
for
asi
ngle
tetra
pleg
icsu
bjec
tw
ith(r
eddo
t)an
dw
ithou
t(b
lack
dot)
impl
ante
dtru
nkm
uscl
eFE
S.Fi
gure
and
data
adap
ted
from
:H
anki
nson
etal
.199
9;B
aydu
reta
l.20
01;T
riolo
etal
.200
9.
Ince
ntiv
e sp
irom
etry
Mul
ti-ch
anne
l st
imul
atio
n
Forc
e pl
ate
Mot
ion
capt
ure
syst
em(n
ot sh
own)
Hyp
othe
sis
We
hypo
thes
ize
that
tran
scut
aneo
us F
ES o
f sel
ect t
runk
m
uscl
es w
ill fa
cilit
ate p
ostu
ral c
ontro
l and
gai
ns in
resp
irato
ry
capa
city
whi
le s
ittin
g
Exp
erim
enta
l Par
adig
m
Nat
ural
Sci
ence
s an
d E
ngin
eeri
ng R
esea
rch
Cou
ncil
of C
anad
aC
onse
ilde
rech
erch
esen
sci
ence
s na
ture
lles
et e
n gé
nie
du C
anad
a
Pilo
t Stu
dies
of T
asks
Two
indi
vidu
als,
one
abl
e-bo
died
and
one
chr
onic
SC
I, pe
rform
ed re
peat
ed
trial
s of
sta
tic a
nd d
ynam
ic s
ittin
g ta
sks
on th
e fo
rce
plat
e. R
epre
sent
ativ
e C
OP
dia
gram
s fo
r eac
h ty
pe o
f tas
k ar
e sh
own
belo
w.
Doe
s su
rface
FE
S h
ave
an e
ffect
on
sitti
ng C
OP
in a
ble-
bodi
ed in
divi
dual
s?
Doe
s pe
rform
ing
PFTs
affe
ct s
ittin
g C
OP
in in
divi
dual
s w
ith c
hron
ic S
CI?
How
do
dyna
mic
act
iviti
es a
ffect
sitt
ing
CO
P in
indi
vidu
als
with
chr
onic
SC
I?A
CE
BD
F
Figu
re 2
. Cen
ter
of p
ress
ure
excu
rsio
ns fo
r an
indi
vidu
al w
ith c
hron
ic S
CI d
urin
g m
ultip
le
trial
s of
forw
ard
reac
hing
(A, B
), la
tera
l rea
chin
g (C
, D),
and
post
erio
r lea
ning
(E, F
).
AB
Figu
re 1
. Cen
ter o
f pre
ssur
e ex
curs
ions
for a
n ab
le-b
odie
din
divi
dual
dur
ing
quie
t sitt
ing
(A) a
nd w
ith F
ES (B
).
AB
C
Figu
re 2
. C
ente
r of
pre
ssur
e ex
curs
ions
for
an
indi
vidu
al w
ith c
hron
ic S
CI
durin
g qu
iet
sitti
ng (A
), pe
rform
ing
a PF
T be
fore
(B) a
nd a
fter (
C) a
ser
ies
of fu
nctio
nal r
each
ing
task
s.
Link
ing
FES-
assi
sted
sitt
ing
stab
ility
and
bre
athi
ng in
spi
nal c
ord
inju
ryM
.J. K
uipe
rs1 ,
M.R
. Pop
ovic
3,4 ,
M.C
. Ver
rier1,
2,4
Uni
vers
ity o
f Tor
onto
, Fac
ulty
of M
edic
ine,
Dep
artm
ents
of P
hysi
olog
y1 an
d Ph
ysic
al T
hera
py2 ;
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring3 ;
Toro
nto
Reh
abili
tatio
n In
stitu
te4 .
Toro
nto
Reh
ab is
a te
achi
ng a
nd
rese
arch
hos
pita
l affi
liate
d w
ith th
e U
nive
rsity
of T
oron
to.
Res
earc
h Pr
oble
mLo
ss o
f vol
unta
ry c
ontro
l of t
he tr
unk
mus
cles
due
to p
aral
ysis
follo
win
g sp
inal
cor
d in
jury
(SC
I) is
ass
ocia
ted
with
abn
orm
al p
ostu
re, i
mpa
ired
sitti
ng
stab
ility
and
redu
ced
brea
thin
g ca
paci
ty d
urin
g si
tting
. Spe
cific
ally
, tho
raco
- lu
mba
r kyp
hosi
s an
d po
ster
ior r
otat
ion
of th
e pe
lvis
are
feat
ures
of a
typi
cal
mal
adap
tive
post
ure
in S
CI1
that
allo
w in
divi
dual
s w
ithou
t tru
nk c
ontro
l to
mai
ntai
n si
tting
bal
ance
yet
lim
its s
ome
func
tiona
l act
ivity
2,3 .
A s
imila
r po
stur
e in
hea
lthy
indi
vidu
als
resu
lts in
sig
nific
ant d
ecre
ases
in lu
ng
func
tion4 ,w
hich
is e
vide
nce
of th
e ad
vers
e ef
fect
s of
suc
h a
posi
tion
on
brea
thin
g ca
paci
ty. A
fter a
n S
CI,
trunk
mus
cle
para
lysi
s le
ads
to lo
ss o
f ab
dom
inal
mus
cle
tone
suc
h th
at in
an
uprig
ht p
ositi
on th
e ef
fect
of g
ravi
ty
and
incr
ease
d ab
dom
inal
com
plia
nce
caus
es a
cau
dal s
hift
of th
e ab
dom
inal
co
nten
ts5 .
This
shi
ft ef
fect
ivel
y re
mov
es th
e fu
lcru
m o
f the
dia
phra
gm,
affe
ctin
g th
e ab
ility
of th
e di
aphr
agm
to d
o re
spira
tory
wor
k in
an
uprig
ht
posi
tion6 ,
furth
er c
ompr
omis
ing
the
resp
irato
ry s
yste
m. S
timul
atio
n of
sel
ect
trunk
mus
cles
usi
ng im
plan
ted
elec
trode
s ha
s co
ntrib
uted
to im
prov
emen
t of
verte
bral
alig
nmen
t and
has
faci
litat
ed g
ains
in fu
nctio
nal i
ndep
ende
nce
and
brea
thin
g ca
paci
ty7 .
Obj
ectiv
eTo
det
erm
ine,
usi
ng a
pro
of-o
f prin
cipl
e pa
radi
gm, t
he fe
asib
ility
of m
uscl
e-
spec
ific
func
tiona
l ele
ctric
al s
timul
atio
n (F
ES
) to
impr
ove
verte
bral
alig
nmen
t, en
hanc
e di
aphr
agm
atic
func
tiona
, and
opt
imiz
e pa
ram
eter
s of
task
-spe
cific
fu
nctio
ns. E
lect
rical
stim
ulat
ion
is b
eing
del
iver
ed to
sel
ect t
runk
mus
cles
via
su
rface
ele
ctro
des
to s
tiffe
n ab
dom
inal
mus
cles
and
trun
k ex
tens
ors.
V
erte
bral
alig
nmen
t, si
tting
sta
bilit
y an
d br
eath
ing
capa
city
are
bei
ng
mea
sure
d du
ring
stat
ic a
nd d
ynam
ic c
ondi
tions
of u
nsup
porte
d an
d FE
S-
assi
sted
sitt
ing.
Met
hodo
logy
Indi
vidu
als
will
be
aske
d to
par
ticip
ate
base
d on
the
follo
win
g cr
iteria
:
Exp
erim
enta
l Set
-up
Con
clus
ions
In
bot
h qu
iet s
ittin
g (Q
S) a
nd in
cent
ive
spiro
met
ry (I
S) c
ondi
tions
for a
ble-
bo
died
, sur
face
stim
ulat
ion
of th
e ab
dom
inal
and
trun
k ex
tens
or m
uscl
es
redu
ced
tota
l exc
ursi
on, v
eloc
ity a
nd fr
eque
ncy
of th
e C
OP
. The
larg
er C
OP
va
lues
mea
sure
d du
ring
quie
t sitt
ing
in c
hron
ic S
CI s
ugge
st le
ss s
ittin
g st
abilit
y in
com
paris
on to
abl
e-bo
died
dur
ing
unsu
ppor
ted
sitti
ng, a
s ex
pect
ed. I
n ch
roni
c S
CI,
the
frequ
ency
of t
he C
OP
was
dec
reas
ed a
nd th
e ex
curs
ion
and
velo
city
bot
h in
crea
sed
durin
g m
ultip
le tr
ials
of d
ynam
ic ta
sks.
It
is p
ossi
ble
that
indi
vidu
als
with
chr
onic
SC
I use
alte
rnat
ive
mot
or
stra
tegi
es to
com
plet
e dy
nam
ic ta
sks,
eac
h re
pres
entin
g a
char
acte
ristic
C
OP
.
Impl
icat
ions
Ulti
mat
ely,
our
goa
l is
to d
evel
op c
ompr
ehen
sive
sub
ject
-spe
cific
pro
toco
ls
to te
st th
e re
latio
nshi
p be
twee
n si
tting
sta
bilit
y an
d br
eath
ing
capa
city
in S
CI.
Th
e ne
xt s
tep
is to
test
sur
face
FE
S d
urin
g a
dyna
mic
par
adig
m to
det
erm
ine
the
acut
e ef
fect
s of
FE
S a
nd a
ltere
d si
tting
sta
bilit
y on
bre
athi
ng.
Ref
eren
ces
1. H
obso
n D
A, T
oom
s R
E. S
pine
(Phi
la P
a 19
76) 1
992;
17(
3): 2
93-8
. 2. C
hen
CL,
et a
l. A
rch
Phy
s M
ed R
ehab
il 20
03; 8
4(9)
: 127
6-81
. 3. K
ukke
SN
, Trio
lo R
J. IE
EE
Tra
ns N
eura
l S
yst R
ehab
il E
ng 2
004;
12(
2): 1
77-8
5. 4
. Lin
F, e
t al.
Arc
h P
hys
Med
Reh
abil
2006
; 87(
4):
504-
9. 5
. Bay
dur A
, Adk
ins
RH
, Mili
c-Em
ili J
. J A
ppl P
hysi
ol 2
001;
90(
2): 4
05-1
1. 6
. W
insl
ow C
, Roz
ovsk
y J.
Am
J P
hys
Med
Reh
abil
2003
; 82(
10):
803-
14. 7
. Trio
lo R
J, e
t al.
Arc
h P
hys
Med
Reh
abil
2009
; 90(
2): 3
40-7
.
Ack
now
ledg
emen
tsTh
e au
thor
s w
ould
like
to re
cogn
ize
the
follo
win
g in
stitu
tions
for p
rovi
ding
fund
ing
for t
he
com
plet
ion
of th
is re
sear
ch: O
ntar
io G
radu
ate
Scho
lars
hip
prog
ram
(MJK
), To
ront
o R
ehab
ilita
tion
Inst
itute
(TR
I) S
tude
nt S
chol
arsh
ip (M
JK),
Alex
ande
r Gra
ham
Bel
l Sc
hola
rshi
p fro
m N
atur
al S
cien
ces
and
Engi
neer
ing
Res
earc
h C
ounc
il (M
JK),
and
Can
adia
n In
stitu
tes
of H
ealth
Res
earc
h (g
rant
#12
9179
, MR
P). T
he a
utho
rs a
lso
ackn
owle
dge
the
supp
ort o
f TR
I who
rece
ives
fund
ing
unde
r the
Pro
vinc
ial R
ehab
ilita
tion
Res
earc
h Pr
ogra
m fr
om th
e M
inis
try o
f Hea
lth a
nd L
ong-
Term
Car
e in
Ont
ario
. The
vie
ws
expr
esse
d do
not
nec
essa
rily
refle
ct th
ose
of th
e M
inis
try. F
inal
ly, t
he a
utho
r wou
ld li
ke to
ex
tend
a th
ank
you
to N
oel W
u an
d th
e SC
I Mob
ility
Lab
for t
heir
assi
stan
ce.
Incl
usio
nEx
clus
ion
25-4
5 yr
sAb
le-b
odie
d or
SC
IAc
ute
or c
hron
ic re
spira
tory
illn
ess
[C5-
T12
inju
ry le
vel]
>10
pack
yea
r sm
okin
g hi
stor
y[P
ost-a
cute
pha
se]
BMI >
25
Dev
ice
Func
tion
Out
com
e m
easu
res
Plac
emen
tSt
imul
atin
g el
ectro
des
Artif
icia
l mus
cle
stim
ulat
ion
N/A
Rec
tus
abdo
min
is,
lum
bar e
rect
or s
pina
eFo
rce
plat
eSi
tting
sta
bilit
y as
sess
men
tC
ente
r of P
ress
ure
Dis
plac
emen
t, ra
nge,
ve
loci
ty
Sitti
ng s
urfa
ce
Mot
ion
anal
ysis
sy
stem
Verte
bral
alig
nmen
t as
sess
men
tH
ead
posi
tion
Spin
al c
urva
ture
Pelv
ic ti
lt
C7,
fore
head
L1, L
3, L
4, L
5, S
1A
SIS
, PS
ISSp
irom
eter
Res
pira
tory
ass
ess-
m
ent d
urin
g pu
lmon
ary
func
tion
test
(PFT
)
Exp
irato
ry v
olum
es
and
flow
rate
sFl
ow s
enso
r at m
outh
an
d no
se c
lip
Con
ditio
nN
o.
Tr
ials
Mea
n to
tal
excu
rsio
n (m
m)
Mea
nve
loci
ty(m
m/s
)M
ean
frequ
ency
(Hz)
QS
1 23
.358
11.
0381
1.14
81pr
e PF
T3
37.4
737
1.66
550.
3862
forw
ard
reac
h4
23.0
051
1.02
240.
1843
late
ral r
each
439
.072
11.
7365
0.40
89le
an b
ack
340
.216
91.
7874
0.26
51po
st P
FT3
25.2
793
1.12
350.
2838
PFT
arm
rais
e1
52.2
974
2.32
430.
3131
QS
fina
l1
34.9
224
1.55
211.
6529
Tabl
e 2.
Sum
mar
y of
mea
n C
OP
valu
es fo
r ind
ivid
ual w
ith c
hron
ic S
CI.
Con
ditio
nN
o.Tr
ials
Mea
n to
tal
excu
rsio
n (m
m)
Mea
nve
loci
ty(m
m/s
)M
ean
frequ
ency
(Hz)
QS
3 11
.171
10.
4965
1.02
21Q
S w
/ FE
S3
8.75
360.
3890
0.88
51IS
322
.684
61.
0082
1.60
45IS
w/ F
ES
317
.178
90.
7635
1.23
13
Tabl
e 1.
Sum
mar
y of
mea
n C
OP
val
ues
for
able
-bod
ied
indi
vidu
al u
nder
diff
eren
t c o
nditi
ons.
All
trial
s w
ere
60se
c in
dur
atio
n; e
ach
trial
con
ditio
n, q
uiet
sitt
ing
(QS)
and
in
crea
sed
resp
onse
effo
rt (IR
E), w
as re
peat
ed w
ith tr
ansc
utan
eous
FES
(w/ F
ES).
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
yCOP(mm)
xCO
P (m
m)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
xCO
P (m
m)
yCOP(mm)
Partners:
Canadian Institutes of Health Research Instituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of Canada Conseil de recherches en sciences naturelles et en génie du Canada
Physicians' Services Incorporated Foundation
Ministry of Health and Long Term Care
Methods – Inverse Dynamics Model:
• Focuses on the action of the lumbar spine [2] - AP: flexion-extension - ML: lateral bending - RT: axial rotation
• Six rigid bodies [2]: - L1 to L5 - Head-Arms-Thorax complex (HAT)
• 3 degrees-of-freedom (DOF) between at L5-PV joint [2] • 3 x 5 constraints (CT) at the remaining 5 joints [2]
Methods – Geometric Models and UBSP Data Source:
• High-resolution, transverse color images from the Male Visible Human (MVH) [1] • MVH anthropometrics: age 38; height 180 cm; weight 90 kg [1] • Image resolution: 0.144 mm x 0.144 mm x 1 mm [1]
Rehabilitation Engineering Laboratory, Institute of Biomaterials and Biomedical Engineering, University of Toronto Toronto Rehabilitation Institute Contact: [email protected] www.toronto-fes.ca
A Complete, Universal, and Verifiable Set of Upper Body Segment Parameters for Three-Dimensional Dynamic Modeling
Albert H. Vette, Takashi Yoshida, T. Adam Thrasher, Kei Masani, and Milos R. Popovic
Lyndhurst Centre, Toronto Rehabilitation Institute Institute of Biomaterials and Biomedical Engineering, University of Toronto Center for Neuromotor and Biomechanics Research, University of Houston
Conclusion
Background Dynamic models of the human trunk have been extensively used to investigate the biomechanics of lower back pain and postural instability in different populations. Despite their diverse applications, these models rely on intrinsic upper body segment parameters (UBSP), e.g., each segment’s mass-inertia characteristics. However, a comprehensive UBSP set allowing state-of-the-art, three-dimensional (3D) dynamic modeling does not exist to date.
Introduction
The purpose of this study was to establish a UBSP database that is accurate, complete, and universal, i.e., independent of pre-defined (lumped) trunk portions such as ‘upper trunk’ and ‘lower trunk’ (PART I). To demonstrate the practicality of the UBSP, they were finally implemented in a 3D dynamic model of the upper body to predict lumbar joint torques from experimental kinematics during perturbed sitting (PART II).
A comprehensive UBSP database has been obtained that can be implemented in 3D dynamic models to: (1) systemize thinking in postural control studies; (2) quantify the effect of impact forces on the head and trunk (e.g., during whiplash); (3) suggest population-specific experiments based on theoretical insights into trunk dynamics (e.g., regarding lower back pain); or (4) assess the feasibility of new surgical techniques (e.g., spinal fusion) and neuroprostheses (e.g., after spinal cord injury [3]).
Body Segmentation: • 24 vertebral trunk and head segments:
- 5 lumbar segments (L1 to L5) - 12 thoracic segments (T1 to T12) - 6 cervical segments and head (C2 to C7 and HD)
• 2 x 2 upper limb segments: - left and right upper arm (lUA and rUA) - left and right forearm-hand complex (lFA-H and rFA-H)
3D Geometric Models of: • MVH spinal vertebrae, spinal discs, and pelvis (PV) • MVH body shell
Results
Surface models of the MVH body shell and spine. The identified joint centers were used to define the vertebral trunk segments and upper limb segments for which respective mass-inertia characteristics were calculated using the geometric method.
Geometric Models and UBSP:
Discussion
References [1] Spitzer V et al, J Am Med Inform Assn 3, 118-130, 1996. [2] Wilkenfeld AJ et al, J Rehabil Res Dev 43, 139-152, 2006. [3] Masani K et al, Clin Biomech 24, 176-182, 2009.
We acknowledge the support of the Toronto Rehabilitation Institute, which receives funding under the Provincial Rehabilitation Research
Program from the Ministry of Health and Long-Term Care in Ontario. The views expressed do
not necessarily reflect those of the Ministry.
Identified Parameters: • Spinal joint centers • Segment masses • Location of segment center-of-masses • 3 x 3 moment of inertia tensor of segments
Experiments: • 1 subject with MVH anthropometrics • Horizontal perturbations during upright sitting • 8 perturbation directions, 5 trials each • Impulse force of ~200 N max, applied inferior to axillae
Joint Torque Estimation: • Inverse dynamics from kinematics to joint torques • 3 different dynamic implementations:
- Newton-Euler formulation - Lagrange formulation - Simulink & SimMechanics (Mathworks Inc.)
Inverse Dynamics:
Results of the inverse dynamics using the identified UBSP set. Shown are the AP and ML trunk angles and joint torques for an anterior-left diagonal perturbation during sitting. A visual inspection suggests that the torque outputs of the three different inverse dynamics implementations match very well (plotted on top of each other; R2 = 99.9999 %). It can also be seen that the AP torque traces are affected by the AP curvature of the spine.
Identified UBSP Set: • Complete with respect to 3D dynamic modeling (all required parameters identified) • Based on highly accurate 3D geometric models (1000 higher than existing sets) • Universal with respect to potential model definitions (parameters can be lumped together) • Uniquely verifiable and expandable (MVH dataset is freely accessible) L5
L4 L3 L2 L1
HAT
3 DOF 3 CT 3 CT
3 CT
3 CT
3 CT
Pelvis
Canadian Institutes of Health Research Instituts de recherche en santé du Canada
Natural Sciences and Engineering Research Council of Canada Conseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health and Long Term Care
Partners:
• Training à EMG (10 muscles) + directions (8 direction) - nodes (index j) have a weight vectors wj - input vector (xn), iteration n, compared to nodes - algorithm selects (index c) nearest node to the input xn - this weight vector and region hci(n) updated toward input xn
• Visualization à density / clusters analysis for all directions
Experiment [1, 2] - Sample: N=13, all healthy - Sitting perturbations: 8 directions - Record EMG: (5 trunk muscles x 2 sides)
Data processing - EMG filtering: rectification, low-pass & windowing filter - Model feature: max EMG response after perturbation
Methods
Spinal Cord Injury (SCI) - causes paralysis of lumbar musculature - trunk instability is a major problem with SCI - multiple muscles contribute to trunk stability
Data Visualization using Self Organizing Maps (SOM) - SOM - encodes statistical properties of data on the map - Visualization - data summary on a 2D map projection - Models - SOM models for closed-loop control of sitting
Introduction SOM Visualization
Results
SELF-ORGANIZING MAP FOR DATA MINING OF EMG TRUNK MUSCLE SIGNALS DURING SITTING
M. Milosevic1,2, K. Masani2, M. Kyan1, M.R. Popovic2,3, K.M. McConville1,2,3 1 Electrical and Computer Engineering Department, Ryerson University, Toronto, Canada
2 Rehabilitation Engineering Laboratory, Toronto Rehabilitation Institute, Toronto, Canada 3 Institute for Biomaterials and Biomedical Engineering, University of Toronto, Canada
Rehabilitation Engineering Lab, Toronto Rehabilitation Institute and Electrical and Computer Engineering, Ryerson University Contact: [email protected] www.toronto-fes.ca
EMG pre-processing
SOM training
Visualization Clustering ModelsextractionEMG
Qualitativeinformation
Quantitativeinformation
EMG pre-processing
SOM training
Visualization Clustering ModelsextractionEMG
Qualitativeinformation
Quantitativeinformation
Objectives: - SOM for electromyography (EMG) data mining - Visualization of high-dimension EMG data sets - Model trunk muscle activation patterns during sitting
SOM (SOMToolbox, Helsinki University of Technology): - 5x5 hexagonal map - normalized input - batch training mode - Euclidian measure
Input 6
wj (n+1) = wj (n) + hcj(n).[xn – wj(n)]
SOM Model - Clustering – based on ‘winning’ directions on each node - Gaussian regression models for all muscles from clusters - Normal distribution; consistent with [1, 2]
Activation pattern for abdominal muscles left (gray line) and right (black line): rectus abdominis (RA), external oblique (EO), and internal oblique (IO)
Activation pattern for back muscles for left (gray line) and right (black line): thoracic erector spinae (T9), lumbar erector spinae (L3)
[1] Masani K, et al. Postural reactions of the trunk muscles to multi- directional perturbations in sitting. Clin Biomech, 2009 [2] Preuss R, Fung J Musculature and biomechanics of the trunk in the maintenance of upright posture. J Electrom Kinesiol, 2008
References
SOM Visualization - describes synergistic muscle relationships at a glance - cluster could uncover deviant neuromuscular responses - can assess and grade trunk function in individuals
SOM Models - can model the activation patterns - opposing muscles stabilizes perturbations [1, 2]
Discussions
Tran
slat
iona
l Dam
ping
With
and
With
out
FES
- 2 W
ay A
NO
VA:
•M
ain
Fact
or: N
O F
ES
vs.
FE
S, p
= 0
.842
•
Mai
n Fa
ctor
: Dire
ctio
ns, p
<0.0
01
•In
tera
ctio
n: p
= 0
.559
Tors
iona
l Stif
fnes
s W
ith a
nd W
ithou
t FE
S - 2
Way
AN
OVA
: •
Mai
n Fa
ctor
: NO
FE
S v
s. F
ES
, p =
0.3
57
•M
ain
Fact
or: D
irect
ions
, p<0
.001
•
Inte
ract
ion:
p =
0.3
69
-B
oth
trans
latio
nal a
nd to
rsio
nal d
ampi
ng a
re s
igni
fican
tly d
iffer
ent b
etw
een
dire
ctio
ns
-B
oth
trans
latio
nal a
nd to
rsio
nal d
ampi
ng a
re n
ot s
igni
fican
tly d
iffer
ent b
etw
een
with
and
w
ithou
t FE
S
Ti
me=
0 fo
r ana
lysi
s
Forc
e in
the
pulli
ng D
irect
ion
Forc
e in
the
rest
ing
Dire
ctio
ns
Pla
nar m
ovem
ent o
f T10
in th
e pu
lling
D
irect
ion
Qua
ntify
ing
Mul
ti-di
rect
iona
l Tru
nk S
tiffn
ess
Dur
ing
Sitti
ng w
ith a
nd w
ithou
t Fun
ctio
nal E
lect
rical
Stim
ulat
ion
A
ble-
Bod
ied
Indi
vidu
als
N W
u1,2
, M T
suki
mot
o1,3
, AH
Vet
te2,
4 , K
Mas
ani1 ,
MR
Pop
ovic
1,2
1 Ly
ndhu
rst C
entre
, Tor
onto
Reh
abili
tatio
n In
stitu
te, T
oron
to, C
AN
AD
A; 2
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring,
Uni
vers
ity o
f Tor
onto
, Tor
onto
, CA
NA
DA
3 D
epar
tmen
t of E
lect
rical
and
Com
pute
r Eng
inee
ring,
Uni
vers
ity o
f Tor
onto
, Tor
onto
, CA
NA
DA
; 4 D
epar
tmen
t of K
ines
iolo
gy, U
nive
rsity
of W
ater
loo,
Wat
erlo
o, C
AN
AD
A
Obj
ectiv
es
Syst
em Id
entif
icat
ion
Tech
niqu
e R
esul
ts
Reh
abili
tatio
n En
gine
erin
g La
bora
tory
C
onta
ct: m
ilos.
popo
vic@
utor
onto
.ca
ww
w.to
ront
o-fe
s.ca
Con
clus
ion
Bac
kgro
und
•In
abili
ty t
o vo
lunt
arily
con
trol
the
trunk
mus
cula
ture
for
ind
ivid
uals
with
sp
inal
cor
d in
jury
(S
CI)
caus
es b
oth
func
tiona
l pr
oble
ms
and
seco
ndar
y he
alth
com
plic
atio
ns.
•O
ne p
ossi
ble
solu
tion
to i
mpr
ove
sitti
ng b
alan
ce i
s to
use
a f
unct
iona
l el
ectri
cal s
timul
atio
n (F
ES
) to
activ
ate
patie
nt’s
ow
n m
uscu
latu
re to
sup
port
the
trunk
[1].
•To
bui
ld s
uch
FES
sys
tem
one
nee
ds to
det
erm
ine
mul
tidire
ctio
nal s
tiffn
ess
of t
he t
runk
dur
ing
sitti
ng a
nd t
o de
mon
stra
te t
hat
this
stif
fnes
s ca
n be
in
fluen
ced
by F
ES
.
Expe
rimen
t Su
bjec
ts:
•15
abl
e-bo
dy m
ale
subj
ects
with
ave
rage
s: 2
7yrs
, 176
cm a
nd 7
3kg
Task
: •
Sitt
ing
uprig
ht w
ith e
yes
clos
ed
•P
ertu
rbed
thro
ugh
a ch
est h
arne
ss in
8 h
oriz
onta
l dire
ctio
ns ra
ndom
ly
usin
g PA
PP
S, f
or a
tota
l of 1
60 tr
ials
[3]
•20
tria
ls fo
r eac
h pe
rturb
ed d
irect
ion:
10
with
out F
ES
and
10
with
FE
S
•FE
S a
pplie
d to
ere
ctor
spi
nae
& a
bdom
inal
mus
cles
in th
e lu
mba
r reg
ion
Mea
sure
men
ts:
•H
oriz
onta
l per
turb
atio
n fo
rce
•K
inem
atic
s of
T10
as
CO
M o
f tru
nk, u
sing
mot
ion
capt
ure
syst
em
Ana
lysi
s:
•Fi
rst 1
s tim
e pe
riod
from
the
onse
t of t
he p
ertu
rbat
ion
was
ana
lyze
d •
Trun
k w
as m
odel
led
as a
mas
s-sp
ring-
dam
per s
yste
m
•Tr
ansl
atio
nal a
nd to
rsio
nal t
runk
stif
fnes
s an
d da
mpi
ng w
ere
iden
tifie
d us
ing
an o
ptim
izat
ion
algo
rithm
(Mat
lab,
Mat
hwor
ks)
Part
ners
:
1.To
dev
elop
a n
ovel
pro
toco
l to
quan
tify
and
iden
tify
the
mul
tidire
ctio
nal s
tiffn
ess
of th
e tru
nk d
urin
g si
tting
2.
To te
st th
e ef
fect
of F
ES
on
the
mul
tidire
ctio
nal s
tiffn
ess
of th
e tru
nk.
- M
ultid
irect
iona
l stif
fnes
s of
the
trunk
is q
uant
ified
and
an
incr
ease
in
tran
slat
iona
l stif
fnes
s w
as s
how
n w
ith F
ES
con
ditio
n.
- Th
ese
resu
lts c
an b
e us
ed t
o de
velo
p an
FE
S p
roto
col
for
indi
vidu
als
with
SC
I to
impr
ove
thei
r sitt
ing
bala
nce
Exam
ple
of C
urve
Fitt
ing
to O
btai
n M
ass,
Stif
fnes
s, a
nd D
ampi
ng R
atio
Port
able
and
Aut
omat
ed P
ostu
ral
Pert
urba
tion
Syst
em (P
APP
S)
Loca
tions
of F
ES a
nd M
otio
n
Trac
king
Mod
el 1
) Tra
nsla
tiona
l Mas
s-Sp
ring-
Dam
per
CO
M –
cen
ter o
f mas
s of
the
syst
em
b –
dam
ping
coe
ffici
ent
k –
stiff
ness
coe
ffici
ent
F app
lied –
forc
e ex
erte
d on
the
CO
M
x –
disp
lace
men
t fro
m th
e eq
uilib
rium
pos
ition
Mod
el 2
) Tor
sion
al M
ass-
Sprin
g-D
ampe
r C
OM
– c
ente
r of m
ass
of th
e sy
stem
I –
mom
ent o
f ine
rtia
B –
tors
iona
l dam
ping
coe
ffici
ent
K –
tors
iona
l stif
fnes
s co
effic
ient
F a
pplie
d – fo
rce
exer
ted
on th
e C
OM
L
– le
ngth
from
L4/
L5 jo
int t
o th
e C
OM
g
– gr
avita
tiona
l con
stan
t –
ang
ular
dis
plac
emen
t fro
m th
e eq
uilib
rium
!""#
$%&
!!"#
$ !""#
$%&
!""#
$%&
rotoM gnitse
R dna gnilluP fo sevruC noitisoPEx
ampl
e: P
ositi
on a
nd F
orce
Pro
file
of a
Tria
l
#%!
&'((
)!*+
,!
#%!
&'((
)!-.! *+
,!
#%!
&'((
)!*+
,!
#%!
&'((
)!-.! *+
,!
#%!
&'((
)!*+
,!
#%!
&'((
)!-.! *+
,!
#%!
&'((
)!*+
,!
#%!
&'((
)!-.! *+
,!
~2.5
min
s
~30
min
s
2 m
ins
brea
k 2
min
s br
eak
2 m
ins
brea
k
Prot
ocol
of P
ertu
rbat
ion
Tim
elin
e
Tran
slat
iona
l Stif
fnes
s W
ith a
nd W
ithou
t FE
S - 2
Way
AN
OVA
: •
Mai
n Fa
ctor
: NO
FE
S v
s. F
ES
, p =
0.0
04
•M
ain
Fact
or: D
irect
ions
, p<0
.001
•
Inte
ract
ion:
p =
0.2
10
Tors
iona
l Stif
fnes
s W
ith a
nd W
ithou
t FE
S - 2
Way
AN
OVA
: •
Mai
n Fa
ctor
: NO
FE
S v
s. F
ES
, p =
0.1
16
•M
ain
Fact
or: D
irect
ions
, p<0
.001
•
Inte
ract
ion:
p =
0.1
97
-B
oth
trans
latio
nal a
nd to
rsio
nal s
tiffn
ess
are
sign
ifica
ntly
diff
eren
t bet
wee
n di
rect
ions
-
Tran
slat
iona
l stif
fnes
s is
sig
nific
antly
diff
eren
t bet
wee
n w
ith a
nd w
ithou
t FE
S
-To
rsio
nal s
tiffn
ess
is n
ot s
igni
fican
tly d
iffer
ent b
etw
een
with
and
with
out F
ES
Ref
eren
ces:
[1
] K. M
asan
i, et
al.
Clin
ical
Bio
mch
anic
s; 2
4:17
6-18
2, 2
009
[2] P
Lee
, et a
l. H
uman
Fac
tor;
49:1
00, 2
007
[3] A
H V
ette
, et a
l. A
SM
E J
. of M
edic
al D
evic
es; 2
: 200
8
PURPOSEPURPOSE
CONCLUSIONCONCLUSION
Center of Pressure Velocity Captures Body AccelerationRather Than Body Velocity During Quiet StandingMasani K 1, 2), Vette AH 1, 2), Abe MO 3), Nakazawa K 4), Popovic MR 1, 2)
1) Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, CANADA2) Lyndhurst Centre, Toronto Rehabilitation Institute, Toronto, CANADA 3) Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, JAPAN3) Department of Motor Dysfunction, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, JAPAN
To investigate the hypothesis that the fluctuation of COPv captures the fluctuation of ACC due to larger derivative gain in the neural control system during quiet standing
Joint World Congress of ISPGRand Gait & Mental Function
Trondheim, Norway, June 24–28, 2012e-mail : [email protected]
- The COP velocity fluctuation captures the COM acceleration fluctuation rather than the COM velocity fluctuation.
- The current results suggest that the neural motor command controlling quiet standing posture contains a significant portion that is proportional to the body velocity.
Partners:Rehabilitation Engineering Laboratory, Institute of Biomaterials and Biomedical Engineering, University of TorontoToronto Rehabilitation InstituteContact: [email protected] page: http://www.toronto-fes.ca
References[1] Peterka. J Neurophysiol 88:1097-118, 2002.[2] Masani K, et al. J Neurophysiol 100:1465-1475, 2008.[3] Masani K, et al. J Neurophysiol 90: 3774-3782, 2003.[4] Masani K, et al. Gait Posture 23:164-172, 2006.[5] Masani K, et al. Neurosci Lett 422: 202-206, 2007.
The views expressed in ths poster do not necessarily reflect those of any of the granting agencies.
The authors acknowledge the support of Toronto Rehabilitation Institute who receives funding under the Provincial Rehabilitation Research Program from the Ministry of Health and Long-Term Care in Ontario.
Subjects: - Young healthy subjects: n = 27 (female 14), 27.2±4.5 yrs- Elderly healthy subjects: n = 23 (female 12), 66.2±5.0 yrs
Task: - Quiet standing with eyes open for 90 sec on a force plate, 5 trials
Measurements:- Center of pressure (COP)- Sway at L5 using a laser displacement sensor- AP horizontal force
Analysis:- The body center of mass (COM) was estimated using the sway at L5.- The body acceleration was estimated using two ways: - AP horizontal force divided by the body mass (ACCf) - Second derivative of sway at L5 (ACCl)- All derivatives (COPv, COMv, ACCfv, ACClv) were also calculated.- To assess the amount of fluctuation, the root mean square (RMS) was calculated.
Experiment
BACKGROUNDBACKGROUND
Simulation
The center of pressure (COP) velocity (COPv) has been used as one of the most sensitive posturographic measures to detect changes in balance abilities due to aging and/or neurological diseases. Since the COP trajectory matches very well with the center of mass (COM) trajectory due to the body dynamics, the COP velocity has been believed to represent the COM velocity (COMv) in most of these studies. However, there is no study to date that has investigated the physical and physiological meaning of the COP velocity. Based on the motion equation of an inverted pendulum,
where ACC = body acceleration, I, m, h = body inertia, mass, and height, g = gravity coeff. According to this,
where ACCv = derivative of ACC (= jerk). Thus, COPv can be correlated with COMv. On the other hand, as COP = mg * TQ, where TQ = ankle torque, COP represents the ankle torque, which controls COM during queit standing. Based on the suggested models [1, 2], TQ may be modeled as,
where theta = body angle, and Kp, Kd, Ki, K, and B are controller gains (see below). Therefore,
Since it has been suggested that Kd is comparatively large in the control system [2, 3, 4], and considering ACC is similarly sensitive to COPv in detecting aging of postural control [5], Kd term may be dominant in dTQ, and as the result, dTQ and COPv are proportional to ACC.
++
KP
KD
+
NeuralController
+-+
K
B
MechanicalController
+
NMS
COP &Torque
COM &Angle
NMS (Neuro-musculo-skeletal system): 2nd order filter
Noise 1
KP
Noise 2 Noise 3
Model: - Neural Controller: 0<Kp<500, 0<Kd<300, 0<Ki<300- Motor delay = Sensory delay = 40 ms- Mechanical Controler: 0<K<1000, B=5- NMS: 0.1<1/omega<0.2 s- Time constant of Noise 1, 2: 5, 100, 200 s- Time constant of Noise 3: 0.025, 0.25, 0.5 s- Pendulum 1: H=0.852 m, W=580 N, I=44.9 kgm2
- Pendulum 2: H=0.986 m, W=957 N, I=85.7 kgm2
- Pendulum 3: H=0.773 m, W=394 N, I=24.7 kgm2
Stability: - Nyquist stability with gain (2dB) and phase (5 deg) margins
(eq 1)
(eq 2)
(eq 3)
(eq 4)
Examples of Recordings1
LaserDisplacementSensor
Force Plate
[cm]
-1
0
1
-1
0
1
-1.5
0
1.5
-6
0
6
-3
0
3
-1
0
1
-20
20
-150
0
150
0
2 s
[cm]
[cm/s2]
[cm/s2]
[cm/s]
[cm/s]
[cm/s3]
[cm/s3]
COP
ACCl
ACCf
COM
COPv
ACClv
ACCfv
COMv
Measurements Derivatives
- The COP, COM, COMv were not significantly different between the young and the elderly.- The ACC (ACCf and ACCl) and COPv were significantly different between the groups.
Differentiate
Simulation Study4
- In the simulation, the same results as the experiment, i.e., 1) COP and COM were highly correlated (A), 2) COPv and COMv were not very highly correlated (B), 3) COPv and ACC were highly correlated (C), were obtained.
0
0.2
0.4
0.6
0.8
1Contribution of Each Channelto Total dTQ
dKpdTQ
dKddTQ
dKidTQ
dKdTQ
dBdTQ
p < 0.0001
5 Nm
1 s
dTQ
dB Ch.
dK Ch.
dKi Ch.
dKd Ch.
dKp Ch.
0
0.005
0.01
0.015
0.02
0 0.005 0.01 0.015 0.02 0.025COP [m]
CO
M [m
]
0
0.005
0.01
0.015
0.02
0.025
0.03
0 0.01 0.02 0.03 0.04COPv [m]
CO
Mv
[m]
0
0.01
0.02
0.03
0.04
0.05
0 0.01 0.02 0.03 0.04COPv [m]
ACC
[m]
-2
0
2
4
6
8
10
0 5 10 15 20 25dTQ [Nm]
dKp
Ch.
[Nm
]
0
2
4
6
8
10
0 5 10 15 20 25dTQ [Nm]
dK C
h. [N
m]
0
0.05
0.1
0.15
0.2
0.25
0.3
0 5 10 15 20 25dTQ [Nm]
dB C
h. [N
m]
0
1
2
3
4
5
6
0 5 10 15 20 25dTQ [Nm]
dKi C
h. [N
m]
0
2
4
6
8
10
12
14
0 5 10 15 20 25dTQ [Nm]
dKd
Ch.
[Nm
]
A B C
++
KP
KD
+
NeuralController
+-+
K
B
MechanicalController
+
NMS
NMS (Neuro-musculo-skeletal system): 2nd order filter
Noise 1
KP
Noise 2 Noise 3
- The fluctuation of output from Kd channel was the largest among the terms in eq 4. This result suggests that Kd channel contributes to dTQ most compared to the other channels.
A B C D E
- Among the channels, Kd and B channels more correlated with dTQ compared to the other channels. Considering the contribution of B channel was very low, Kd channel must dominate the fluctuation of dTQ.
r = 0.952 r = 0.799 r = 0.985
r = 0.527 r = 0.397 r = 0.983r = 0.946 r = 0.751
- The COM and COP were highly correlated (A), agreeing with the motion equation (eq 1).- The COMv and COPv were correlated but not very strongly (B).- The ACC (ACCf and ACCl) were more strongly correlated with COPv (C and D), agreeing with our hypothesis.- While COMv and COPv were not highly correlated (B), ACCfv and COPv were very highly correlated (F) (Re:
ACCfv (E), see below). This suggests that among the terms in eq 2, ACCv term is dominant in determining COPv.
- The COP, COM and ACC satisfied eq 1 (A and B) suggesting that ACC is satisfactorily accurate.- However, only ACCf satisfied eq 2 (C and D). ACCl may contain a higher level of high frequency measurement errors.
0
0.2
0.4
0.6
0.8 COP[cm]
0
0.2
0.4
0.6
0.8
1 ACCf[cm/s2]
p < 0.0001
0
0.2
0.4
0.6
0.8 COM[cm]
0
0.5
1
1.5 COPv[cm/s]
p < 0.0001
0
0.1
0.2
0.3
0.4
0.5 COMv[cm/s]
0
0.5
1
1.5
2
2.5 ACCl[cm/s2]
p = 0.002
Young
Elderly
Amount of Fluctuation2
Correlations between Variables3
ACC
f [cm
/s2 ] C
COPv [cm/s]0.0 0.5 1.0 1.5 2.0
0.5
1.0
1.5
0.0
r = 0.900
2.0
4.0
6.0
8.0
10
0.0
COPv [cm/s]0.0 0.5 1.0 1.5 2.0
ACC
fv [c
m/s
3 ] F r = 0.951
COP [cm]
CO
M [c
m] A
0.0
0.5
1.0
1.5
2.0
0.0 0.5 1.0 1.5
r = 0.919
ACC
l [cm
/s2 ] D
COPv [cm/s]0.0 0.5 1.0 1.5 2.0
0.0
0.5
1.0
1.5
2.5
3.0
2.0
r = 0.838
10
20
30
40
50
0
COPv [cm/s]0.0 0.5 1.0 1.5 2.0
ACC
lv [c
m/s
3 ] E r = 0.606
COPv [cm/s]
CO
Mv
[cm
/s] B
0.0
0.1
0.2
0.3
0.5
0.6
0.4
0.0 0.5 1.0 1.5 2.0
r = 0.717
COP [cm]
CO
M+A
CC
f*I/m
gh [c
m]
A
0.0
0.5
1.0
1.5
0.0 0.5 1.0 1.5
2.0 r = 0.926
COP [cm]
CO
M+A
CC
l*I/m
gh [c
m]
B
0.0 0.5 1.0 1.50.0
0.5
1.0
1.5
2.0 r = 0.930
COPv [cm/s]CO
Mv+
dAC
Cf*I
/mgh
[cm
/s]
C
0.0 0.5 1.0 1.5 2.00.0
0.5
1.0
1.5
2.0 r = 0.945
COPv [cm/s]CO
Mv+
dAC
Cl*I
/mgh
[cm
/s]
D
0.0 0.5 1.0 1.5 2.00.0
1.0
2.0
3.0
4.0 r = 0.501
YoungElderly
- COPv correlated with ACCf more than with COMv, not only in RMS but also in other parameters quantifying fluctuations.
ACCl was Erroneous4
PURPOSEPURPOSE
CONCLUSIONCONCLUSION
Decomposing the Ankle Torque during Quiet Standing intoActive and Passive Components using EMG
Masani K 1, 2), Vette AH 1, 2), Abe MO 3), Nakazawa K 4), Popovic MR 1, 2)
1) Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, CANADA2) Lyndhurst Centre, Toronto Rehabilitation Institute, Toronto, CANADA 3) Department of Biology, Northeastern University, Boston, USA4) Department of Life Science, University of Tokyo, Tokyo, JAPAN
The purpose of this study was to validate the methodology that we recently proposed, via a systematic simulation study.
ISEK 2010Aalborg, Denmark, June 16-20, 2010
e-mail : [email protected]
- The decomposition method detected K and omega used in the simulations with a sufficiently small error, suggesting that the decomposition method is valid and practically feasible.
Partners:Rehabilitation Engineering Laboratory, Institute of Biomaterials and Biomedical Engineering, University of TorontoToronto Rehabilitation InstituteContact: [email protected] page: http://www.toronto-fes.ca
Passive and Active Torque Decomposition Process (Vette et al. 2010)
BACKGROUNDBACKGROUND
References[1] Casadio et al. Gait Posture 21: 410-424, 2005.[2] Loram et al. J Physiol 545: 1041-1053, 2002.[3] Vette et al. IEEE TNSRE 18(1): 86-95, 2008.[4] Conforto et al. Gait Posture 14: 28-35, 2001.
In the control system of quiet standing, the ankle torque generation is critical. The controlled ankle torque can be divided into 2 components: a passive torque component and an active torque component. The passive torque component is generated by the stiffness of the activated muscles, ligaments, and joint structures. The active torque component is generated by the muscle contractile elements, and is neurally controlled moment-to-moment. The passive component during quiet standing has been investigated by applying a quick perturbation at the ankle joint when subjects kept a standing posture. The identified stiffness in such perturbation experiments is about 70 to 90% of the required stiffness (Loram et al. 2002; Casadio et al. 2005). However, it is not certain that the stiffness actually contributes this much to the exerted ankle torque during quiet standing. In our recent study, we introduced a methodology decomposing the ankle torque during quiet standing into active and passive torque components using a simple model (Vette et al. 2010). However, internal noise properties in the control system may affect the outcomes of this approach. In this study, we investigated the practical feasibility of this methodology using a systematic simulation study.
Model (Vette et al. 2010)
The views expressed in ths poster do not necessarily reflect those of any of the granting agencies.
Brain Delay Muscle Body
AnkleStiffness
++
τ θ
NeuralController
+-
θ0 = 0+
K
B
MechanicalController
+
NMS
Physiological Control Scheme: Model for Optimization:
EMG Torque AngleMeasurements
Modeling
τ θ
NeuralController
K
B
MechanicalController
NMS
0
0.35
30
0.08
0.095
30
0
1
Young Elderly
ActTQ/ModelTQp = 0.003
0
1
Young Elderly
PassTQ/ModelTQp = 0.003
Tuned Parametersin the optimization analysis : Natural frequency G : Gain for NMS K : Intrinsic stiffness
0
1
Young Elderly
K/mghp = 0.029
- EMG was used as an input to the muscle model, and active torque was obtained as the output.- Body angle was used as an input to the mechanical controller, and passive torque was obtained as the output.
- Active and passive torque were added, and the model torque was obtained.- The model torque was fitted with the measured torque using the optimization technique.
- Ankle stiffness agreed with the previous study using a perturbation. The ankle stiffness was significantly smaller in the elderly than in the young.
- The contribution of passive torque was dominant in the model torque, and lower in the elderly than in the young.
- The elderly tend to have lower stiffness, and as such rely on the active torque more, which makes the elderly less stable.cf. 91±23 %
(Loram et al. 2002)
NMS (Neuro-musculo-skeletal system): 2nd order filter
EMG
ActiveTorque
Angle
PassiveTorque+ = Model
Torque
MeasuredTorque
Fitting usingOptimization
Gaussiannoise
+
++
PID- Kp- Kd- Ki
τ
θ
NeuralController
+
-
θ0 = 0+
K
B
MechanicalController
+
NMS
EMG
Torque
Angle
CNS
CNS
Decomposition Results
Validation of Decomposition Method using Simulation Study
- The fitting exhibited good results. The errors of the identified parameters were quite small, especially when the mechanical noise was not present.
- The decomposition method detected K and omega used in the simulations with a sufficiently small error, suggesting that the decomposition method is valid and practically feasible.
Driving Noise
- Postural sway during quiet standing was simulated, and the decomposition method was applied to the simulated time series.
- Mechanical noise simulated and slightly larger than the noise effect of hemodynamics described by Conforto et al. 2001, i.e., 0.4 N of the horizontal force.
0.075
0.1
-55
-30
-20
20
0 5 10 15 20 25 30
Angle
Simulated Torque
Muscle Activity Level
Time [s]
[rad]
[Nm
][a
.u.]
-55
-50
-45
-40
-35
0 5 10 15 20 25 30
-10
-5
Torq
ue [N
m]
Simulated Torque & Fitted Torque
Passive Torque
Active Torque
Examples of Application
012345
012345
012345
012345
12345
012345
Mean Amplitude of COP
Mean Amplitude of COP derivative“COP Velocity”
0
.5
1
0
.5
1
Young Elderly
[cm]
P = 0.141 P < 0.0001
Young Elderly
Young Elderly
SD of Total Torque[Nm]
SD of Active Torque SD of Passive Torque[Nm][Nm]
0
[cm/s] SD of dTotal Torque[Nm]
SD of dActive Torque SD of dPassive Torque[Nm][Nm]
Young Elderly
Young Elderly Young Elderly
Young ElderlyYoung Elderly
P = 0.336
P = 0.014 P = 0.617
P = 0.005
P = 0.0003 P = 0.840
- The difference of SD of active torque between the groups was detected by the COP Velocity and the derivative of total torque (B), while COP amplitude nor SD of total torque failed to detect the difference (A).
- The results suggest that the COP Velocity is a sensitive measure in detecting changes of active torque fluctuation induced by aging, since the contribution of active torque is larger in the torque derivative than in the torque itself.
0
500
0 500
0
500
6
12
6 12 0.6
1.2
0.6 1.2
0 500 6 12 0.6 1.26
12
0.6
1.2
Korg [Nm] ωn org [rad/s] G org
Korg [Nm] ωn org [rad/s] G org
Kopt
[Nm
]
ωn
opt [
rad/
s]
G o
pt
Kopt
[Nm
]
ωn
opt [
rad/
s]
G o
pt
Simulated SignalsDecomposition Outputs
Time [s]
Simulation Parameters:Kp = 200Kd = 200Ki = 200K = 400B = 5ωn = 8.33G = 1Gn1 = 200, τn1 = 80Gn2 = 0.025, τn2 = 1Gn3 = 1, τn3 = 80
With Mechanical Noise(Gn3=1)
Without Mechanical Noise(Gn3=0)
%error -0.13±0.30 % %error 0.24±0.54 % %error 0.46±1.23 %
%error 1.3±2.1 % %error 0.4±3.2 % %error -3.2±3.5 %
Simulation Parameters:Kp = 0 - 500 w step 200Kd = 0 - 300 w step 200Ki = 0 - 800 w step 200K = 0 - 500 w step 200B = 5ωn = 6.25 - 10G = 1(Gn1, τn1) = (5, 1) (100, 40) (200, 80)(Gn2, τn2) = (0.025, 1) (0.25, 40) (0.5, 80)Gn3 = 0, 1
Gaussiannoise
+
1
1
2
2
B.S.F- S.B.=0.1-1.5Hz- 8th BW- gain Gn3
Gaussiannoise
+
1) Why do the elderly sway larger? (SfN 2008)
2) Why is COP velocity sensitive to aging? (ISEK 2008)
A B
PURP
OSE
PURP
OSE
CO
NC
LUSI
ON
CO
NC
LUSI
ON
Cont
rolli
ng B
alanc
e dur
ing Q
uiet
Stan
ding
via C
o-Co
ntra
ction
in th
e Eld
erly
May
Not
Be A
dvan
tage
ous
To c
ompa
re p
ostu
ral s
way
dur
ing
the
perio
ds w
ith a
nd w
ithou
t the
co-
cont
ract
ion
betw
een
plan
tarfl
exor
s an
d do
rsifl
exor
, to
inve
stig
ate
the
role
of t
he c
o-co
ntra
ctio
n fre
quen
tly o
bser
ved
in th
e el
derly
dur
ing
quie
t sta
ndin
g
- Th
e co
-con
tract
ion
frequ
ently
obs
erve
d du
ring
quie
t st
andi
ng i
n th
e el
derly
doe
s no
t su
cces
sful
ly p
recl
ude
the
incr
ease
d po
stur
al s
way
. Rat
her,
the
co-c
ontra
ctio
n in
duce
s fu
rther
po
stur
al s
way
pro
babl
y du
e to
the
incr
emen
t of c
ontro
lling
para
met
ers.
- Th
e el
derly
sho
w th
e co
-con
tract
ion
as c
ompe
nsat
ing
reac
tions
rat
her
than
to r
educ
e th
e po
stur
al s
way
.
Partn
ers:
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
y,
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
Toro
nto
Reh
abili
tatio
n In
stitu
teC
onta
ct: k
.mas
ani@
utor
onto
.ca
web
pag
e: h
ttp:
//ww
w.to
ront
o-fe
s.ca
Subj
ects
: - Y
oung
hea
lthy
subj
ects
: n =
27
(14
fem
ales
), 27
,2±4
.5 y
rs- E
lder
ly h
ealth
y su
bjec
ts: n
= 2
3 (1
2 fe
mal
es),
66.2
±5.0
yrs
Task
: - Q
uiet
sta
ndin
g w
ith e
yes
open
for 9
0 se
c on
a fo
rce
plat
e, 5
tria
ls- S
ittin
g re
st fo
r 30
sec
Mea
sure
men
ts:
- Cen
ter o
f pre
ssur
e (C
OP)
- AP
horiz
onta
l for
ce- E
MG
s fo
r sol
eus
(SO
L), m
edia
l hea
d of
gas
trocn
emiu
s (M
G) a
nd ti
bial
is a
nter
ior (
TA)
Ana
lysi
s:- T
he b
ody
cene
r of m
ass
(CO
M) a
nd it
s ve
loci
ty (C
OM
v) w
ere
estim
ated
usi
ng G
ravi
ty L
ine
Proj
ectio
n M
etho
d (Z
atsi
orsk
y et
al.
1998
).- T
he v
eloc
ity o
f CO
P (C
OPv
) was
als
o ca
lcul
ated
.- T
he b
ody
acce
lera
tion
(AC
C) w
as e
stim
ated
by
divi
ding
the
AP h
oriz
onta
l for
ce b
y th
e bo
dy m
ass.
- Afte
r low
-pas
s fil
terin
g EM
Gs
with
a c
utof
f fre
quen
cy o
f 1 H
z, p
erio
ds w
hen
TA w
as a
ctiv
e (T
A-on
) and
inac
tive
(TA-
off)
wer
e id
entif
ied.
- To
iden
fity
thes
e pe
riods
, we
used
sev
eral
thre
shol
ds b
ased
on
TA a
ctiv
ity d
urin
g si
tting
re
st. T
he th
resh
olds
wer
e th
e av
erag
e of
sitt
ing
rest
+ 3
, 5, 7
, 9, 1
1 ×
SD. I
n th
is p
oste
r, w
e sh
owed
the
resu
lts w
ith s
ittin
g re
st +
3 ×
SD
in m
ost c
ases
.- T
he a
mou
nt o
f pos
tura
l sw
ay a
nd m
uscl
e ac
tiviti
es w
ere
dete
rmin
ed fo
r TA-
on/o
ff us
ing
the
stan
dard
dev
iatio
n du
ring
each
per
iod.
Expe
rimen
t
BA
CK
GR
OU
ND
BA
CK
GR
OU
ND
The
view
s exp
ress
ed in
ths p
oste
r do
not n
eces
saril
y re
flect
thos
e of
any
of t
he g
rant
ing
agen
cies
.
The
auth
ors a
ckno
wle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he P
rovi
ncia
l Reh
abili
tatio
n R
esea
rch
Prog
ram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io.
Exam
ples
of R
ecor
ding
s1
Effe
ct o
f Non
stat
iona
rity
5
Ref
eren
ces
[1] L
augh
ton
CA,
et a
l. Ag
ing,
mus
cle
activ
ity, a
nd b
alan
ce c
ontro
l: ph
ysio
logi
c ch
ange
s as
soci
ated
with
bal
ance
impa
irmen
t. G
ait P
ostu
re 1
8(2)
: 101
–108
, 200
3.[2
] Pan
zer V
P, B
andi
nelli
S, H
alle
tt M
. Bio
mec
hani
cal a
sses
smen
t of q
uiet
sta
ndin
g an
d ch
ange
s as
soci
ated
with
agi
ng. A
rch
Phys
Med
Reh
abil
76: 1
51–1
57, 1
995.
[3] Z
atsi
orsk
y VM
, Kin
g D
L. A
n al
gorit
hm fo
r det
erm
inin
g gr
avity
line
loca
tion
from
pos
turo
grap
hic
reco
rdin
gs. J
Bio
mec
h 31
: 161
–164
, 199
8.
Mas
ani K
1,2)
, Say
enko
DG
1,2)
, Jon
es M
1), A
be M
O 3
) , Nak
azaw
a K
4) , P
opov
ic M
R1,
2)
1) In
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eeri
ng, U
nive
rsity
of T
oron
to, T
oron
to, C
ANAD
A2)
Lyn
dhur
st C
entr
e, T
oron
to R
ehab
ilita
tion
Inst
itute
, Tor
onto
, CAN
ADA
3) R
esea
rch
Cent
er fo
r Adv
ance
d Sc
ienc
e an
d Te
chno
logy
, Uni
vers
ity o
f Tok
yo, T
okyo
, JAP
AN3)
Dep
artm
ent o
f Life
Sci
ence
s, U
nive
rsity
of T
okyo
, Tok
yo, J
APAN
Neur
osci
ence
201
1W
ashi
ngto
n DC
, Nov
12-
16, 2
011
e-m
ail :
k.m
asan
i@ut
oron
to.c
a
In
the
rese
arch
fiel
d of
hum
an b
iped
al s
tanc
e, m
any
stud
ies
have
focu
sed
on th
e co
ntro
l mec
hani
sm o
f the
ank
le
join
t tor
que
durin
g qu
iet s
tand
ing,
sin
ce th
e an
kle
join
t has
the
prim
ary
role
of m
aint
aini
ng c
ente
r of m
ass
(CO
M)
equi
libriu
m d
urin
g st
andi
ng. D
ue to
the
fact
that
the
CO
M is
in fr
ont o
f the
ank
le jo
int d
urin
g th
e na
tura
l sta
ndin
g po
stur
e, a
gra
vity
-indu
ced
torq
ue c
ontin
uous
ly a
ccel
erat
es th
e bo
dy fo
rwar
d fro
m th
e up
right
pos
ition
. The
refo
re, a
co
rrect
ive
ankl
e ex
tens
ion
torq
ue is
con
tinuo
usly
req
uire
d to
res
ist t
he g
ravi
ty e
ffect
and
to e
nsur
e th
at th
e C
OM
re
mai
ns c
lose
to th
e eq
uilib
rium
pos
ition
.
The
ankl
e ex
tens
ors
are
resp
onsi
ble
for
gene
ratin
g th
e co
rrect
ive
ankl
e ex
tens
ion
torq
ue,
sinc
e th
e an
kle
exte
nsor
s sh
ow c
ontin
uous
act
ivity
whe
reas
the
ankl
e fle
xors
are
sile
nt o
r onl
y in
term
itten
tly a
ctiv
e in
mos
t of c
ases
. H
owev
er, i
t has
bee
n re
porte
d th
at th
e el
derly
use
tibi
alis
ant
erio
r (TA
) for
long
er d
urat
ion
and
with
larg
er a
mou
nt
durin
g qu
iet s
tand
ing,
com
pare
d to
the
youn
g (L
augh
ton
et a
l., 2
003;
Pan
zer e
t al.,
199
5). A
s th
e pl
anta
rflex
ors
are
alw
ays
activ
e, th
e an
kle
join
t is
stab
ilized
by
co-c
ontra
ctin
g th
e pl
anta
rflex
ors
and
TA w
hen
TA is
act
ive.
It re
mai
ns
uncl
ear
if th
is c
o-co
ntra
ctio
n pr
eclu
des
grea
ter
post
ural
inst
abilit
y or
if it
is a
com
pens
ator
y re
spon
se t
o ot
her
fact
ors.
- The
re w
ere
sign
ifica
nt d
iffer
ence
s be
twee
n th
e gr
oups
and
bet
wee
n TA
-on
and
-off
as
wel
l as
the
inte
ract
ions
by
2-w
ay
RM
ANO
VA (p
< 0
.05)
, in
all m
easu
res
exce
pt fo
r the
diff
eren
ce b
etw
een
the
grou
ps fo
r CO
Mv
(p =
0.4
94).
- The
eld
erly
sho
wed
mor
e sw
ay o
n al
l po
stur
al s
way
mea
sure
s du
ring
TA-o
n,
whi
le th
e yo
ung
show
ed le
ss s
way
.
- For
mor
e st
atio
nary
mea
sure
s (C
OM
v, C
OPv
, and
AC
C),
ther
e is
a te
nden
cy th
at th
ey fl
uctu
ate
mor
e du
ring
TA-o
n in
bot
h gr
oups
, es
peci
ally,
for t
he s
ubje
cts
with
a la
rger
sw
ay.
- Thi
s re
sult
impl
ies
that
the
co-c
ontra
ctio
n of
the
ankl
e jo
int m
uscl
es in
crea
ses
the
post
ural
sw
ay m
ore
in c
ompa
rison
to th
e pl
anta
rflex
ors’
activ
ity a
lone
, whi
ch c
ould
be
a ca
use
of la
rger
pos
tura
l sw
ay in
the
elde
rly.
812.1
6
1 cm
10s
CO
M
2 cm
/s
ACC
CO
PV
CO
P
CO
Mv
1 cm
/s
1 cm
1 cm
/s2
2 μV
4 μV
2 μ
V
SOL
MG
TA
2 μV
1 μV
1 μV
Youn
gEl
derly
TA-o
nTA
-off
020406080100
%Period of TA-on
3SD
Youn
gEl
derly
5SD
7SD
9SD
11SD
- The
pos
tura
l sw
ay w
as la
rger
in th
e el
derly
com
pare
d to
the
youn
g.- T
he p
erio
ds fo
r TA-
on/o
ff w
ere
iden
tifie
d an
d th
e flu
ctua
tions
of t
he
post
ural
sw
ay a
nd m
uscl
e ac
tiviti
es w
ere
quan
tifie
d.
- The
eld
erly
sho
wed
long
er a
ctiv
ity in
TA
irres
pect
ive
of
the
type
of a
ctiv
ity id
entif
icat
ion
thre
shol
d us
ed.
- TA-
on p
erio
d w
as a
ppro
xim
atel
y 80
-90
% (M
edia
n) in
th
e el
derly
, and
app
roxi
mat
ely
10-2
0 %
in th
e yo
ung.
0.1
cm
1.0
s
TA o
nSD
= 0
.278
TA o
nSD
= 0
.380
CO
P
TA o
nSD
= 0
.808
ACC
TA o
nSD
= 0
.894
5.0
s
0.1
cm
Tim
e Sc
ale
I
ncre
ases
...
Varia
nce
D
ecre
ases
Tim
e Sc
ale
I
ncre
ases
...
Varia
nce
Eq
uiva
lent
!!0.
1 cm
1.0
s5.
0 s
0.1
cm
- The
CO
M a
nd C
OP
have
an
inhe
rent
cha
ract
eris
tic,
i.e.,
it sh
ows
larg
er v
aria
nce
with
long
er d
urat
ion
(not
sta
tiona
ry fo
r a s
hort
dura
tion)
.- T
here
fore
, thi
s re
sult
may
dep
end
on th
e di
ffere
nt
tota
l dur
atio
ns b
etw
een
TA-o
n an
d TA
-off.
- Unl
ike
CO
Mv,
CO
Pv a
nd A
CC
are
mor
e st
atio
nary
.
Dur
atio
ns o
f TA
-on/
-off
2
Post
ural
Sw
ay d
urin
g TA
-on/
off
3
Mus
cle
Act
ivity
dur
ing
TA-o
n/-o
ff4
- For
SO
L an
d M
G, t
here
wer
e si
gnifi
cant
inte
ract
ions
by
2-w
ay R
MAN
OVA
(p <
0.0
5) ,
whi
le th
ere
wer
e no
sig
nific
ant m
ain
effe
cts.
Fo
r TA,
ther
e w
as a
sig
nific
ant d
iffer
ence
bet
wee
n TA
-on
and
-off.
- Lar
ger f
luct
uatio
ns d
urin
g TA
-on
for t
he e
lder
ly s
ugge
st th
at th
e ad
ditio
nal a
ctiv
ity in
the
TA m
ay in
duce
incr
ease
d ac
tivity
in th
e pl
anta
rflex
ors
rela
ted
to p
ostu
ral c
orre
ctio
ns.
Com
paris
on o
f Pos
tura
l Sw
ay b
etw
een
TA-o
n an
d -o
ff6
00.2
0.4
0.6
CO
M[c
m]
Youn
gEl
derly
0
0.2
0.4
0.6
CO
P[c
m]
Youn
gEl
derly
0
0.1
0.2
0.3
CO
Mv
[cm
/s]
Youn
gEl
derly
0
0.5
1.0
1.5
CO
Pv[c
m/s
]
Youn
gEl
derly
0
0.2
0.4
0.6
0.8
1.0
ACC
[cm
/s2 ]
Youn
gEl
derly
0
0.00
05
0.00
1
0.00
15
0.00
2
0.00
25
0.00
3SO
L
0
0.00
1
0.00
2
0.00
3
0.00
4
0.00
5M
G
0
0.00
2
0.00
4
0.00
6TA* T
he b
ars
indi
cate
sta
tistic
al s
igni
fican
ces
by B
onfe
rroni
test
s.
0
0.7
[cm
] 00.
7[c
m]
CO
M
TA-off
TA-o
n0
0.4
[cm
/s] 0
0.4
[cm
/s]
CO
Mv
TA-off
TA-o
n
CO
P
0
0.7
[cm
] 00.
7[c
m]
TA-off
TA-o
n
CO
Pv
0
2.0
[cm
/s] 0
2.0
[cm
/s]
TA-off
TA-o
n
ACC
0
1.2
[cm
/s2 ] 0
1.2
[cm
/s2 ]
TA-off
TA-o
n
TA-o
nTA
-ff
Youn
gEl
derly
Res
ting
Thre
shol
d =
Aver
age+
3SD
TA d
urin
g st
andi
ng
TA-o
n Pe
riods
TA-o
ff Pe
riods
Youn
gEl
derly
Youn
gEl
derly
Youn
gEl
derly
[mV]
[mV]
[mV]
* The
bar
s in
dica
te s
tatis
tical
sig
nific
ance
s by
Bon
ferro
ni te
sts.
TA-o
nTA
-ff
Partners:
Natural Sciences and Engineering Research Council of Canada Conseil de recherches en sciences naturelles et en génie du Canada
The views expressed in this poster do not necessarily reflect those of any of the granting agencies.
Rehabilitation Engineering Laboratory Institute of Biomaterials and Biomedical Engineering, University of Toronto Toronto Rehabilitation Institute Contact: [email protected] www.toronto-fes.ca
Canadian Institutes of Health Research Instituts de rechere en santé du Canada
Ministry of Health and Long Term Care
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0 500 1000 1500 2000 2500
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4
Decrease in Venous Return due to Postural Change is Mitigated by Functional Electrical Stimulation for People with Spinal Cord Injury
T. Yoshida1,2, K. Masani2, D. G. Sayenko1,2, M. Miyatani2, J. A. Fisher3,4, and M. R. Popovic1,2
1 Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, CANADA 2 Rehabilitation Engineering Laboratory, Toronto Rehabilitation Institute, Toronto, CANADA 3 Department of Anaesthesia, University of Toronto, Toronto, CANADA 4 Division of Clinical Investigation and Human Physiology, Toronto General Research Institute, Toronto, CANADA
INTRODUCTION 1) Orthostatic hypotension (OH) is caused by gravitational venous pooling and a
subsequent decrease of the circulating blood volume. 2) OH can induce symptoms of cerebral hypoperfusion (e.g., headache,
lightheadedness, and dizziness), which can disable people from withstanding sitting or standing.
3) People with spinal cord injury (SCI) are susceptible to OH because of their impaired sympathetic cardiovascular control.
4) Functional electrical stimulation (FES) generates dynamic muscle contractions that mimic the skeletal muscle pump.
5) Cyclic passive leg movements can increase stroke volume in people with SCI.
PURPOSE To examine the effects of FES and passive stepping on the cardiovascular response of people with SCI under orthostatic stress. HYPOTHESES 1) FES and passive stepping should independently
induce venous return and mitigate a decrease in arterial pressure.
2) FES with passive stepping should be more effective than FES or passive stepping alone.
Experimental Conditions:
Sustained 70-degree head-up tilt
Passive stepping at 40 steps per minute
Bilateral FES of tibialis anterior, hamstring, quadriceps femoris, and triceps surae muscle
* HUT
STEP
= Tilt
Tilt + Stepping
IFES Tilt FES
DFES
=
= +
Tilt + Stepping = FES +
MATERIALS AND METHODS
Measurements:
Ultrasonography of the inferior vena cava in the transverse plane
Continuous beat-to-beat cardiovascular response Electromyographic (EMG) signals of medial gastrocnemius, tibialis anterior, biceps femoris, and rectus femoris
Participants: •10 participants (6 males) •43.5±10.8 years old, 172±11 cm, and 87.0±20.6 kg
Task Rest HUT Rest STEP Rest IFES Rest DFES
Position Supine Tilted Supine Tilted Supine Tilted Supine Tilted
Duration [Minutes] 10 10 10 10 10 10 10 10
The order of these conditions was randomized for each participant. Protocol:
•SCI at or above T6 level (T6 to C4) •9.90±8.56 years post injury •AIS: 5 A, 3 B, 1 C, and 1 D
CONCLUSIONS 1) FES was more effective than passive stepping in maintaining
stroke volume (SV). 2) FES and passive stepping maintained SV probably by inducing
venous return, as indicated by SBP. 3) FES and passive stepping did not interact synergistically.
ACKNOWLEDGMENT Authors thank Diane Kostka for analyzing the ultrasound images. This study was funded by the Natural Sciences and Engineering Research Council of Canada (Grant #249669), the Toronto Rehabilitation Institute, Ontario Ministry of Health and Long-Term Care, and HOCOMA AG, which supported the EMG measurements and analysis pertinent to this study.
2 Change in Systolic Blood Pressure from Supine ( SBP) 1 Change in Stroke Volume from Supine
( SV)
Main Effects and Interactions 4
Cardiovascular Parameter
FES Passive Stepping
FES Passive Stepping
F(1,9) p F(1,9) p F(1,9) p SV 15.6 0.003* 2.35 0.159 1.31 0.282
SBP 14.3 0.004* 10.9 0.009* 0.542 0.480 HR 7.07 0.026* 0.089 0.772 2.34 0.161
RESULTS
STEP IFES DFES = = =
3 Change in Heart Rate from Supine ( HR)
The work presented in this poster is under review for publication as “Cardiovascular Response of Individuals with Spinal Cord Injury to Dynamic Functional Electrical Stimulation under Orthostatic Stress” in IEEE Transactions on Neural Systems and Rehabilitation Engineering (submitted Nov. 15, 2011).
* Tilt Stepping FES
HUT =
Dat
a C
olle
ctio
n:
Stan
dard
Mea
sure
s •
cfP
WV
(See
cfP
WV
mea
sure
men
ts s
ectio
n)
• A
erob
ic c
apac
ity: V
O2p
eak
(Arm
erg
omet
ry, W
ork
rate
: inc
reas
ed a
t 30
kpm
/min
or 6
0 kp
m/
min
at
one
min
ute
inte
rval
s)
• S
mok
ing
stat
us
• M
etab
olic
syn
drom
e:
Pre
sent
ing
any
thre
e of
the
follo
win
g fiv
e ris
k fa
ctor
s: 1
) ele
vate
d w
aist
circ
umfe
renc
e:
102c
m in
m
ales
, 88
cm in
fem
ales
; 2) e
leva
ted
trigl
ycer
ides
: 1.
70 m
mol
/L o
r dru
g tre
atm
ent f
or e
leva
ted
trig
lyce
rides
; 3) r
educ
ed H
DL-
C: <
1.03
mm
ol/L
in m
ales
, <1.
32 m
mol
/L
in fe
mal
es o
r dru
g t
reat
men
t for
redu
ced
HD
L-C
; 4) e
leva
ted
bloo
d pr
essu
re: S
BP
130m
mH
g or
DB
P 85
mm
Hg
or a
ntih
yper
tens
ive
drug
trea
tmen
t; 5)
ele
vate
d fa
stin
g gl
ucos
e 5.
6mm
ol/L
or d
rug
treat
men
t for
ele
vate
d gl
ucos
e (d
efin
ed in
acc
orda
nce
with
Nat
iona
l Hea
rt,
Lung
, and
Blo
od In
stitu
te/A
mer
ican
Hea
rt A
ssoc
iatio
n)
SCI S
peci
fic M
easu
res
• D
urat
ion
of in
jury
(yea
rs)
• A
ge a
t inj
ury
(yea
rs)
• N
euro
logi
c Le
vel o
f Inj
ury
(NLI
: abo
veT1
: Tet
rapl
egia
, bel
ow T
1: P
arap
legi
a)
• A
SIA
Impa
irmen
t Sca
le (A
IS)
The
Ass
ocia
tions
Bet
wee
n A
erob
ic C
apac
ity a
nd A
rter
ial S
tiffn
ess
in P
eopl
e w
ith C
hron
ic S
pina
l Cor
d In
jury
M
Miy
atan
i1 , C
Moo
re1,
2, K
. Mas
ani1 ,
PI O
h3,4
, MR
Pop
ovic
1,5 ,
and
BC
Cra
ven
1,4
1 Tor
onto
Reh
abili
tatio
n In
stitu
te, S
pina
l Cor
d R
ehab
Pro
gram
; 2D
epar
tmen
t of K
ines
iolo
gy, U
nive
rsity
of W
ater
loo;
3To
ront
o R
ehab
ilita
tion
Inst
itute
, Car
diac
Reh
abili
tatio
n an
d S
econ
dary
Pre
vent
ion
Pro
gram
, 4 D
epar
tmen
t of M
edic
ine,
Uni
vers
ity o
f Tor
onto
, 5In
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eerin
g, U
nive
rsity
of T
oron
to;
Obj
ectiv
e To
exp
lore
the
asso
ciat
ions
bet
wee
n ae
robi
c ca
paci
ty (V
o 2pe
ak) a
nd th
e di
agno
stic
thre
shol
d fo
r su
bclin
ical
vas
cula
r end
-org
an d
amag
e (d
efin
ed b
y cf
PW
V v
alue
s 12
00 c
m/s
)[1] a
mon
g ad
ults
w
ith c
hron
ic S
CI.
Ack
now
ledg
emen
ts
Ont
ario
Neu
rotra
uma
Foun
datio
n (O
NF)
Gra
nt #
:200
8-S
CI-P
DF-
692
The
auth
ors
ackn
owle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he
Pro
vinc
ial R
ehab
ilita
tion
Res
earc
h P
rogr
am fr
om th
e M
inis
try o
f Hea
lth a
nd L
ong-
Term
Car
e in
Ont
ario
. R
esul
ts
Met
hods
A
bstr
act
Peo
ple
livin
g w
ith s
pina
l cor
d in
jury
(S
CI)
are
a vu
lner
able
pop
ulat
ion
pron
e to
cor
onar
y ar
tery
di
seas
e (C
AD
) re
sulti
ng i
n hi
gh m
orbi
dity
and
mor
talit
y. A
rteria
l st
iffne
ss a
sses
sed
by p
ulse
w
ave
velo
city
mea
sure
d be
twee
n th
e co
mm
on c
arot
id a
nd f
emor
al a
rterie
s (c
fPW
V)
is a
n es
tabl
ishe
d in
depe
nden
t pre
dict
or o
f CA
D m
orbi
dity
and
mor
talit
y in
the
able
-bod
ied
popu
latio
n.
The
Eur
opea
n S
ocie
ty o
f H
yper
tens
ion
and
the
Eur
opea
n S
ocie
ty o
f C
ardi
olog
y ha
ve d
efin
ed
cfP
WV
val
ues
1200
cm
/s a
s a
diag
nost
ic th
resh
old
for s
ubcl
inic
al v
ascu
lar e
nd-o
rgan
dam
age.
P
rior
stud
ies
have
dem
onst
rate
d th
at a
erob
ic c
apac
ity i
s in
vers
ely
asso
ciat
ed w
ith a
rteria
l st
iffne
ss in
abl
e-bo
died
peo
ple.
How
ever
, the
rel
atio
nshi
p be
twee
n ar
teria
l stif
fnes
s, p
artic
ular
ly
elev
ated
cfP
WV
val
ues
(12
00 c
m/s
), an
d ae
robi
c ca
paci
ty in
peo
ple
with
SC
I ha
s no
t be
en
desc
ribed
. O
bjec
tive:
To
expl
ore
the
asso
ciat
ions
bet
wee
n ae
robi
c ca
paci
ty (
Vo2p
eak)
and
ele
vate
d cf
PW
V v
alue
s (
1200
cm
/s) a
mon
g ad
ults
with
chr
onic
SC
I. M
etho
ds: F
orty
-one
men
and
wom
en w
ith c
hron
ic S
CI (
C2-
T12;
AIS
A-D
; 24
para
pleg
ics
and
17
tetra
pleg
ics;
tim
e po
st in
jury
: 14
.7±1
1.4
yrs;
Age
: 49
.4 ±
13.1
yrs
; H
eigh
t: 17
3.2
± 9.
8cm
; an
d W
eigh
t: 81
.7 ±
17.
6 kg
) pa
rtici
pate
d in
the
stu
dy.
cfP
WV
was
mea
sure
d us
ing
two
Dop
pler
flo
wm
eter
s an
d Vo
2pea
k w
as m
easu
red
by a
rm e
rgom
eter
y. S
ubje
cts
wer
e st
ratif
ied
into
tw
o gr
oups
acc
ordi
ng t
o cf
PW
V v
alue
s (<
1200
cm
/sec
: lo
w c
fPW
V,
1200
cm
/sec
: hi
gh c
fPW
V).
Logi
stic
reg
ress
ion
anal
ysis
was
use
d to
det
erm
ine
the
cont
ribut
ion
of a
erob
ic c
apac
ity a
fter
adju
stm
ent f
or c
onfo
unde
rs (
age,
gen
der,
met
abol
ic s
yndr
ome,
sm
okin
g st
atus
, Neu
rolo
gicl
evel
of
inju
ry (N
LI),
and
AS
IA Im
pairm
ent S
cale
(AIS
) to
Hig
h cf
PW
V. R
esul
ts: A
erob
ic c
apac
ity w
as
sign
ifica
ntly
and
neg
ativ
ely
asso
ciat
ed w
ith c
fPW
V a
fter
adju
stm
ents
with
oth
er r
isk
fact
ors
(r=-
0.38
5, p
<0.0
45).
Afte
r cor
rect
ion
for o
ther
con
foun
ding
par
amet
ers,
aer
obic
cap
acity
was
an
inde
pend
ent
pred
icto
r fo
r hi
gh c
fPW
V (
odds
rat
io =
2.2
0, 9
5% C
I=1.
06–
4.59
, p<
0.03
4).
Con
clus
ion:
Aer
obic
cap
acity
is a
n in
depe
nden
t pre
dict
or o
f hig
h cf
PW
V v
alue
s (
1200
cm
/sec
) am
ong
peop
le w
ith c
hron
ic S
CI.
Furth
er re
sear
ch is
nee
ded
to e
xplo
re w
heth
er im
prov
emen
ts in
ae
robi
c ca
paci
ty w
ill re
duce
arte
rial s
tiffn
ess
and
adve
rse
card
iac
outc
omes
am
ong
peop
le w
ith
chro
nic
SC
I.
r=-0
.515
(p<0
.05)
0
500
1000
1500
2000
2500
0 10
20
30
40
cfPWV (cm/sec)
Vo2p
eak
(ml/k
g/m
in)
Men
Wom
en
cfPW
V vs
. Vo 2
peak
cfP
WV
was
sig
nific
antly
cor
rela
ted
with
Vo 2
peak
. Thi
s re
mai
ned
sign
ifica
nt a
fter c
orre
ctin
g fo
r age
, gen
der,
NIL
(tet
rapl
egia
or p
arap
legi
a), A
IS (A
,B,C
or D
) and
met
abol
ic s
yndr
ome
(p
artia
l r=0
.385
, p<
0.05
).
Adj
uste
d R
elat
ive
Ris
k (R
R) f
or H
igh
cfPW
V by
Vo 2
peak
Acc
ordi
ng to
the
logi
stic
regr
essi
on a
naly
sis,
afte
r con
trolli
ng a
ge, g
ende
r, m
etab
olic
syn
drom
e,
smok
ing,
NLI
and
AIS
, Vo 2
peak
was
a s
igni
fican
t pre
dict
or o
f the
pre
senc
e of
hig
h cf
PW
V c
fPW
V
(RR
= 2
.20,
95%
CI=
1.06
– 4.
59, p
<0.0
34).
Con
clus
ions
A
erob
ic c
apac
ity is
an
inde
pend
ent p
redi
ctor
of h
igh
cfP
WV
val
ues
(12
00 c
m/s
ec)
amon
g pe
ople
w
ith c
hron
ic S
CI.
Furth
er re
sear
ch is
nee
ded
to e
xplo
re w
heth
er im
prov
emen
ts in
aer
obic
cap
acity
w
ill re
duce
arte
rial s
tiffn
ess
and
adve
rse
card
iac
outc
omes
am
ong
peop
le w
ith c
hron
ic S
CI.
Part
icip
ants
:
Ref
eren
ces
[1] M
anci
a G
, De
Bac
ker G
, Dom
inic
zak
A, C
ifkov
a R
, Fag
ard
R, G
erm
ano
G, G
rass
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Partners:
Canadian Institutes of Health Research Instituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of Canada Conseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health and Long Term Care
The views expressed in this poster do not necessarily reflect those of any of the granting agencies.
Rehabilitation Engineering Laboratory Institute of Biomaterials and Biomedical Engineering, University of Toronto Toronto Rehabilitation Institute Contact: [email protected] www.toronto-fes.ca
EMG-onset Detection using Change-point Analysis Lev Vaismana,b, Jose Zariffaa,b,c, Kei Masania,b, Milos R. Popovica,b,c
a Institute of Biomaterials and Biomedical Engineering, University of Toronto, b Rehabilitation Engineering Laboratory, Toronto Rehabilitation Institute, c Edward S. Rogers Sr., Department of
Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada
Detecting onset of muscle contraction from an electromyography (EMG) signal recording is an important task for applications in neurology, psychophysiology and EMG-controlled neuroprosthetic devices development.
Introduction
Change-Point Detection Process
Change-point detection problem is to detect abrupt changes in statistical properties of a signal.
Results Sample successful EMG onset detection by change-point analysis for the wrist and trunk muscles are shown in Figure 1.
Figure 1: Sample results for onset detection in A) wrist muscle EMG, B) trunk muscle EMG. Circle marks detected onset
A B
Methods Overview
Conclusions and Future Work
Discussion
To evaluate the quality of the EMG onset estimates, the average absolute differences between the three visual estimates and each of the computer estimates were computed for all used EMG segments within datasets and compared using Kruskal–Wallis ANOVA with 5% significance level. Results in Figure 2.
The change-point detection algorithm can be applied directly to raw signal, automatically “denoises” the signal, and does not require a priori knowledge of signal properties.
The main drawback of change-point detection is that it cannot identify what all the detected changes are due to. For example, it cannot distinguish between the changes due to tremor and true muscle activation, or between multiple changes in the signal, which are not due to muscle activation (common in trunk EMG data), based on the magnitude of detection statistic only. Use of change duration in addition to detection statistic’s magnitude improves this ability.
The change-point analysis method can be used to detect muscle activation in EMG signals. An application to detection of bursts of intermittently active muscle within the recorded continuous activity of other muscles is currently investigated. Additional detection statistics processing to improve the performance is also investigated.
EMG onset is a change-point!
Muscle activation can represent such a change in EMG signal. We apply the change-point detection method [1] to EMG signals to investigate its usefulness for the detection of onset of muscle activity and compare its performance to other common onset detection approaches.
Three methods of onset detection used for comparison with change-point method were: (1) visual detection by three specialists in EMG processing, (2) Hodges and Bui threshold-based algorithm [2], and (3) Donoho’s wavelet-based denoising [3] followed by Hodges and Bui algorithm.
The EMG data was recorded from the extensor carpi radialis muscles, and from the muscles maintaining trunk stability when seating. Details in [4]
References
[1] Moskvina V, Zhigljavsky A. Commun Stat Simul Comput 2003;32(2):319–52. [2] Hodges PW, Bui BH. Electroen Clin Neurophysiol 1996;101:511–9. [3] Donoho DL. IEEE Trans Inform Theory 1995;41(3):613–27. [4] Vaisman L., Zariffa J., Popovic MR. Journal of Electromyography and Kinesiology 20 (2010) 750–760.
Figure 2: Median ranks of average absolute differences (smaller ranks -> better performance for 3 computer methods. Results shown for 9 wrist and 2 trunk EMG datasets .
Canadian Institutes of Health ResearchInstituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of CanadaConseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health and Long Term Care
Partners:
Proof-of-Concept StudyMaterials and Methods• 1 participant (male, able-bodied, age 24)• Measured typing speed and degree of control by asking the participant to type a sentence• Used WiViK on-screen keyboard (http://www.wivik.com/) with two different cursor control approaches:
(1) EGT-controlled cursor positioning and BCI-controlled mouse clicks (EGT-BCI system)
(2) EGT-controlled cursor positioning and “dwell time”- controlled mouse clicks (EGT system only)
Results• The EGT-BCI system resulted in a lower typing speed but allowed the participant a greater degree of control (assessed subjectively)
Rehabilitation Engineering LaboratoryInstitute of Biomaterials and Biomedical Engineering, University of TorontoToronto Rehabilitation InstituteContact: [email protected]
A Novel Assistive Device for Cursor ControlX. Zhao1, E.D. Guestrin2,3, C. Márquez-Chin2,3, S.C. McGie2,3, E. Sanin3,4, and M.R. Popovic2,3
A Combined Eye-Gaze Tracking and Brain-Computer Interface System
Fig. 1 – The input from the EGT and BCI are integrated to control a computer cursor.
1. Division of Engineering Science, University of Toronto; 2. Institute of Biomaterials & Biomedical Engineering, University of Toronto; 3. Toronto Rehabilitation Institute; 4. Department of Mechanical and Industrial Engineering,
University of Toronto
Fig. 2 – The participant controls the position of the cursor with his gaze and generates “click” commands by invoking motor imagery.
The EGT-BCI System• Eye-gaze tracking is the most efficient modality for cursor position control, but the use of “dwell time” to generate click commands can result in unintentional actions (this is known as the “Midas’ touch” problem)• A brain-computer interface may provide a solution to the “Midas’ touch” problem; it can also be used by severely disabled individuals
Eye-gaze tracker (EGT)• Captures images of the user’s eyes using a video camera and two near-infrared light sources• Uses a mathematical model and eye features extracted from the images to calculate the user’s point-of-gaze on a computer screen
Brain-computer interface (BCI)• Uses a surface electrode to receive EEG signals from the user’s left motor cortex• The user generates an “activation” event using motor imagery of the right hand
Eye-gaze tracker
Brain- computer interface
Data integration application
User display
TCP/IP
TCP/IP
Cursor position and click control
Fig. 3 – The participant typed a sentence using the EGT-BCI system, as well as the EGT system with 2 different dwell time settings.
Access modality Resolution Data transfer rate
Risk
Mechanical switch Low Low Low
EMG-based Medium Medium Low
Eye-gaze tracking High High Low
Non-invasive BCIs Low Low Low
Invasive BCIs High High High
BackgroundTarget Population• Severely motor impaired and nonverbal individuals with intact cognitive abilities (e.g., victims of severe spinal cord injury or advanced amyotrophic lateral sclerosis)
Table 1: Common Access Modalities
Canadian Institutes of Health Research
Instituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of Canada
Conseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health
and Long Term Care
Partners: Rehabilitation Engineering Laboratory
Institute of Biomaterials and Biomedical Engineering, University of Toronto
Toronto Rehabilitation Institute
Contact: [email protected]
www.toronto-fes.ca
Estimation of Arm Kinematics Using ECoG Recording O.Talakoub1,2, C. Marquez Chin2,3, R. Chen4,5, M. R. Popovic2,3, W. Wong1,2
][][][ jnxnxnRx
Brain–Computer Interfaces (BCIs) interpret brain activities to
user’s intent in order to control an external actuator or
computing device. Because these systems do not depend on
peripheral nerves and muscle activity, they can be used by
individuals with severe motor disabilities caused by
amyotrophic lateral sclerosis, brainstem stroke or other
neuromuscular diseases that make it impossible to move or to
express themselves.
A BCI system identifies and decodes the brain activity related
to the behavioural outcome. While BCI systems can be
implemented using virtually any type of brain activity, most
often they are implemented with electrical signals from the
brain. Electrophysiological (ECoG) signals have already
proven to be suitable for classification and decoding of a
limited set of discrete arm movements. However, real-life
applications often should consider continuous movements.
From a rehabilitation perspective, the ultimate goal is to be
able to offer a technological solution whereby disabled
individuals without the ability to move voluntarily can control
external devices using brain activity. Such an interface must
not only allow for high accuracy of control and a high
communication rate between user and device, but be
relatively non-invasive in its implementation.
In our simple prediction model, we hypothesize that Upper
limb position and velocity are encoded into the brain activity
and the functional relationship between ECoG recordings from
primary motor cortex and upper limb velocity is linear. Thus,
the dynamical behaviour of the arm can be predicted solely
from ECoG recordings from primary motor cortex.
Two important physiological characteristics of the motor
system are taken into consideration. The first is the delay
between the cortical activity and the corresponding motor
output. The lag represents a transmission delay between
cortical motoneuron spike response and emergence of
EMG/kinematic activity. We incorporate the delay into the
linear model as a fitting parameter. The second physiological
characteristic relates to event-related synchronization and
desynchronization in the beta and gamma frequency bands.
These events are used as indicators of movement initiation
and termination.
To evaluate the accuracy of the model, we estimated the arm
velocity of a single trial by using the remaining trials as a
training set. Training and test data were then permuted. The
average Pearson correlation between the estimated velocity
and actual limb velocity was 84%. Examples of the predicted
velocity profiles are illustrated in Figure (1).
Introduction and Method
Fig1 – Arm velocity predicted by described multi-linear
regression model from four ECoG electrodes is shown by solid
line while actual arm velocity is shown by dashed-lines. The
graphs show velocities on x-axis, y-axis, and z-axis,
respectively.
1Department of Electrical and Computer Engineering, University of Toronto 2Institute of Biomaterials and Biomedical Engineering, University of Toronto
3Rehabilitation Engineering Laboratory, Toronto Rehabilitation Institute 4Toronto Western Research Institute, University Health Network
5Division of Neurology, Department of Medicine, University of Toronto
Usin
g El
ectr
ocor
ticog
raph
icR
ecor
ding
s to
Estim
ate
Upp
er L
imb
Kin
emat
ics
Om
id T
alak
oub1,
2 , C
esar
Mar
quez
Chi
n2,3 ,
Rob
ert C
hen4,
5 , M
ilos R
. Pop
ovic
2,3 ,
and
Will
y W
ong1,
2
1 Dep
artm
ent o
f Ele
ctric
al a
nd C
ompu
ter E
ngin
eerin
g, U
nive
rsity
of T
oron
to
2 Ins
titut
e of
Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eerin
g, U
nive
rsity
of T
oron
to
3 Reh
abili
tatio
n En
gine
erin
g La
bora
tory
, Tor
onto
Reh
abili
tatio
n In
stitu
te
4 Tor
onto
Wes
tern
Res
earc
h In
stitu
te, U
nive
rsity
Hea
lth N
etw
ork
5 Div
isio
n of
Neu
rolo
gy, D
epar
tmen
t of M
edic
ine,
Uni
vers
ity o
f Tor
onto
Met
hod
Mat
eria
lA
73ye
arol
dm
ale
withParkinson’sd
isea
sean
da
65ye
arol
dfe
mal
ew
ithes
sent
ial
trem
or,
parti
cipa
ted
inth
isst
udy.
The
subj
ects
wer
ere
crui
ted
from
the
Mov
emen
tD
isor
ders
Clin
icof
the
Toro
nto
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tern
Hos
pita
l.Th
eyw
ere
med
icat
edat
the
time
ofte
stin
g.B
oth
parti
cipa
nts
rece
ived
asy
stem
for
dire
ctbr
ain
stim
ulat
ion
for
the
treat
men
tof
trem
or.
This
proc
edur
ebe
gan
with
the
impl
anta
tion
ofsu
bdur
alel
ectro
des.
The
uppe
rlim
bm
ovem
ent
was
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rded
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dim
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onal
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trom
agne
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cker
.A
sens
orw
aspl
aced
over
the
dors
alas
pect
ofth
eth
irdm
etac
arpa
lbo
ne.
The
posi
tion
ofth
ispo
int
inth
ree-
dim
ensi
ons
inad
ditio
nto
itsro
tatio
nw
asre
cord
edw
hile
the
parti
cipa
nts
wer
ere
achi
ngto
left,
reac
hing
torig
ht,o
rfle
the
wris
t.
00.
51
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0
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rofil
e
Neu
ral a
ctiv
ity sp
ectr
al w
arpi
ngTh
esp
ectra
lco
nten
tof
neur
alac
tivity
has
been
show
nto
bein
dica
tive
ofch
ange
sinuser’s
men
tal
stat
ean
din
tent
ion.
The
time
trans
form
atio
nm
apob
tain
byw
arpi
ngth
eki
nem
atic
sis
appl
ied
toth
esp
ectra
ldis
tribu
tion
ofth
eE
CoG
sign
al.T
head
vant
age
isth
atw
arpi
ngpr
eser
ves
the
spec
tralc
onte
ntof
the
sign
al.
Con
clus
ion
Volu
ntar
ilyse
lf-pa
ced
mov
emen
tsar
ein
cons
iste
ntin
time
dura
tion
and
spee
d.Th
us,
the
neur
alev
ent
shou
ldbe
tem
pora
llyal
igne
dfo
rco
mpa
rison
and
stat
istic
alan
alys
ispu
rpos
es.C
onsi
sten
tpa
ttern
sam
ong
the
trial
sar
eid
entif
ied
todi
stin
guis
hth
em
ovem
ent
and
deco
deth
ear
mki
nem
atic
para
met
ers
from
the
corti
cala
ctiv
ities
.
Ele
ctro
phys
iolo
gica
l(E
CoG
)si
gnal
sha
veal
read
ypr
oven
tobe
suita
ble
forc
lass
ifica
tion
and
deco
ding
ofa
limite
dse
tofd
iscr
ete
arm
mov
emen
ts.
How
ever
,re
al-li
feap
plic
atio
nsof
ten
shou
ldco
nsid
erco
ntin
uous
mov
emen
ts.
An
impo
rtant
chal
leng
eto
impl
emen
ta
cont
inuo
usm
ovem
ent
clas
sifie
ris
that
volu
ntar
yar
mm
ovem
ents
are
self-
pace
d(i.
e.,t
hey
can
occu
rata
nym
omen
t)an
d
Tim
e (s
)Ti
me
(s)
We
disc
over
edce
rtain
func
tiona
lre
latio
nshi
pbe
twee
nth
eco
rtica
lre
cord
ings
and
mot
ion
para
met
ers;
e.g.
posi
tion
and
velo
city
.O
urre
sult
show
edth
atth
eup
perl
imb
kine
mat
icpa
ram
eter
sca
nbe
estim
ated
usin
gon
lyE
CoG
reco
rdin
gsfro
mfo
urel
ectro
des
impl
ante
dov
erth
epr
imar
yco
rtex.
This
isw
hile
othe
rsys
tem
sus
ually
cons
ider
agr
idof
mor
eth
an64
elec
trode
sto
map
the
brai
nan
des
timat
eth
em
ovem
ent
kine
mat
icpa
ram
eter
s.U
sing
four
Back
grou
nd a
nd M
otiv
atio
n:U
nder
stan
ding
and
deco
ding
hum
anbe
havi
our
thro
ugh
elec
troph
ysio
logi
cal
mea
nsis
one
ofth
egr
eatc
halle
nges
ofm
oder
nsc
ienc
e.B
rain‒C
ompu
ter
Inte
rface
s(B
CIs
)in
terp
ret
brai
nac
tiviti
estouser’s
inte
ntin
orde
rto
cont
rol
anex
tern
alac
tuat
oror
com
putin
gde
vice
.B
ecau
seth
ese
syst
ems
d ono
tdep
end
onpe
riphe
raln
erve
san
dm
uscl
eac
tivity
,the
yca
nbe
used
byin
divi
dual
sw
ithse
vere
mot
ordi
sabi
litie
sca
used
byam
yotro
phic
late
ral
scle
rosi
s,br
ains
tem
stro
keor
othe
rne
urom
uscu
lar
dise
ases
that
mak
eit
impo
ssib
leto
mov
eor
toex
pres
sth
emse
lves
.
Acl
ass
ofB
CIs
yste
min
volv
esde
codi
ngm
otio
nki
nem
atic
sfro
mbr
ain
sign
als.
The
syst
emid
entif
ies
and
deco
des
the
brai
nac
tivity
rela
ted
toth
ebe
havi
oura
lou
tcom
e.
Neu
ral a
ctiv
ity te
mpo
ral a
lignm
ent
Ifth
em
ovem
ent
kine
mat
icis
lock
edto
the
neur
alac
tiviti
es,
reco
rded
brai
nac
tivity
can
bead
just
edfo
rtem
pora
lvar
iatio
nsin
trodu
ced
byho
wth
eta
skw
aspe
rform
ed.T
hetim
e-al
ignm
enti
sac
hiev
edby
elas
ticde
form
atio
nof
time.
The
Dyn
amic
Tim
eW
arpi
ng(D
TW)
algo
rithm
isex
trem
ely
effic
ient
asa
time-
serie
ssi
mila
rity
mea
sure
whi
chm
inim
izes
the
effe
cts
ofsh
iftin
gan
ddi
stor
tion
intim
eby
allo
win
gel
astic
trans
form
atio
nof
time
serie
s.
Reco
rdin
g ne
ural
acti
vity
an
d ki
nem
atic
Dyna
mic
Tim
e w
arpi
ng
Kine
mati
csFe
atur
e ex
trac
tion
Kine
mati
c es
timati
on
Neu
ron
firin
g pa
ttern
Spec
tral
fe
atur
e ex
trac
tion
Kine
mati
c es
timati
on
Low
-pas
s filte
rKi
nem
atic
estim
ation
Aver
aged
spe
ctro
gram
(lef
t) a
nd a
vera
ged
spec
trogr
am a
fter w
arpi
ng (r
ight
).
Ada
pted
from
Sch
war
tz e
t al.,
200
6
are
pron
eto
trail-
by-tr
ail
varia
bilit
yin
term
sof
initi
atio
ntim
e,du
ratio
n,an
dsp
eed.
We
pres
ent
four
met
hods
toad
just
the
mov
emen
tva
riabi
lity
and
alig
nth
ene
ural
even
tsin
time
orin
time
and
frequ
ency
.Onc
e,th
ene
ural
even
tsar
etim
eal
igne
d,w
eca
nid
entif
yth
ene
ural
proc
esse
sat
tribu
ted
toth
em
ovem
ent
and
unco
vert
here
latio
nshi
pbe
twee
nth
eman
dup
perl
imb
kine
mat
ics.
Tim
e(s)
Frequency(Hz)
0.5
11.
52
2.5
33.
50102030405060708090100
Tim
e(s)
Frequency(Hz)
0.5
11.
52
2.5
33.
50102030405060708090100
Mov
emen
t pha
se
Estim
atio
n of
mov
emen
t kin
emat
ic p
aram
eter
sFr
oma
reha
bilit
atio
npe
rspe
ctiv
e,th
eul
timat
ego
alis
tobe
able
toof
fer
ate
chno
logi
cal
solu
tion
whe
reby
disa
bled
indi
vidu
als
with
out
the
abilit
yto
mov
evo
lunt
arily
can
cont
rol
exte
rnal
devi
ces
usin
gbr
ain
activ
ity.
Inou
rsi
mpl
epr
edic
tion
mod
el,
we
hypo
thes
ize
that
Upp
erlim
bpo
sitio
nan
dve
loci
tyar
een
code
din
toth
ebr
ain
activ
ityan
dth
efu
nctio
nal
rela
tions
hip
betw
een
EC
oGre
cord
ings
from
M1
and
uppe
rlim
bve
loci
tyis
linea
r.Th
us,
the
dyna
mic
albe
havi
our
ofth
ear
mca
nbe
pred
icte
dso
lely
from
EC
oGre
cord
ings
from
prim
ary
mot
orco
rtex
(M1)
.
reco
rdin
gsi
tes
dram
atic
ally
sim
plifi
esth
eB
CIs
yste
mde
sign
and
mak
esth
esy
stem
mor
efe
asib
lefro
men
gine
erin
gan
dcl
inic
alpe
rspe
ctiv
es.
Itis
antic
ipat
edth
atth
esy
stem
will
bein
tegr
ated
with
non-
inva
sive
reco
rdin
gm
etho
dslik
eE
EG
.Ifs
uch
para
digm
can
bede
ploy
edan
dst
anda
rdiz
ed,i
tope
nsa
path
toa
new
gene
ratio
nof
reha
bilit
atio
nan
dm
ovem
entr
esto
ratio
nde
vice
s.
Miy
atan
i M1 ,
Toto
sy d
e Ze
petn
ek J
O2 ,
Mas
ani M
1 , D
elpa
rte J
J1, P
opov
ic M
R1,
3 , C
rave
n B
C1,
4
1 Lyn
dhur
st c
ente
r, To
ront
o R
ehab
ilita
tion
Inst
itute
; 2D
epar
tmen
t of K
ines
iolo
gy, M
cMas
ter U
nive
rsity
; 3In
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eerin
g,
Uni
vers
ity o
f Tor
onto
; 4D
epar
tmen
t of M
edic
ine,
Uni
vers
ity o
f Tor
onto
Acu
te E
ffect
s of
Pas
sive
Sta
ndin
g an
d W
hole
Bod
y Vi
brat
ion
on A
rter
ial S
tiffn
ess
AB
STR
AC
T Th
e pu
rpos
e of
this
stu
dy w
as to
inve
stig
ate
the
acut
e ef
fect
s of
Who
le b
ody
vibr
atio
n (W
BV
) with
pa
ssiv
e st
andi
ng (
PS
) on
arte
rial
stiff
ness
in
able
-bod
ied
indi
vidu
als.
Thi
rteen
abl
e-bo
died
in
divi
dual
s (2
wom
en, a
ge: 2
4.6±
7.2
yrs)
per
form
ed W
BV
with
PS
(WB
V-tri
al) a
nd P
S a
lone
(PS
-tri
al)
on s
epar
ate
days
. The
WB
V-tri
al c
onsi
sted
of 5
-set
of 4
-min
vib
ratio
n w
ith in
ter-
set r
estin
g pe
riods
of 1
min
eac
h. In
the
PS
-tria
l, su
bjec
ts p
assi
vely
sto
od fo
r 25m
in. A
rteria
l stif
fnes
s (A
ortic
P
ulse
Wav
e Ve
loci
ty, a
PW
V)
was
mea
sure
d at
the
base
line,
20m
in a
nd 6
0min
afte
r bo
th tr
ials
. aP
WV
sig
nific
antly
dec
reas
ed a
t 20
-min
and
rec
over
ed t
o th
e ba
selin
e at
60-
min
in
both
the
W
BV-
trial
, and
PS
-tria
l (P
=0.0
1, 2
way
repe
ated
mea
sure
AN
CO
VA w
ith c
ovar
iate
s of
hea
rt ra
te).
Ther
e w
as n
o tri
al b
y tim
e in
tera
ctio
n. T
he r
esul
ts s
ugge
st t
hat
PS
itse
lf m
ay b
e fe
asib
le a
s a
ther
apy
to i
mpr
ove
arte
rial
stiff
ness
. M
ore
rese
arch
with
oth
er W
BV
pro
toco
ls a
re n
eede
d to
ex
amin
e th
e ef
fect
of W
BV
on
arte
rial s
tiffn
ess.
Con
tact
: miy
atan
i.mas
ae@
toro
ntor
ehab
.on.
ca
INTR
OD
UC
TIO
N
• In
crea
sed
arte
rial s
tiffn
ess
is a
n es
tabl
ishe
d co
rona
ry a
rtery
dis
ease
(C
AD
) ris
k am
ong
able
-bod
ied
peop
le. E
xerc
ise
redu
ces
arte
rial s
tiffn
ess
and
CA
D re
late
d m
orta
lity
• W
BV
exe
rcis
e de
crea
ses
arte
rial s
tiffn
ess
(Ots
uki e
t al.
2008
) in
able
-bod
ied
peop
le.
• A
mon
g in
divi
dual
s w
ith s
pina
l co
rd i
njur
y (S
CI)
pass
ive
stan
ding
(P
S)
with
an
aid
of
stan
ding
fra
me
has
tradi
tiona
lly b
een
reco
mm
ende
d as
par
t of
the
rape
utic
exe
rcis
e pr
ogra
ms
to m
aint
ain
the
heal
th.
• W
BV
with
PS
usi
ng a
sta
ndin
g fra
me
may
be
bene
ficia
l as
an
alte
rnat
e ex
erci
se t
o de
crea
se a
rteria
l stif
fnes
s in
dis
able
d pe
ople
suc
h as
peo
ple
with
SC
I.
• Th
e pu
rpos
e of
this
stu
dy w
as to
inve
stig
ate
the
effe
cts
of W
BV
with
PS
on
arte
rial s
tiffn
ess
in h
ealth
y yo
ung
men
and
wom
en o
n ao
rtic
PW
V.
RES
ULT
S (a
PWV)
•
A tw
o-w
ay r
epea
ted
mea
sure
s A
NO
VA d
id n
ot r
evea
l an
y si
gnifi
cant
mai
n ef
fect
s or
in
tera
ctio
n fo
r aP
WV
(Fig
ure
4). A
mai
n ef
fect
for t
ime
appr
oach
ed s
igni
fican
ce ( p
=0.0
65).
• W
hen
cont
rolli
ng f
or H
R, A
NV
OC
A re
veal
ed t
hat
ther
e w
as a
sig
nific
ant
mai
n ef
fect
for
tim
e (p
=0.0
06).
Pos
t ho
c an
alys
es r
evea
led
that
the
sou
rce
of t
he e
ffect
was
due
to
subj
ects
hav
ing
a si
gnifi
cant
dec
reas
e in
PW
V 2
0 m
inut
es fo
llow
ing
stan
ding
whe
ther
or
not t
hey
rece
ived
vib
ratio
n (F
igur
e 5)
. aP
WV
no
long
er d
iffer
ed fr
om b
asel
ine
60m
inut
es
post
sta
ndin
g.
CO
NC
LUSI
ON
•
WB
V +
PS
and
PS
alo
ne i
mpr
oved
arte
rial
stiff
ness
. Th
e st
udy
resu
lts s
ugge
st t
hat
pass
ive
stan
ding
may
be
used
as
a th
erap
y to
redu
ce a
rteria
l stif
fnes
s.
MET
HO
DS
Subj
ects
•
Ele
ven
mal
es a
nd tw
o fe
mal
es (A
ge: 2
4.6
± 7.
2 yr
s; H
eigh
t: 17
1.6
± 7.
9 cm
; Wei
ght:
64.5
±
12.2
kg)
Prot
ocol
(Fig
ure
1)
• S
ubje
cts
parti
cipa
ted
in tw
o se
ssio
ns (
one
WB
V a
nd 1
PS
) fo
r 25
min
utes
follo
win
g a
30
min
ute
rest
per
iod
• O
utco
me
mea
sure
s w
ere
mea
sure
d at
bas
elin
e, 2
0 m
inut
es p
ost-v
ibra
tion,
and
60
min
utes
pos
t vib
ratio
n
Out
com
e M
easu
res
• H
eart
rate
(H
R),
syst
olic
blo
od p
ress
ure
(SB
P),
dias
tolic
blo
od p
ress
ure
(DB
P)
wer
e m
easu
red.
Mea
n bl
ood
pres
sure
(MB
P) w
as c
alcu
late
d as
[DB
P+
1/3(
SB
P-D
BP
)].
• A
ortic
pul
se w
ave
velo
city
(aP
WV
) was
mea
sure
d as
an
inde
x of
arte
rial s
tiffn
ess
(Tan
aka
et a
l. 19
98)
WB
V •
Mod
ified
W
AVE
P
ro
plat
form
(W
hole
-bod
y A
dvan
ced
Vibr
atio
n E
xerc
ise,
W
inds
or,
Can
ada)
with
Eas
ySta
nd 5
000
(Fig
ure
2). S
ubje
cts
wer
e ex
pose
d to
5 s
ets
of 4
min
25H
z,
1.2m
m p
eak-
to-p
eak
disp
lace
men
t vib
ratio
n w
ith k
nees
ext
ende
d.
Sup
ine
Res
t (3
0min
) W
BV
or P
S
(25m
in: 4
min
ON
1m
in O
FF x
5se
ts)
Sup
ine
Res
t (6
0min
)
MET
HO
DS
Mea
sure
men
t of a
PWV
• Ti
me
(∆t)
was
mea
sure
d us
ing
two
iden
tical
non
-inva
sive
tran
scut
aneo
us D
oppl
er
flow
met
ers
(Sm
artd
op50
, Had
eco,
Inc.
, Jap
an)
(Fig
ure
3a).
The
aver
age
of a
t lea
st
20 w
avef
orm
s w
ere
used
to c
alcu
late
∆t.
• D
ista
nce
(D)
was
mea
sure
d ov
er t
he s
urfa
ce o
f th
e bo
dy u
sing
a m
etal
tap
e m
easu
re (F
igur
e 3b
) •
aPW
V (c
m/s
ec) =
D / ∆t
Ana
lysi
s •
Two-
way
repe
ated
mea
sure
s an
alys
es o
f var
ianc
e (A
NO
VA) w
ith tw
o w
ithin
-sub
ject
va
riabl
es (C
ondi
tion:
PS
, WB
V;
time:
0, 2
0, 6
0) w
ere
cond
ucte
d to
ana
lyze
aP
WV
•
Ana
lyse
s of
cov
aria
nce
(AN
CO
VA)
adju
stin
g fo
r ef
fect
s of
HR
and
MB
P w
ere
also
co
nduc
ted
Figu
re 1
. Out
com
e m
easu
res
wer
e ta
ken
at b
asel
ine,
20m
in p
ost-v
ibra
tion,
and
60m
in p
ost-v
ibra
tion.
Figu
re 2
. S
ubje
cts
wer
e ex
pose
d to
WB
V
with
a m
odifi
ed W
AVE
Pro
pla
tform
fitt
ed
with
an
Eas
ySta
nd 5
000.
Figu
re 3
. (a)
mea
sure
men
t of w
ave
form
late
ncy
(∆t);
(b)
mea
sure
men
t of
dis
tanc
e (D
) be
twee
n ca
rotid
arte
ry (C
A) a
nd fe
mor
al a
rtery
(FA
)
The
auth
ors
ackn
owle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der
the
Pro
vinc
ial R
ehab
ilita
tion
Res
earc
h P
rogr
am fr
om th
e M
inis
try o
f Hea
lth a
nd L
ong-
Term
Car
e in
Ont
ario
. The
vie
ws
expr
esse
d do
not
nec
essa
rily
refle
ct th
ose
of th
e M
inis
try.”
Tabl
e 1.
Blo
od p
ress
ure
and
hear
t rat
e be
fore
and
afte
r tria
ls (M
ean±
SD).
* p<0
.05
vs b
asel
ine.
-60
-40
-20020406080
Bas
elin
eP
ost 2
0min
Pos
t 60m
in
aPWV (residuals of HR)
Figu
re 5
. W
hen
cont
rolli
ng H
R,
aPW
V w
as s
how
n to
sig
nific
antly
dec
reas
e 20
min
pos
t st
andi
ng
rega
rdle
ss o
f PS
or W
BV
con
ditio
n. T
he e
ffect
s w
as n
o lo
nger
pre
sent
60m
in p
ost s
tand
ing.
RES
ULT
S (B
P an
d H
R)
REF
EREN
CES
•
Ots
uki e
t al.
Act
a P
hysi
ol 1
94(3
):189
-94,
200
8
• Ta
naka
et a
l. A
rterio
scle
r Thr
omb
Vasc
Bio
l. 18
(1):1
27-3
2, 1
998
DIS
CU
SSIO
N
• W
BV
+ P
S a
nd P
S a
lone
red
uced
arte
rial
stiff
ness
, al
thou
gh t
he m
echa
nism
s re
mai
ns
uncl
ear.
We
spec
ulat
e th
at t
he a
cute
red
uctio
ns o
f ar
teria
l st
iffne
ss a
fter
PS
may
be
asso
ciat
ed w
ith t
he a
rteria
l fun
ctio
nal c
hang
es (
i.e.
endo
thel
ial f
unct
ion)
due
to
incr
ease
d bl
ood
volu
me
in lo
wer
bod
y.
• M
ore
rese
arch
with
oth
er W
BV
pro
toco
l (i.
e. D
urat
ion,
fre
quen
cy a
nd a
mpl
itude
) is
de
finite
ly n
eede
d to
exa
min
e th
e ef
fect
of W
BV
on
arte
rial s
tiffn
ess.
D (c
m) C
A FA
6 6.
5 7
7.5
8
FA
∆t (s
ec)
Tim
e (s
ec)
CA
(a)
(b)
Bas
elin
ePo
st 2
0 m
inPo
st 6
0 m
inPS
119
± 8
115
± 8
116
± 11
WB
V11
9 ±
1311
7 ±
1011
4 ±
7
PS88
± 9
85 ±
888
± 1
0W
BV
87 ±
12
88 ±
10
83 ±
12
PS73
± 1
171
± 9
75 ±
12
WB
V72
± 1
274
± 1
168
± 1
5
PS63
± 1
060
± 1
058
± 7
*W
BV
61 ±
858
± 8
58 ±
7
SBP
(mm
Hg)
MB
P (m
mH
g)
DB
P (m
mH
g)
HR
(bea
ts/m
in)
500
600
700
800
900
1000
1100
Bas
elin
eP
ost 2
0min
Pos
t 60m
in
aPWV (cm/sec)
500
600
700
800
900
1000
1100
Bas
elin
eP
ost 2
0min
Pos
t 60m
in
aPWV (cm/sec)
Indi
vidu
als
valu
esM
ean
PS
WBV
Figu
re 4
. Raw
aP
WV
sco
res
for s
ubje
cts
durin
g th
e P
S (l
eft)
and
WB
V c
ondi
tions
(rig
ht).
Bas
elin
e 2
0min
pos
t 6
0min
pos
t
*
Backg
rou
nd
To
in
ves
tig
ate
the
rela
tio
nsh
ip
bet
wee
n
seru
m
25
(OH
)D
lev
els
and
b
on
e
healt
h
ou
tco
mes
(vB
MD
, co
rtic
al
thic
kn
ess
, an
d
trab
ecu
lar
stru
ctu
re
par
amet
ers)
fro
m p
QC
T s
can
s o
f th
e ti
bia
in
in
div
idu
als
wit
h c
hro
nic
SC
I.
Pu
rpo
se
Meth
od
s
Stu
dy
Des
ign
& S
etti
ng
: C
ross
-sec
tio
nal
; T
oro
nto
Reh
ab,
Ly
nd
hu
rst
Cen
tre
and
Mc M
aste
r U
niv
ersi
ty
Pa
rtic
ipa
nts
: 4
0 a
du
lts
wit
h c
hro
nic
SC
I (
C2
-T1
2 A
IS A
-D)
Ass
essm
ent
Tec
hn
iqu
es &
Ou
tco
mes
:
1.
Ser
um
25
(OH
)D (
nm
ol/
L);
Dia
So
rin
LIA
ISO
N®
CL
IA
Vit
amin
D s
tatu
s w
as c
lass
ifie
d a
s:
•
Su
ffic
ien
t (≥
75
nm
ol/
L)
•
Insu
ffic
ien
t 2
(5
0-7
4 n
mo
l/L
)
•
Def
icie
nt
(<5
0 n
mo
l/L
)
2.
Bo
ne
qu
alit
y o
utc
om
es;
Str
aTec
XC
T 2
00
0 p
QC
T
•
4%
ti
bia
tr
abec
ula
r v
BM
D
(mg
/cm
3),
co
nn
ecti
vit
y
(no
des
),
mea
n h
ole
siz
e (m
m2),
max
imu
m h
ole
siz
e (m
m2)
•
66
% t
ibia
vB
MD
(m
g/c
m3),
co
rtic
al t
hic
kn
ess
(mm
) A
na
lysi
s:
Sp
earm
an
corr
elat
ion
s w
ere
use
d
to
asse
ss
the
asso
ciat
ion
s
bet
wee
n 2
5(O
H)D
an
d b
on
e q
ual
ity
ou
tco
mes
. C
orr
elat
ion
s w
ere
des
crib
ed
as:
no
(r
=0
.0-0
.19
),
wea
k
(r=
0.2
-0.3
9),
m
od
erat
e
(r=
0.4
-0.6
9),
st
ron
g
(r=
0.7
-1.0
) as
soci
atio
ns
and
p
<0
.05
was
co
nsi
der
ed s
ign
ific
ant.
Ta
ble
1. P
arti
cip
ant
Ch
arac
teri
stic
s
SC
I-1
SC
I-4
SC
I-3
SC
I-2
1.
Ese
r P,
Sch
iess
l H
, W
illn
ecker
J.
Bone
loss
and s
tead
y s
tate
aft
er s
pin
al c
ord
inju
ry:
a cr
oss
sect
ional
stu
dy u
sing p
QC
T. J
Musc
ulo
skel
et N
euro
nal
Inte
ract
. 2004 J
un;
4(2
): 1
97-8
.
2.
Ese
r P,
Fro
tzle
r A
, Z
ehnder
Y,
Den
oth
J.
Fra
cture
thre
shold
in t
he
fem
ur
and t
ibia
of
peo
ple
wit
h s
pin
al c
ord
inju
ry a
s det
erm
ined
by p
erip
her
al q
uan
tita
tive
com
pute
d t
om
ogra
phy.
Arc
h P
hys
Med
Reh
abil
. 2005 M
ar;
86(3
): 4
98-5
04.
3.
Laz
o M
G,
Shir
azi
P, S
am M
, G
iobb
ie-H
urd
er A
, B
lacc
onie
re M
J, M
upp
idi
M.
Ost
eop
oro
sis
and r
isk o
f fr
actu
re i
n m
en w
ith s
pin
al c
ord
inju
ry. Spin
al
Cord
. 2001 A
pr;
39(4
): 2
08-1
4.
4.
Bau
man
WA
, Z
hong Y
-G,
Sch
war
tz E
. V
itam
in D
def
icie
ncy
in
vet
eran
s w
ith ch
ronic
spin
al c
ord
inju
ry. M
etaboli
sm. 1995;
44(1
2):
1612-1
616.
5.
Lau
reta
ni
F,
Ban
din
elli
S,
Russ
o C
R,
Mag
gio
M,
Di
lori
o A
, C
her
ub
ini A
, M
aggio
D,
Ced
a
GP,
Val
enti
G,
Gura
lnik
JM
, F
erru
cci
L.
Corr
elat
es o
f b
one
qual
ity i
n o
lder
per
sons.
Bone.
2006;
39(4
): 9
15-9
12.
SC
I-B
CO
N-1
C
ON
-2
Ex
ten
siv
e su
ble
sio
nal
bo
ne
loss
occ
urs
fo
llo
win
g S
CI1
, re
sult
ing
in
a
hig
h
frag
ilit
y
frac
ture
su
scep
tib
ilit
y2.
Cu
rren
t g
uid
elin
es
for
det
erm
inin
g
frac
ture
ris
k a
re u
nsu
itab
le f
or
the
SC
I p
op
ula
tio
n3.
Iden
tifi
cati
on
of
risk
fact
ors
ass
oci
ated
wit
h b
on
e lo
ss m
ay h
elp
dis
tin
gu
ish
bet
wee
n i
nd
ivid
ual
s
wit
h S
CI
wh
o f
ract
ure
an
d t
ho
se w
ho
do
no
t fr
actu
re.
Vit
amin
D i
nta
ke
is a
mo
dif
iab
le f
acto
r th
at c
ou
ld c
han
ge
frac
ture
ris
k
afte
r S
CI4
. P
erip
her
al q
uan
tita
tiv
e co
mp
ute
d t
om
og
rap
hy
(p
QC
T)
allo
ws
for
char
acte
riza
tio
n o
f ch
ang
es i
n v
BM
D a
nd
bo
ne
stru
ctu
re;
ho
wev
er n
o p
rio
r
wo
rk h
as e
xp
lore
d t
he
rela
tio
nsh
ips
bet
wee
n s
eru
m v
itam
in D
sta
tus
and
low
er e
xtr
emit
y t
ibia
vB
MD
or
stru
ctu
re v
aria
ble
s in
th
e S
CI
pop
ula
tio
n.
•
Th
ere
wer
e n
o s
ign
ific
ant
asso
ciat
ion
s b
etw
een
ser
um
25
(OH
)D l
evel
wit
h
trab
ecu
lar
vB
MD
an
d
trab
ecu
lar
stru
ctu
re
ou
tco
mes
in
in
div
idu
als
wit
h
chro
nic
SC
I, c
on
trar
y t
o f
ind
ing
s in
th
e n
on
-SC
I p
op
ula
tio
n5.
•
Th
ere
was
a w
eak
neg
ativ
e co
rrel
atio
n (
r=-0
.22
7,
p=
0.1
89
) b
etw
een
ser
um
25
(OH
)D a
nd
6
6%
tib
ia c
ort
ical
th
ick
nes
s,
wh
ich
was
no
t si
gn
ific
ant.
•
Lim
itat
ion
s o
f th
is s
tud
y i
ncl
ud
e: s
mal
l sa
mp
le s
ize,
rel
ativ
e im
pai
rmen
t
ho
mo
gen
eity
, d
ura
tio
n o
f in
jury
bia
s an
d s
ing
le t
ime
po
int
of
dat
a co
llec
tio
n.
• P
rosp
ecti
ve
stu
dy
of
the
asso
ciat
ion
s b
etw
een
bo
ne
qu
alit
y a
nd
25
(OH
)D
stat
us
ov
er t
ime
in a
lar
ger
co
ho
rt o
f in
div
idu
als
may
fac
ilit
ate
iden
tify
ing
tho
se f
or
wh
om
:
•
Th
erap
euti
c ra
ng
e v
itam
in D
en
han
ces
bo
ne
arch
itec
ture
th
ereb
y
pro
vid
ing
fra
ctu
re p
rote
ctio
n
•
In
suff
icie
nt
lev
els
enab
le f
ract
ure
ris
k p
red
icti
on
.
Ser
um
25(O
H)D
Lev
els
an
d T
ibia
Volu
met
ric
Bon
e M
iner
al
Den
sity
(vB
MD
) in
Ch
ron
ic S
pin
al
Cord
In
jury
(S
CI)
K H
um
mel
1,2, B
C C
raven
2,3, L
Th
ab
an
e4, JD
Ad
ach
i4, A
Pap
aio
an
nou
4, N
McC
art
ney
4, M
R P
op
ovic
2,3, L
M G
ian
gre
gori
o1
,2,4
1U
niv
ersi
ty o
f W
ater
loo,
2T
oro
nto
Reh
abil
itat
ion I
nst
itute
, 3U
niv
ersi
ty o
f T
oro
nto
, 4M
cMas
ter
Univ
ersi
ty
Resu
lts
Dis
cu
ssio
n
Refe
ren
ces
Ackn
ow
led
gem
en
ts
Ma
le!
Fem
ale
!T
ota
l!
To
tal
n!
32
!8
!4
0!
Ag
e (y
ears
) !
52
(±
11
.8)!
50
(±
14
.1)!
51
(±
12
.0)!
Mo
tor
Co
mp
lete
Pa
rap
leg
ia (
n)!
16
!4
!2
0!
Mo
tor
Inco
mp
lete
Pa
rap
leg
ia (
n)!
3!
2!
5!
Mo
tor
Co
mp
lete
Tet
rap
leg
ia (
n)!
6!
0!
6!
Mo
tor
Inco
mp
lete
Tet
rap
leg
ia (
n)!
7!
2!
9!
Tim
e p
ost
in
jury
(y
ears
) !
15
(±
10
.8)!
15
(±
9.3
)!1
5 (
±1
0.0
)!
Sp
earm
an
Co
rrel
ati
on
wit
h S
eru
m 2
5(O
H)D
!
Mea
n (
± S
D)
N!
r!p
va
lue!
4%
Tib
ia S
ite
Tra
bec
ula
r v
BM
D (
mg
/cm
3)!
14
2.6
(±
51
.4)
36
!-0
.10
9!
0.5
35
!
Co
nn
ecti
vit
y I
nd
ex (
no
des
/un
it o
f co
nn
ecte
d n
etw
ork
)!0
.18
9 (
±0
.07
5)
15
!0
.03
6!
0.9
00
!
Mea
n H
ole
Siz
e B
etw
een
Tra
bec
ula
e (m
m2)!
7.8
5 (
±1
0.6
2)
15
!0
.03
2!
0.9
10
!
Max
imu
m H
ole
Siz
e B
etw
een
Tra
bec
ula
e (m
m2)!
62
8.2
7 (
±3
27
.41
) 1
5!
0.0
14
!0
.96
0!
66
% T
ibia
Sit
e
Sh
aft
vB
MD
(m
g/c
m3)!
10
80
.3 (
±5
6.8
) 3
4!
-0.1
76
!0
.311
!
Sh
aft
Co
rtic
al T
hic
kn
ess
(mm
)!3
.18
(±
1.0
8)
34
!-0
.22
7!
0.1
89
!
Ta
ble
2.
(lef
t) S
um
mar
y o
f
trab
ecu
lar
an
d
co
rtic
al
bo
ne
hea
lth
o
utc
om
es an
d
Sp
earm
an c
orr
elat
ion
s w
ith
seru
m 2
5(O
H)D
lev
el
Fig
ure
2
. (a
bo
ve)
L
inea
r
rela
tio
nsh
ip
bet
wee
n
66
%
tib
ia c
ort
ical
th
ick
nes
s an
d
se
rum
2
5(O
H)D
le
ve
l
(r=
-0.2
27
, p
=0
.18
9)
0.0
10
.0
20
.0
30
.0
40
.0
50
.0
60
.0
70
.0
80
.0
90
.0
10
0.0
Vit
am
in D
Sta
tus
Su
ffic
ien
t (≥
75
nm
ol/
L)
Insu
ffic
ien
t (5
0-7
4 n
mo
l/L
)D
efi
cie
nt
(<5
0 n
mo
l/L
)% Population ±95% Confidence
Fig
ure
1.
(ab
ov
e) P
erce
nt
of
coh
ort
(N
=4
0)
± 9
5%
CI
gro
up
ed b
y v
itam
in
D s
tatu
s.
62
.5 ±
15
%
25
.0 ±
13
%
12
.5 ±
10
%
0.0
1.0
2.0
3.0
4.0
5.0
6.0
050
100
150
200
250
66% Tibia Cotical Thickness (mm)
Ser
um
25
(OH
)D (
nm
ol/
L)r
= -
0.2
27
p =
0.1
89
This
re
sear
ch
was
fu
nded
b
y
the
Onta
rio
Neu
rotr
aum
a F
oundat
ion
(Gra
nt
#:
2009-S
CI-
PH
D-6
84),
the
Can
adia
n I
nst
itute
s fo
r H
ealt
h R
esea
rch (
Gra
nt
#:
177254),
and t
he
Sp
inal
Cord
Inju
ry S
olu
tions
Net
work
.
• W
hole
-bod
y vi
brat
ion
(WBV)
is a
new
the
rapy
use
d fo
r im
prov
ing
mus
cle
stre
ngth
, en
dura
nce,
po
wer
an
d bon
e m
iner
al
den
sity
(B
MD
) in
an
imal
s,
pos
t m
enop
ausa
l w
omen
, ba
riat
ric
pers
ons,
elit
e at
hlet
es
and
child
ren
with
neu
rolo
gica
l im
pairm
ents
.
• Alth
ough
pop
ular
in
man
y re
habi
litat
ion
sett
ings
, th
e us
abili
ty
of
WBV
amon
g pa
tient
s w
ith
spin
al
cord
in
jury
(SCI)
is u
nkno
wn.
• Age
: 20
–50y
rs;W
eigh
t:68
–115
kg;
Hei
ght;
168–
188c
m
• SCI:
n=
8 (C
4-L2
AIS
A-D
); N
on-S
CI:
n=
10
B. Catharin
e Craven
MD, 2,
3 Step
hanie C. Hadi,1 Ju
de J. Delparte MSc,2 Milad Aliza
deh-‐Meghrazi MAS
c,2,3 Lora M. G
iangregorio
PhD
1 , Alan R. M
orris PhD
, 4 Sande
r L. H
itzig PhD
,2 M
ilos R
. Pop
ovic PhD
,2 ,3
1 University
of W
aterloo, 2 To
ronto Re
habilitaL
on InsLtute, 3 University
of T
oron
to 4 Arcon Engine
ering
• Th
ere
wer
e no
ove
rall
differ
ence
in
the
num
ber
of
posi
tive
(115
) or
neg
ativ
e (1
04)
com
men
ts r
epor
ted
• SC
I su
bjec
ts
repo
rted
si
gnifi
cant
ly
mor
e po
sitive
st
atem
ents
(81
) th
an n
egat
ive
stat
emen
ts (
34
• N
on-S
CI
subj
ects
rep
orte
d si
gnifi
cant
ly m
ore
nega
tive
stat
emen
ts (
74)
than
pos
itive
sta
tem
ents
(30
)
• Th
e pa
ram
eter
co
mbi
natio
ns
gene
ratin
g th
e m
ost
nega
tive
com
men
ts
wer
e W
AVE
high
, 14
0°,
25H
z,
and
WAV
E hi
gh,
160°
, 25
Hz
and
35H
z
• Th
e pa
ram
eter
co
mbi
natio
ns
gene
ratin
g th
e m
ost
posi
tive
repo
rts
wer
e: W
AVE
low
, 14
0°,
35H
z/45
Hz,
an
d W
AVE
low
, 16
0°,
25H
z
The
view
s ex
pres
sed
in
this
po
ster
do
no
t ne
cess
arily
ref
lect
tho
se o
f an
y of
the
gra
ntin
g ag
enci
es.
SU
BJE
CTS
BA
CK
GR
OU
ND
Usability of th
e Juvent™ and
WAV
E® W
hole Bod
y Vibra;
on
Plates fo
r Men
with
and
with
out S
pina
l Cord Injury
Gra
nt
#:
ON
F-S
CI-
20
06
-WA
VE
-44
5
CO
DIN
G F
RA
MEW
OR
K
• S
ub
ject
s w
ere
e
xp
ose
d
to apriori
se
lect
ed
com
bina
tions
of
vibr
atio
n pa
ram
eter
s on
the
mod
ified
W
AVE®
and
Juv
ent™
WBV de
vice
s (S
ee F
igur
e 1)
.
• Vib
ratio
n Pa
ram
eter
Com
bina
tions
Kne
e an
gle:
140
o , 1
60o
Freq
uenc
y: 2
5, 3
5 &
45
Hz
Dev
ice/
Am
plitu
de:
WAV
E H
igh
(1.1
mm
)
WAV
E Lo
w (
0.7m
m)
J
uven
t (
0.05
mm
)
wer
e pr
esen
ted
syst
emat
ical
ly for
tw
o m
inut
es w
ith
a on
e m
inut
e re
st p
erio
d
WH
OLE
BO
DY
VIB
RA
TIO
N
Typ
e
Vib
rati
on D
escr
ipto
rs
Posi
tive
Euph
oria
M
assa
ge
Plea
sant
ness
Re
duce
d sp
astic
ity
Easy
to
see
Th
erap
eutic
In
crea
sed
sens
itivi
ty W
arm
th
Opt
imal
En
joym
ent
Fun
Rela
Sm
ooth
Neg
ativ
e
Blu
rred
vis
ion
N
umbn
ess
Dis
com
fort
Sha
king
hea
d In
duce
d sp
asm
s U
ritic
aria
N
ause
a Ve
rtig
o W
orse
ning
pai
n
Ann
oyan
ce
Bot
hers
ome
Irrita
ting
Pres
sure
fro
m a
ngle
D
isco
mfo
rt
• S
ubje
ct’s
ex
peri
ence
s du
ring
an
d af
ter
vibr
atio
n ex
posu
re
wer
e so
licit
ed
thro
ugh
sem
i-st
ruct
ured
in
terv
iew
s
• Re
port
s w
ere
code
d as
neu
tral
, po
sitiv
e, o
r ne
gativ
e (C
odin
g Fr
amew
ork;
neu
tral
not
sho
wn)
• To
ass
ess
SCI
and
non-
SCI
subj
ects
’ fe
edba
ck o
n th
e us
abili
ty
of
the
Juve
nt™
an
d W
AVE®
W
BV
devi
ces
usin
g sp
ecifi
ed
knee
an
gles
, pl
ate
ampl
itude
s an
d fr
eque
ncie
s.
PU
RP
OS
E
OU
TCO
ME
AS
SES
SM
ENT
CO
ND
ITIO
N-S
PEC
IFIC
RES
ULT
S
♦ = sig
nificant d
ifferen
ces b
etween vibraL
on param
eters
● = sig
nificant d
ifferen
ces b
etween SCI and
non
-‐SCI
• W
here
as
non-
SCI
subj
ects
fo
und
high
er
freq
uenc
y vi
brat
ions
unp
leas
ant,
SCI
subj
ects
pre
ferr
ed t
hese
vi
brat
ion
para
met
er
com
binat
ions.
S
CI
rela
ted
impa
irm
ents
al
ter
WB
V
perc
epti
on;
pote
nti
ally
m
aski
ng a
dver
se e
ffec
ts.
• A i
nter
vent
ion
stud
y us
ing
WBV p
aram
eter
s of
WAV
E lo
w,
140o
, 45
Hz
is u
nder
way
bas
ed o
n th
is u
sabi
lity
data
sug
gest
ing
likel
y ad
here
nce
in S
CI
subj
ects
.
CO
NC
LUS
ION
OV
ERA
LL R
ESU
LTS
Cont
act: c
rave
n.ca
thy@
toro
ntor
ehab
.on.
ca
Figure 1. Mod
ified
WAV
E® (leJ) an
d Juvent
™
(right) W
BV devices
Ob
ject
ives
§
To a
sses
s th
e ef
fect
s of
spe
cific
vib
ratio
n pa
ram
eter
s on
low
er
extr
emity
EM
G a
ctiv
atio
n in
ind
ivid
uals
with
SCI
during
exp
osur
e to
pas
sive
sta
ndin
g an
d W
BV.
§
To d
escr
ibe
the
effe
cts
of k
nee
angl
e on
EM
G a
ctiv
atio
n an
d de
term
ine
the
optim
al a
ngle
to
elic
it EM
G a
ctiv
atio
n.
§ To
co
mpar
e th
e W
ave®
an
d Ju
vent™
W
BV
pla
tform
s’
effe
ctiv
enes
s in
el
icit
ing
low
er
extr
emit
y EM
G
acti
vity
in
in
divi
dual
s w
ith S
CI.
Dis
cuss
ion
Ef
fect
of
Freq
uenc
y on
EM
G:
§ Fr
eque
ncy
variat
ions
had
a s
igni
fican
t ef
fect
with
the
WAV
E®
plat
form
for
bot
h AB a
nd S
CI
subj
ects
for
all
mus
cles
(ex
cept
VL
in S
CI)
. §
45
Hz
vibr
atio
n ge
nera
ted
the
grea
test
ac
tiva
tion
of
EM
G
com
pare
d to
the
res
ting
cond
ition
. Ef
fect
of
Am
plitu
de o
n EM
G:
§ Am
plitu
de v
aria
tions
had
a s
igni
fican
t ef
fect
with
the
WAV
E®
plat
form
fo
r al
l m
uscl
es
in
AB
subj
ects
an
d fo
r G
M
and
RF
mus
cles
in S
CI
subj
ects
. §
1.2
mm
vib
ratio
n el
icite
d gr
eate
r EM
G a
ctiv
atio
n th
an 0
.6 m
m
with
the
WAV
E® p
latf
orm
. Ef
fect
of
Post
ure
on E
MG
: §
Post
ure
variat
ions
di
d no
t ha
ve
a si
gnifi
cant
ef
fect
on
EM
G
activ
atio
n.
§ G
reat
er E
MG
act
ivat
ion
with
140
o &
160
o kn
ee a
ngle
s fo
r bo
th
plat
form
s.
Com
paring
Wav
e® a
nd J
uven
t™:
§ Th
e W
AVE®
pla
tfor
m a
ugm
ente
d EM
G a
ctiv
ity t
o a
muc
h gr
eate
r de
gree
th
an
the
Juve
nt™
pl
atfo
rm
(no
activ
atio
n w
ith
SCI
subj
ects
on
the
Juve
nt™
).
Su
pp
ort:
The
aut
hors
ack
now
ledg
e th
e su
ppor
t of
the
Ont
ario
Neu
rotr
aum
a Fo
unda
tion
(#20
07-S
CIS
O-5
84)
and
the
Toro
nto
Reha
bilit
atio
n In
stitu
te w
ho r
ecei
ves
fund
ing
unde
r th
e Pr
ovin
cial
Reh
abili
tatio
n Re
sear
ch
Prog
ram
fro
m t
he M
inis
try
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io.
The
view
s ex
pres
sed
do n
ot n
eces
sarily
re
flect
tho
se o
f th
e M
inis
try.
Equ
ipm
ent
and
spac
e ha
ve b
een
fund
ed w
ith g
rant
s fr
om t
he C
anad
a Fo
unda
tion
for
Inno
vatio
n, O
ntar
io I
nnov
atio
n Tr
ust
and
the
Min
istr
y of
Res
earc
h an
d In
nova
tion.
Wh
ole
Bod
y V
ibra
tion
an
d E
MG
Act
ivat
ion
: Ef
fect
s of
V
ibra
tion
Fre
qu
ency
, A
mp
litu
de
and
Pos
ture
M
Aliz
adeh
-Meg
hraz
i1,2,
K M
asan
i1,
D S
ayen
ko1 ,
MR P
opov
ic1,
2 , B
C C
rave
n1,3
1 T
oron
to R
ehab
; 2 I
BBM
E, U
nive
rsity
of
Toro
nto;
3D
epar
tmen
t of
Med
icin
e U
nive
rsity
of
Toro
nto
Toro
nto
Reh
ab is
a t
each
ing
and
rese
arch
hos
pita
l ful
ly a
ffili
ated
with
the
Uni
vers
ity o
f To
ront
o.
Bac
kgro
un
d
§ In
divi
dual
s w
ho su
stai
n a
spin
al co
rd in
jury
(S
CI)
ex
perien
ce
mus
cle
atro
phy
in
thei
r lo
wer
ex
trem
itie
s as
a
resu
lt
of
dene
rvat
ion
and
lack
of
mec
hani
cal
stim
ulus
bel
ow t
he l
evel
of
inju
ry.
Ther
e is
a 1
8-46
% r
educ
tion
in l
ower
ext
rem
ity m
uscl
e cr
oss
sect
iona
l are
a si
x w
eeks
aft
er S
CI
com
pare
d to
con
trol
.
§ Cur
rent
low
er e
xtre
mity
reh
abili
tatio
n m
etho
ds inc
lude
fun
ctio
nal
elec
tric
al s
imul
atio
n, b
ody-
wei
ght
supp
ort
trea
dmill
tra
inin
g, g
ait
trai
ning
, a
nd p
assi
ve s
tand
ing.
§
Who
le-B
ody
Vib
rati
on
(WB
V)
is
a no
vel
ther
apy
used
fo
r au
gmen
ting
mus
cle
activ
ity a
nd im
prov
ing
mus
cle
stre
ngth
in t
he
able
-bod
ied
popu
latio
n.
Met
hod
s Sub
ject
s §
Abl
e-bo
died
sub
ject
s (n
=7)
§
SCI
subj
ects
(n=
5)
Qua
ntita
tive
anal
ysis
: §
Cal
cula
te E
MG
act
ivity
dur
ing
WBV f
or d
iffer
ent
cond
ition
s.
§ Com
pare
mag
nitu
de o
f EM
G d
urin
g W
BV a
nd r
estin
g co
nditi
ons.
§
EMG
act
ivity
rec
orde
d us
ing
bipo
lar
silv
er-s
ilver
chl
orid
e su
rfac
e el
ectr
odes
on
the
follo
win
g m
uscl
es (
Gai
n =
200
0, p
re a
mpl
ified
, 60
Hz
reje
ctio
n ra
tio,
Fs =
200
0 H
z):
Con
trol
led
Para
met
ers
§ Vib
ratio
n Fr
eque
ncy:
25,
35,
45H
z §
Vib
ratio
n Am
plitu
de:
0.6
& 1
.2m
m
§ Kne
e Ang
les:
140
o , 1
60o ,
180
o
Con
clu
sion
s §
The
pass
ive
stan
ding
an
d W
BV pl
atfo
rm co
nfig
urat
ion
elic
ited
elic
iting
EM
G a
ctiv
ity in
the
low
er e
xtre
mity
mus
cles
in in
divi
dual
s w
ith S
CI
and
able
-bod
ied
subj
ects
.
§ Th
e su
gges
ted
optim
al p
aram
eter
s fo
r gr
eate
st E
MG
act
ivat
ion
in
the
low
er e
xtre
miti
es a
re 4
5 H
z, 0
.6m
m,
140o
or
160o
, du
ring
pa
ssiv
e st
andi
ng w
ith t
he W
ave®
pla
tfor
m.
§ D
ue t
o th
e hi
gher
am
plitu
de o
f vi
brat
ion
prov
ided
by
the
Wav
e®
plat
form
, it
crea
ted
grea
ter
EMG
ac
tivat
ion
com
pare
d to
th
e Ju
vent
™ p
latf
orm
, su
gges
ting
its g
reat
er p
oten
tial
for
elic
iting
EM
G a
ctiv
ity.
The
view
s ex
pres
sed
in
this
po
ster
do
no
t ne
cess
arily
ref
lect
tho
se o
f an
y of
the
gra
ntin
g ag
enci
es.
Con
tact
: M
ilad
Aliz
adeh
-Meg
hraz
i To
ront
o R
ehab
ilita
tion
Inst
itute
E
mai
l: m
ilad.
aliz
adeh
.m@
utor
onto
.ca
Pho
ne: (
416)
597
-342
2 ex
t. 62
13
Sig
nal
Filt
erin
g
§ Cus
tom
filt
ers
wer
e ap
plie
d to
the
raw
EM
G s
igna
l to
el
imin
ate
mot
ion
arti
fact
s an
d el
ectr
o-m
agnet
ic
inte
rfer
ence
s fr
om t
he v
ibra
tion
plat
form
s.
§ Th
e EM
G s
igna
l w
as n
otch
filt
ered
(po
wer
= 0
) at
the
vi
brat
ion
freq
uenc
y an
d its
har
mon
ics.
§
The
EMG
sig
nal w
as n
orm
aliz
ed b
y th
e #
of
FFT
poin
ts
afte
r no
tch
filte
ring
.
§ Ti
bial
is A
nter
ior
§ Sol
eus
§ G
astr
ocne
miu
s M
edia
lis
§ Re
ctus
Fem
oris
§
Vast
us L
ater
alis
This
pro
ject
was
sup
porte
d by
the
Tor
onto
Reh
abili
tatio
n In
stitu
te,
whi
ch r
ecei
ves
fund
ing
unde
r th
e P
rovi
ncia
l Reh
abili
tatio
n R
esea
rch
Pro
gram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io.
The
view
s ex
pres
sed
do n
ot n
eces
saril
y re
flect
thos
e of
the
Min
istry
.
Dev
elop
men
t of a
Sha
m C
ondi
tion
for
Futu
re W
hole
Bod
y Vi
brat
ion
Inte
rven
tion
Tria
ls
Ras
hidi
, Abd
olaz
im1,
2 ; A
lizad
eh- M
eghr
azi,
Mila
d1,2; M
asan
i, K
ei1 ;
Pop
ovic
, R. M
ilos1
,2; G
iang
rego
rio, L
ora1
,4 ; C
rave
n, C
athy
1,3
1 Tor
onto
Reh
abili
tatio
n In
stitu
te;
2 Uni
vers
ity o
f To
ront
o, IB
BM
E; 3
Uni
vers
ity o
f Tor
onto
, Dep
artm
ent o
f Med
icin
e 4 U
nive
rsity
of W
ater
loo,
Dep
artm
ent o
f Kin
esio
logy
Toro
nto
Reh
ab is
a te
achi
ng a
nd re
sear
ch h
ospi
tal f
ully
affi
liate
d w
ith th
e U
nive
rsity
of T
oron
to.
Bac
kgro
und
• P
lace
bo
effe
cts
are
be
defin
ed
as
the
posi
tive
phys
iolo
gica
l or
ps
ycho
logi
cal c
hang
es a
ssoc
iate
d w
ith t
he u
se o
f in
ert
med
icat
ions
, sh
am
proc
edur
es,
or
ther
apeu
tic
sym
bols
w
ithin
a
heal
thca
re
enco
unte
r. P
lace
bos
can
also
be
activ
e su
bsta
nces
or r
eal p
roce
dure
s th
at p
rodu
ce u
nexp
ecte
d be
nefic
ial e
ffect
s.
• In
ran
dom
ized
con
trol t
rials
usi
ng d
evic
e in
terv
entio
ns, i
t is
diffi
cult
to
crea
te
a co
mpa
rato
r or
co
ntro
l co
nditi
on
sim
ilar
enou
gh
to
the
inte
rven
tion
to b
e co
nsid
ered
an
appr
opria
te o
r va
lid c
ontro
l. Th
is is
th
ough
t by
man
y to
be
the
only
way
to m
inim
ize
the
effe
cts
of b
ias
on
reha
bilit
atio
n tri
al o
utco
mes
. •
Non
-dru
g in
terv
entio
ns
in
spin
al
cord
in
jury
(S
CI)
reha
bilit
atio
n re
sear
ch s
uch
as a
cupu
nctu
re,
mag
netic
fie
ld t
hera
py,
and
spec
ific
exer
cise
ther
apie
s le
nd th
emse
lves
bet
ter t
o th
e us
age
of a
pla
cebo
or
sham
con
ditio
n.
• W
hole
bod
y vi
brat
ion
(WB
V)
is a
new
and
nov
el
inte
rven
tion
whi
ch
has
rece
ived
atte
ntio
n in
SC
I res
earc
h fo
r the
trea
tmen
t of s
uble
sion
al
oste
opor
osis
, sa
rcop
enia
, ob
esity
, m
etab
olic
sy
ndro
me
and
card
iova
scul
ar d
isea
se.
• O
ur a
bilit
y to
det
erm
ine
the
effe
ctiv
enes
s of
reha
bilit
atio
n in
terv
entio
ns
in p
hase
III
& I
V t
rials
is
depe
nden
t up
on c
reat
ion
of v
alid
sha
ms/
cont
rol c
ondi
tions
.
Obj
ectiv
es
• Th
e pu
rpos
e of
this
stu
dy w
as to
dev
elop
a s
ham
WB
V c
ondi
tion.
•
We
soug
ht to
pro
duce
a d
evic
e w
hich
is id
entic
al in
app
eara
nce,
whi
le
repl
icat
ing
two
com
pone
nts
of t
he r
eal
devi
ce i
nclu
ding
mec
hani
cal
vibr
atio
n vi
a th
e ap
plic
atio
n of
vib
ratio
n to
the
par
ticip
ant's
upp
er
extre
miti
es, a
nd s
imila
r aud
itory
stim
uli d
urin
g op
erat
ion.
•
Our
a p
riori
aim
was
to fo
ol n
aïve
par
ticip
ants
50%
of t
he ti
me.
Prea
mbl
e •
A cu
stom
ized
WAV
E P
ro v
ibra
tion
plat
form
fitt
ed t
o an
Eas
ySta
nd
5000
sta
ndin
g fra
me
was
use
d. Q
ualit
ativ
e in
vest
igat
ion
of th
e de
vice
pr
evio
usly
con
duct
ed a
t ou
r ce
ntre
iden
tifie
d th
e m
ost
salie
nt s
timul
i re
sulti
ng fr
om e
xpos
ure:
•
Vest
ibul
ar
• A
udito
ry
• P
ropr
ioce
ptiv
e •
The
stud
y te
am a
ttem
pted
to
repl
icat
e th
ese
stim
uli
with
the
sha
m
devi
ce
Met
hods
1)
Sha
m D
evel
opm
ent
Vibr
atio
n R
eplic
atio
n •
Thre
e vi
brat
ion
setu
ps w
ere
test
ed to
repl
icat
e vi
brat
ion:
1)
Thre
e ga
min
g jo
y-st
ick
mot
ors
atta
ched
to th
e st
andi
ng fr
ame.
2)
Two
smal
l 3V
/1A
DC
mot
ors
conn
ecte
d un
der t
he p
latfo
rm.
3)
Five
sm
all
3V/1
A D
C m
otor
s w
ith 1
0g a
nd 1
5g o
ffset
wei
ghts
co
nnec
ted
unde
r pla
tform
and
to th
e st
andi
ng fr
ame.
So
und
Rep
licat
ion
• C
ompa
rison
s be
twee
n di
ffere
nt
soun
d re
cord
ers
&
smal
l si
ze
spea
kers
wer
e do
ne.
• W
e re
cord
ed t
he s
ound
of
the
vibr
atin
g pl
atfo
rm f
or r
epla
ying
and
“co
ntro
lling” th
e sh
am m
otor
s.
• A
soun
d sp
eake
r w
as p
lace
d un
der
the
vibr
atin
g pl
atfo
rm t
o m
imic
th
e lo
catio
n of
the
soun
d so
urce
. 2)
Eva
luat
ion
• Th
e sh
am d
evic
e w
ill b
e ev
alua
ted
by p
eopl
e w
ith S
CI
and
with
out
SC
I to
dete
rmin
e w
heth
er it
is a
con
vinc
ing
sham
. •
Par
ticip
ants
w
ill
be
expo
sed
to
two
min
utes
vi
brat
ion
or
sham
vi
brat
ion
sequ
entia
lly in
a c
ount
erba
lanc
ed d
esig
n.
• Q
uest
ionn
aire
s ga
ugin
g ce
rtain
ty o
f re
al v
ersu
s sh
am v
ibra
tion
will
be
adm
inis
tere
d. T
he ra
te o
f sha
m s
uffic
ienc
y w
ill b
e re
porte
d.
• A
n ad
ditio
nal q
uest
ionn
aire
will
inqu
ire a
bout
loud
ness
and
per
ceiv
ed
vibr
atio
n ge
nera
ted
acro
ss th
e tw
o co
nditi
ons.
•
Sta
ff ad
min
iste
ring
ques
tionn
aire
s &
par
ticip
ants
will
be
blin
ded
to
grou
p al
loca
tion
(sha
m o
r reg
ular
dev
ice)
dur
ing
data
col
lect
ion.
Figu
re
2.
Sch
emat
ic
of
the
mod
ified
vi
brat
ion
devi
ce t
o ge
nera
te t
he S
ham
co
nditi
on.
Res
ults
1)
Dev
ice
Dev
elop
men
t (Fi
gure
2)
• Th
e pr
ojec
t tea
m a
gree
d th
at th
e op
timal
sha
m s
etup
was
the
use
of
five
smal
l 3V
/1A
DC
mot
ors
incl
udin
g th
ree
on t
he f
ram
e w
ith 1
0g
wei
ghts
and
two
unde
r the
pla
tform
with
15g
offs
et w
eigh
ts (F
igur
e 1)
. •
A hi
gh d
efin
ition
rec
ordi
ng c
ondu
cted
in a
sou
nd d
ampe
ning
cha
mbe
r w
as u
sed
to g
ener
ate
a so
und
file
whi
ch w
as p
laye
d ba
ck u
sing
a
Bos
e S
ound
Doc
k P
orta
ble
Dig
ital M
usic
Sys
tem
. •
A ci
rcui
t w
as c
reat
ed t
o al
low
for
the
ind
epen
dent
adj
ustm
ent
and
initi
atio
n of
five
mot
ors
sim
ulta
neou
sly.
The
circ
uit w
as p
ower
ed a
5V
an
d 12
V D
C o
utpu
ts fr
om a
n AT
X c
ompu
ter p
ower
sup
ply
(Fig
ure
1).
2) E
valu
atio
n •
Qua
litat
ive
eval
uatio
n of
the
devi
ce is
pla
nned
Dis
cuss
ion
• A
prel
imin
ary
sham
pr
otot
ype
has
been
de
velo
ped.
P
lans
ar
e un
derw
ay to
pro
spec
tivel
y ev
alua
te th
e sh
am c
ondi
tion.
•
Lim
itatio
ns o
f the
cur
rent
pro
toty
pe in
clud
e:
Ø
Effe
cts
of th
e su
rrou
ndin
g en
viro
nmen
t on
the
soun
d re
cord
ing
Ø
The
audi
ble
diffe
renc
e be
twee
n th
e “re
cord
ed s
ound” a
nd t
he
“ac
tual
sou
nd” fr
om th
e ru
nnin
g vi
brat
ing
plat
form
Ø
The
soun
d th
at t
he s
mal
l vib
ratin
g m
otor
add
ed t
o th
e de
vice
is
audi
ble.
Ø
Sep
arat
e co
ntro
l in
terfa
ces
for
the
real
vib
ratio
n (o
rigin
al W
AVE
in
terfa
ce) a
nd s
ham
vib
ratio
n (c
usto
m c
ircui
t).
Ø
Furth
er r
efin
emen
ts t
o th
e sh
am d
evic
e ar
e pe
ndin
g qu
alita
tive
feed
back
.
Ack
now
ledg
emen
ts
• W
e ac
know
ledg
e fu
ndin
g fro
m th
e O
ntar
io N
euro
traum
a Fo
unda
tion
&
the
Min
istry
of H
ealth
and
Lon
g Te
rm C
are.
We
grat
eful
ly a
ckno
wle
dge
the
tech
nica
l ass
ista
nce
of E
gor S
anin
and
Elia
s G
uest
rin in
cre
atio
n of
th
e S
ham
Dev
ice.
Ref
eren
ces
Lind
e K
, et a
l. A
re th
e cl
inic
al e
ffect
s of
hom
eopa
thy
plac
ebo
effe
cts?
A m
eta-
anal
ysis
of p
lace
bo-
cont
rolle
d tri
als.
Lan
cet.
1997
Sep
20;
350(
9081
):834
-43.
D
iede
rich
NJ,
Goe
tz C
G. T
he p
lace
bo tr
eatm
ents
in N
euro
scie
nces
: new
insi
ghts
from
clin
ical
and
ne
uroi
mag
ing
stud
ies.
Neu
rolo
gy 2
008;
71:6
77–6
84.
1 To
ront
o R
ehab
2
Uni
vers
ity o
f Tor
onto
3
Wat
erlo
o U
nive
rsity
Figu
re 1
. Circ
uit b
oard
con
trolli
ng th
e fiv
e sh
am m
otor
s si
mul
tane
ousl
y (le
ft).
Mot
or
with
offs
et w
eigh
t to
gen
erat
e th
e sh
am
vibr
atio
n (r
ight
).
Reh
ab
ilit
ati
on
En
gin
ee
rin
g L
ab
ora
tory
Inst
itu
te o
f B
iom
ate
ria
ls a
nd
Bio
me
dic
al
En
gin
ee
rin
g, U
niv
ers
ity
of
To
ron
toT
oro
nto
Reh
ab
ilit
ati
on
In
stit
ute
Co
nta
ct:
dim
itry
.sayenko@
uto
ronto
.ca
ww
w.t
oro
nto
-fes.
ca
Pa
rtn
ers
:
Ca
na
dia
n I
nsti
tute
s o
f H
ea
lth
Re
se
arc
h
Inst
itu
tsd
e re
che
ree
n s
an
téd
u C
an
ad
a
Ca
na
dia
n I
nsti
tute
s o
f H
ea
lth
Re
se
arc
h
Inst
itu
tsd
e re
che
ree
n s
an
téd
u C
an
ad
a
Na
tura
l S
cie
nces a
nd
En
gin
ee
rin
g R
ese
arc
h C
ou
ncil
of
Ca
na
da
Co
nseil
de
rech
erc
he
se
n s
cie
nce
s n
atu
rell
ese
t e
n gén
ied
u C
an
ad
a
Na
tura
l S
cie
nces a
nd
En
gin
ee
rin
g R
ese
arc
h C
ou
ncil
of
Ca
na
da
Co
nseil
de
rech
erc
he
se
n s
cie
nce
s n
atu
rell
ese
t e
n gén
ied
u C
an
ad
a
Min
istr
y o
f H
ea
lth
an
d L
on
g T
erm
Care
Min
istr
y o
f H
ea
lth
an
d L
on
g T
erm
Care The v
iew
s exp
ress
ed in t
his
post
er
do n
ot
nece
ssarily
reflect
th
ose
of
any o
f th
e g
ranting a
genci
es.
BIL
AT
ER
AL S
OLE
US
HB
ILA
TE
RA
L S
OLE
US
H-- R
EFLE
XE
S I
N H
UM
AN
S D
UR
ING
SIT
TIN
G
RE
FLE
XE
S I
N H
UM
AN
S D
UR
ING
SIT
TIN
G
AN
D P
AS
SIV
E S
TA
ND
ING
: V
AR
IAB
ILIT
Y A
ND
CO
RR
ELA
TIO
N
AN
D P
AS
SIV
E S
TA
ND
ING
: V
AR
IAB
ILIT
Y A
ND
CO
RR
ELA
TIO
N
DG
Sa
ye
nk
o1,
K M
asa
ni1
, M
R P
op
ovic
1,2
1–
Toro
nto
Rehabili
tation I
nst
itute
; 2
–U
niv
ers
ity
of
Toro
nto
INT
RO
DU
CT
ION
Th
e ra
nd
om
flu
ctu
atio
n in
H
-re
flex am
plit
ud
e h
as b
ee
n
stu
die
d p
revio
usly
to u
nd
ers
tan
d its
ch
ara
cte
ristics a
nd o
rigin
s
[Nozaki
et
al.,
19
95
]. I
t h
as b
ee
n s
ug
geste
d t
ha
t su
pra
spin
al
ce
nte
rs
co
ntr
ibu
te
to
the
co
rre
latio
n
in
bila
tera
l H
-re
fle
x
thro
ug
h
pre
- a
nd
/or
posts
yn
ap
tic
inhib
itio
n
[No
zaki
et
al.,
19
96
]. To
in
ve
stig
ate
th
e
co
ntr
ibu
tio
n
of
pre
syn
ap
tic
an
d
po
sts
yn
ap
tic m
ech
an
ism
s i
n t
he
va
ria
bili
ty a
nd
co
rre
latio
n o
f
bila
tera
l H
-refle
xes,
we e
xam
ine
d t
he H
-re
fle
xes i
n b
oth
le
gs
duri
ng d
iffe
ren
t co
nditio
ns:
sittin
g a
nd
passiv
e s
tan
din
g.
Be
ca
use
th
e H
-re
fle
x i
s i
nh
ibite
d i
n s
tan
din
g p
ostu
re d
ue
to s
upra
spin
al
inp
ut
via
pre
syn
ap
tic i
nhib
itio
n [
Koseja
et
al.,
19
93
], w
e h
yp
oth
esiz
ed t
ha
t th
e r
eflex m
ag
nitu
de w
ill v
ary
in
sittin
g
an
d
sta
nd
ing
, w
he
rea
s
its
va
ria
bili
ty
will
n
ot
sh
ow
sig
nific
an
t d
iffe
ren
ce
in
d
iffe
ren
t p
ostu
res.
Fu
rth
er,
if
the
su
pra
sp
inal
ce
nte
rs a
re i
nvolv
ed
in
co
rre
latio
n o
f b
ilate
ral
H-
refle
x r
esp
onses t
hro
ug
h p
resyn
ap
tic m
ech
anis
ms,
the
n th
is
corr
ela
tio
n m
ay d
ep
en
d o
n t
he p
ostu
re.
ME
TH
OD
S
PA
RT
ICIP
AN
TS
: Eig
ht
able
-bodie
d volu
nte
ers
(2
fe
male
s, 6 m
ale
s),
20-4
0 y
ears
old
PO
SIT
ION
S:
Sitting
and
Pass
ive
standin
g
in
“Easy
Sta
nd
5000”
(Altim
ate
Medic
al, I
nc.
, U
SA)
H-R
EFLE
X:
60 s
ole
us
H-r
eflexes
were
evoked in
right
and le
ft le
gs
sim
ultaneousl
y
with inte
rstim
uli
inte
rval of
5 s
.
RE
SU
LT
S
1.
The m
agnitude o
f th
e H
-reflex w
as
smalle
r during p
ass
ive
standin
g in c
om
pariso
n w
ith s
itting:
19.0
±9.8
% v
s. 3
6.3
±4.6
%
of
the
sole
us
maxim
al
M-w
ave
(Mm
ax) ,
resp
ect
ively
(p =
0.0
04).
2.
There
w
as
no si
gnific
ant
diffe
rence
in
th
e co
eff
icie
nt
of
variation d
uring s
itting a
nd p
ass
ive s
tandin
g:
11.7
±5.3
vs.
15.4
±9.2
%, re
spect
ively
.
3.
There
w
as
no
signific
ant
diffe
rence
in
th
e
corr
ela
tion
coeff
icie
nt
during s
itting a
nd p
ass
ive s
tandin
g:
0.6
2 ±
0.1
6
vs.
0.5
9 ±
0.2
0, re
spect
ively
.
1.
Th
ese
re
su
lts
co
ncu
r w
ith
p
rio
r re
po
rts
tha
t
sig
nif
ica
nt
inh
ibit
ion
of
the
so
leu
s H
-re
fle
x o
ccu
rs
wh
en
ch
an
gin
g p
ostu
re f
rom
sit
tin
g t
o s
tan
din
g.
2.
Ou
r re
su
lts s
up
po
rt t
he
fin
din
gs t
ha
t p
osts
yn
ap
tic
bu
t n
ot
pre
syn
ap
tic m
ech
an
ism
s a
re p
red
om
ina
nt
in t
he
va
ria
bil
ity o
f th
e m
on
osyn
ap
tic r
efl
ex
.
3.
Th
e l
eve
l o
f co
rre
lati
on
of
bil
ate
ral
H-r
efl
ex
did
no
t
de
pe
nd
on
th
e p
ostu
re s
ug
ge
sti
ng
th
at
pre
syn
ap
tic
me
ch
an
ism
s
are
n
ot
the
le
ad
ing
fa
cto
r in
th
is
ph
en
om
en
on
.
CO
NC
LU
SIO
N
1.
Nozaki D
, N
akazaw
a K
, Y
am
am
oto
Y.
Fra
cta
l corr
ela
tion in h
um
an
H-r
efle
x.
Exp
Bra
in R
es 1
99
5;1
05
:402
-10
.
2.
Nozaki
D,
Nakazaw
a K
, Y
am
am
oto
Y.
Supra
spin
al
eff
ects
on t
he
fracta
l corr
ela
tion in h
um
an H
-reflex.
Exp B
rain
Res 1
996;1
12:1
12-
8.
3.
Koceja
D
M,
Trim
ble
M
H,
Ea
rles D
R.
Inh
ibitio
n o
f th
e sole
us H
-
refle
x in
sta
ndin
g m
an
. B
rain
Res 1
99
3;6
29
:155
-8.
RE
FE
RE
NC
ES
68
7.2
5
Pa
rtic
ipa
nt
F:
So
leu
s H
- re
fle
x d
uri
ng
sit
tin
g
Pa
rtic
ipa
nt
F:
So
leu
s H
- re
fle
x d
uri
ng
pa
ssiv
est
an
din
g
Tri
al
H-reflex amplitude, mV
Tri
al
Correlation coefficient
Pa
rtic
ipa
nt
Coefficient of variance
Pa
rtic
ipa
nt
Pa
rtic
ipa
nt
Coefficient of variance
Pa
rtic
ipa
nt
Pa
rtic
ipa
nt
Pa
rtic
ipa
nt
Le
ftR
igh
t
refl
ex
du
rin
g s
itti
ng
Tri
al
sta
nd
ing
Tri
al
Reh
ab
ilit
ati
on
En
gin
eeri
ng
Lab
ora
tory
Inst
itu
te o
f B
iom
ate
ria
ls a
nd
Bio
med
ica
l E
ng
inee
rin
g, U
niv
ers
ity
of
To
ron
toT
oro
nto
Re
ha
bil
ita
tio
n I
nst
itu
teC
on
tact
:dim
itry
.sayenko@
uto
ronto
.ca
ww
w.t
oro
nto
-fe
s.ca
Pa
rtn
ers
:
Ca
na
dia
n I
nsti
tute
s o
f H
ea
lth
Re
se
arc
hIn
sti
tuts
de
re
ch
ere
en
sa
nté
du
Ca
nad
aC
an
ad
ian
In
sti
tute
s o
f H
ea
lth
Re
se
arc
hIn
sti
tuts
de
re
ch
ere
en
sa
nté
du
Ca
nad
aN
atu
ral
Scie
nce
s a
nd
En
gin
ee
rin
g R
ese
arc
h C
ou
ncil
of
Ca
nad
aC
on
se
ild
e r
ech
erc
he
se
n s
cie
nces n
atu
rell
es
et
en
gén
ied
u C
an
ad
aN
atu
ral
Scie
nce
s a
nd
En
Na
tura
l S
cie
nce
s a
nd
En
Na
tura
l S
cie
nce
s a
nd
En
Na
tura
l S
cie
nce
s a
nd
Eng
ine
eri
ng
Re
se
arc
h C
ou
ng
ine
eri
ng
Re
se
arc
h C
ou
nN
atu
ral
Scie
nce
s a
nd
En
gin
ee
rin
g R
ese
arc
h C
ou
ncil
of
Ca
nad
aC
on
se
ild
e r
ech
erc
he
se
n s
cie
nces n
atu
rell
es
et
en
gén
ied
u C
an
ad
a
Min
istr
y o
f H
ea
lth
a
nd
Lo
ng
Te
rm C
are
Min
istr
y o
f H
ea
lth
a
nd
Lo
ng
Te
rm C
are T
he v
iew
s expre
ssed in t
his
post
er
do n
ot
nece
ssarily
reflect
th
ose
of
any
of
the g
ranting a
genci
es.
EFFE
CT
S O
F V
OLU
NT
AR
Y E
XE
RC
ISE
, FU
NC
TIO
NA
L E
LE
CT
RIC
AL S
TIM
ULA
TIO
NE
FFE
CT
S O
F V
OLU
NT
AR
Y E
XE
RC
ISE
, FU
NC
TIO
NA
L E
LE
CT
RIC
AL S
TIM
ULA
TIO
N
AN
D V
IBR
AT
ION
ON
CO
RT
ICO
MU
SC
ULA
R C
OH
ER
EN
CE
A
ND
VIB
RA
TIO
N O
N C
OR
TIC
OM
US
CU
LA
R C
OH
ER
EN
CE
S
aye
nk
o D
G1,
Ma
sa
ni
K1,
Gri
go
rovsk
y V
2,
Po
po
vic
MR
1,2
1–
Toro
nto
Rehabili
tation I
nst
itute
;2
–U
niv
ers
ity
of
Toro
nto
INT
RO
DU
CT
ION
Ne
w f
indin
gs i
n t
he f
ield
of
adaptive n
euro
pla
sticity h
ave d
em
onstr
ate
d
that
goal-oriente
d
exerc
ises
couple
d
with
neuro
muscula
r ele
ctr
ical
stim
ula
tion o
r vib
ration m
ay p
rom
ote
im
pro
ve
me
nt
of
vo
lun
tary
mu
scle
contr
ol
and fu
nctional
abili
ties [1
, 2
, 3
]. H
ow
eve
r, th
e p
hysio
log
ical
me
ch
an
ism
s u
nd
erlyin
g t
he
ob
se
rve
d b
en
efits
of
the
su
pp
lem
en
tary
se
nso
rim
oto
r stim
ula
tio
n h
ave
no
t b
een investigate
d in d
eta
il.
In t
he c
urr
ent
stu
dy,
we a
imed t
o i
nvestigate
the c
entr
al
effects
of
the
sensorim
oto
r stim
ula
tion o
n t
he i
nte
raction b
etw
een
cort
icospin
al
drive
and s
pin
al
moto
neuro
nes.
It i
s b
elie
ved t
hat
incre
ased c
ort
icom
uscula
r
cohere
nce can re
flect
a tighte
r cort
ical
contr
ol
of
the m
uscle
activity
during t
he a
cquis
itio
n o
f th
e m
oto
r ta
sk [
4].
1.
Popo
vic
MR
et
al. F
unctiona
l e
lectr
ica
l stim
ula
tion
fo
r gra
sp
ing a
nd
wa
lkin
g:
ind
ica
tion
s a
nd
limita
tion
s. S
pin
al C
ord
. 2001
;39:4
03
-12
.
2.
Ru
sh
ton D
N.
Fun
ctiona
l e
lectr
ica
l stim
ula
tion
and
re
hab
ilita
tion
--an
hypoth
esis
. M
ed
Eng
Ph
ys. 200
3;2
5:7
5-8
.
3.
Ca
rdin
ale
M,
Bo
sco
C.
The
use
of
vib
ration
as a
n e
xe
rcis
e i
nte
rven
tion
. E
xe
rc S
po
rt S
ci
Re
v.
2003
;31
:3-7
.
4.
Pe
rez M
A e
t a
l. C
hange
s in
co
rtic
osp
ina
l d
rive
to
sp
ina
l m
oto
neuro
ne
s f
ollo
win
g vis
uo
-
mo
tor
skill
lea
rnin
g in h
um
ans. J P
hysio
l. 2
006
;57
3:8
43
-55
RE
FE
RE
NC
ES
74
.19
RE
SU
LT
S
2.
EE
G-E
MG
co
he
ren
ce
sig
nif
ica
ntl
y
incre
ase
d
aft
er
FE
S
an
d
VO
L+
FE
S.
The v
alu
es
are
pre
sente
d a
s perc
enta
ges
of
the
cohere
nce
are
a
obta
ined
prior
to
each
experim
enta
l co
nditio
n.
EEG-EMG coherenceafter experimental conditions
(% of initial values)
PU
RP
OS
ET
o
investigate
w
he
ther
the
som
ato
sensory
stim
ula
tio
n
caused
by
neuro
muscula
r ele
ctr
ical
stim
ula
tion
or
vib
ration
can
pote
ntiate
cort
icom
uscula
r couplin
g d
uring v
olu
nta
ry m
ovem
ent.
ME
TH
OD
SParticipants
: F
ive a
ble
-bodie
d v
olu
nte
ers
(2 fem
ale
s,
3 m
ale
s).
Conditions:
inte
rmedia
te 1
s d
ors
ifle
xio
n a
nd r
est periods d
uring 1
0 m
in:
- vo
lun
tary
mo
vem
ents
at th
e le
ve
l of 1
5%
of
MV
C (
VO
L15
);
- vo
lun
tary
mo
vem
ents
at th
e le
ve
l of 7
% o
f M
VC
(V
OL
7);
- F
ES
driven
mo
vem
ents
at
the
le
ve
l of
7%
of
MV
C (
FE
S);
- vo
lun
tary
mo
vem
ents
at th
e le
ve
l of 7
% o
f M
VC
supp
lem
en
ted
with
FE
S a
t th
e le
ve
l of
7%
of
MV
C (
VO
L+
FE
S);
- vo
lun
tary
mo
vem
ents
at th
e le
ve
l of 1
5%
of
MV
C s
upp
lem
en
ted
with
con
sta
nt
vib
ration
(V
OL
+V
ibro
).
Tests
: w
ere
perf
orm
ed b
efo
re a
nd a
fter
the e
xperim
enta
l conditio
ns,
during 1
min
isom
etr
ic d
ors
ifle
xio
n a
t th
e level of
15%
of M
VC
.
EEG
: C
z a
nd 5
cm
late
ral to
Cz.
EMG
: m
. tibia
lis a
nte
rior.
FES
: fr
equency 4
0 H
z,
puls
e 2
50
s.
Vibration
: fr
equency 6
0 H
z,
am
plit
ude 1
mm
.
s. m
m.
EE
G e
lectr
od
es
Vis
ua
l fe
ed
ba
ck
FE
S e
lectr
od
es
EM
G e
lectr
od
es
[V] [V] [Nm]
Red d
ash
ed l
ine i
ndic
ate
s th
e r
equest
ed
level of
dors
ifle
xio
n d
uring t
he t
est
“Ste
ady t
orq
ue m
ain
tenance
”fo
r th
e a
naly
sis
(5 s
aft
er
initia
tion o
f th
e d
ors
ifle
xio
n)
1.
Mo
tor
task
pe
rfo
rma
nce
incre
ase
d a
fte
r V
OL7
, FE
S,
VO
L+
FE
S.
The
valu
es
are
pre
sente
d as
perc
enta
ges
of
the s
tandard
devia
tion v
alu
es
obta
ined
prior
to
each
experim
enta
l co
nditio
n.
Test performanceafter experimental conditions
(% of initial values)
CO
NC
LU
SIO
N1.
Supple
menta
ry se
nso
ry st
imula
tion during goal-oriente
d exerc
ise ca
n re
sult in
cort
ical
reorg
aniz
ation and m
axim
ize tr
ansm
issi
on eff
ect
iveness
of
desc
endin
g
moto
r co
mm
ands.
2.
Contr
ibution
of
the
mech
anis
ms
underlin
ing
th
e
obse
rved
eff
ect
sw
ill
be
dete
rmin
ed in futu
re r
esearc
h.
PO
SS
IBLE
ME
CH
AN
ISM
I
Repetitive a
ntidro
mic
activation o
f th
e m
oto
rneuro
ns
enhanced r
ecru
itm
ent
of th
e m
oto
rneuro
ns (
thro
ugh
Hebb s
ynpses)
[2].
PO
SS
IBLE
ME
CH
AN
ISM
II
Repetitive p
eriphera
l nerv
e s
tim
ula
tion e
nhanced th
e e
xcitabili
ty o
f th
e
cort
ical pro
jections o
f corr
espondin
g m
uscle
s a
nd im
pro
ve m
oto
r
perf
orm
ance [3].
DIS
CU
SS
ION
PURP
OSE
PURP
OSE
CO
NC
LUSI
ON
CO
NC
LUSI
ON
Resp
onse
of In
divid
ual M
uscle
s to N
euro
mus
cular
Elec
trica
l Stim
ulat
ion T
rain
ig of
Kne
e Ext
enso
rs
1) T
o id
entif
y th
e un
ique
forc
e ve
ctor
pro
duce
d by
indi
vidu
al k
nee
exte
nsor
s2)
To
inve
stig
ate
the
cont
ribut
ion
of in
divi
dual
kne
e ex
tens
ors
to th
e fo
rce
vect
ors
prod
uced
by
the
glob
al s
timul
atio
n in
neu
rom
uscu
lar s
timul
atio
n tra
inin
g.
- Eac
h kn
ee e
xten
sor h
as a
uni
que
forc
e ve
ctor
.- D
istin
ct c
ontri
butio
ns fr
om in
divi
dual
mus
cles
wer
e fo
und,
sug
gest
ing
that
NM
S tra
inin
g m
ay
unev
enly
affe
ct k
nee
exte
nsor
s.
Partn
ers:
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
y,
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
Toro
nto
Reh
abili
tatio
n In
stitu
teC
onta
ct: k
.mas
ani@
utor
onto
.ca
web
pag
e: h
ttp:
//ww
w.to
ront
o-fe
s.ca
Subj
ects
: - Y
oung
hea
lthy
subj
ects
: n =
6 (a
ll m
ales
), 30
,0±8
.9 y
rsSt
imul
atio
n Lo
catio
ns:
- Vas
tus
med
ialis
(VM
), Va
stus
late
ralis
(VL)
, Rec
tus
fem
oris
(RF)
- Thr
ee g
loba
l loc
atio
ns o
n kn
ee e
xten
sors
; GS1
, GS2
, and
GS3
Mea
sure
men
ts:
- 3D
forc
e ex
ertio
n at
the
ankl
e jo
int u
sing
a fo
rce
sens
or (K
istle
r 906
7) m
ount
ed o
n a
cust
om m
ade
devi
ce (N
ozak
i et a
l. 20
05)
Prot
ocol
:- T
he s
ubje
ct s
at o
n th
e ch
air w
ith k
nee
and
hip
flexe
d at
90
degr
ee.
- A m
otor
poi
nt fo
r eac
h m
uscl
e w
as in
divi
dual
ly s
timul
ated
with
the
max
imal
, com
forta
bly
tole
rabl
e ite
nsity
, in
the
isom
etric
con
ditio
n.- G
S1-3
wer
e al
so s
timul
ated
.A
naly
sis:
- The
uni
t for
ce v
ecto
rs w
ere
calc
ulat
ed fo
r ind
ivid
ual m
uscl
es a
nd fo
r GS1
-3, u
sing
pr
inci
ple
com
pone
nt a
naly
sis.
- The
rela
tive
cont
ribut
ion
of in
divi
dual
mus
cles
to G
S1-3
was
est
imat
ed b
ased
on
an
assu
mpt
ion
that
the
forc
e ve
ctor
mea
sure
d du
ring
each
GS
was
a li
near
vec
tor s
umm
atio
n of
forc
e ve
ctor
s of
the
thre
e in
divi
dual
mus
cles
.
Met
hods
AB
STR
AC
TA
BST
RA
CT
Exam
ples
of r
ecor
ding
s1
Uni
t vec
tor f
or e
ach
mus
cle
stim
ulat
ion
and
GS
4
Ref
eren
ces
[1] B
otte
r A, e
t al.
Atla
s of
the
mus
cle
mot
or p
oint
s fo
r the
low
er li
mb:
impl
icat
ions
for e
lect
rical
st
imul
atio
n pr
oced
ures
and
ele
ctro
de p
ositi
onin
g. E
ur J
App
l Phy
siol
, 111
: 246
1–24
71, 2
011.
[2] N
ozak
i D
, et a
l.. U
ncer
tain
ty o
f kne
e jo
int m
uscl
e ac
tivity
dur
ing
knee
join
t tor
que
exer
tion:
the
sign
ifica
nce
of c
ontro
lling
adja
cent
join
t tor
que.
J A
ppl P
hysi
ol 9
9: 1
093–
1103
, 200
5.
Mas
ani K
1,2)
, Ali
S. H
assa
n 1,2)
, Say
enko
DG
1,2)
, Dai
chi N
ozak
i 3) , P
opov
ic M
R1,
2), s
pons
ored
by
Shin
ohar
a M
FAC
SM1)
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
, Tor
onto
, CAN
ADA
2) L
yndh
urst
Cen
tre,
Tor
onto
Reh
abili
tatio
n In
stitu
te, T
oron
to, C
ANAD
A 3)
Gra
duat
e Sc
hool
of E
duca
tion,
Uni
vers
ity o
f Tok
yo, T
okyo
, JAP
AN
AC
SM 2
012
San
Fran
cisc
o, C
A, M
ay 1
2 - J
une
2, 2
012
e-m
ail :
k.m
asan
i@ut
oron
to.c
a
N
euro
mus
cula
r ele
ctric
al s
timul
atio
n (N
MS)
is o
ne o
f the
mos
t pop
ular
adv
ance
d m
etho
dolo
gies
for a
thle
tes
to
gain
mus
cle
stre
ngth
. U
sual
ly, N
MS
uses
a p
air
of l
arge
ele
ctro
des
to s
timul
ate
one
mus
cle
grou
p (G
roup
St
imul
atio
n, G
S) in
stea
d of
stim
ulat
ing
indi
vidu
al m
uscl
es. T
o de
sign
effe
ctiv
e tra
inin
g pr
otoc
ols,
the
cont
ribut
ion
of
indi
vidu
al m
uscl
e to
GS
mus
t be
exam
ined
. Pur
pose
: 1) T
o id
entif
y th
e un
ique
forc
e ve
ctor
pro
duce
d by
indi
vidu
al
knee
ext
enso
rs, a
nd 2
) to
inve
stig
ate
the
cont
ribut
ion
of in
divi
dual
kne
e ex
tens
ors
to th
e fo
rce
vect
ors
prod
uced
by
GS
in N
MS
train
ing.
Met
hods
: Six
sub
ject
s (3
0.0±
8.9
yrs)
sat
on
a ch
air a
nd th
ree
knee
ext
enso
rs (v
astu
s m
edia
lis,
vast
us l
ater
alis
, an
d re
ctus
fem
oris
) w
ere
indi
vidu
ally
stim
ulat
ed. A
dditi
onal
ly, k
nee
exte
nsor
s w
ere
stim
ulat
ed
sim
ulta
neou
sly
as a
gro
up u
sing
con
vent
iona
l NM
S el
ectro
des
at th
ree
diffe
rent
loca
tions
(GS1
-3).
The
unit
forc
e ve
ctor
s in
the
isom
etric
con
ditio
n w
ere
calc
ulat
ed fo
r ind
ivid
ual m
uscl
es a
nd fo
r GS1
-3. T
he re
lativ
e co
ntrib
utio
n of
in
divi
dual
mus
cles
to G
S1-3
was
est
imat
ed b
ased
on
an a
ssum
ptio
n th
at th
e fo
rce
vect
or m
easu
red
durin
g ea
ch G
S w
as a
line
ar v
ecto
r sum
mat
ion
of fo
rce
vect
ors
of th
e th
ree
indi
vidu
al m
uscl
es. R
esul
ts: T
he u
nit f
orce
vec
tor w
as
stat
istic
ally
diff
eren
t am
ong
the
thre
e kn
ee e
xten
sors
(M
ANO
VA,
p <
0.00
1). T
he c
ontri
butio
n of
the
thr
ee k
nee
exte
nsor
s to
the
GS
was
sta
tistic
ally
diff
eren
t am
ong
the
thre
e kn
ee e
xten
sors
(MAN
OVA
, p =
0.0
4). C
oncl
usio
n:
Each
kne
e ex
tens
or h
as a
uni
que
forc
e ve
ctor
. Dis
tinct
con
tribu
tions
from
indi
vidu
al m
uscl
es w
ere
foun
d, s
ugge
stin
g th
at N
MS
train
ing
may
une
venl
y af
fect
kne
e ex
tens
ors.
- The
forc
e ve
ctor
s w
ere
diffe
rent
am
ong
the
mea
sure
d th
ree
mus
cles
.- T
he fo
rce
vect
or o
f GS
was
with
in th
e 3D
sp
ace
shap
ed b
y th
e m
easu
red
thre
e m
uscl
es.
Inde
pend
ency
of f
orce
vec
tor t
o fo
rce
leve
l2
- Exa
mpl
es o
f thr
ee fo
rce
leve
ls fo
r VL
stim
ulat
ion
(left)
, and
forc
e di
rect
ions
for e
ach
mea
sure
d m
uscl
e in
clud
ing
thre
e fo
rce
leve
ls
resp
ectiv
ely.
- The
forc
e ve
ctor
for e
ach
mus
cle
appe
ars
sim
ilar a
mon
g di
ffere
nt fo
rce
leve
ls.
Con
trib
utio
n of
eac
h m
uscl
e on
GS
5
4.8
6
-30
190.
5 0
0.5 -1
VMVL
RF
0.5 0
0.5 -1
GS1
GS2
GS3
1
0.8
0.6
0.4
0.2 0
VMVL
RF
Con
tribu
tion
of e
ach
mus
cle
to G
S
Uni
t Vec
tor f
orea
ch m
uscl
e st
imul
atio
nU
nit V
ecto
rfo
r GS
A
200m
m
70m
m
120m
m
40m
m
Foot
Pla
te
Foot
Pla
teFo
ot P
late
Forc
e Se
nsor
Bear
ing
B
DC
Forc
e m
easu
rem
ent s
yste
m. A
: sub
ject
se
ated
on
a ch
air w
ith th
e rig
ht fo
ot
plac
ed o
n a
forc
e m
easu
rem
ent d
evic
e.
The
low
er le
g w
as s
et to
be
verti
cal.
The
right
foot
was
firm
ly fi
xed
to th
e de
vice
by
a st
rap.
Top
(B),
side
(C),
and
front
(D)
view
s of
the
forc
e m
easu
rem
ent
devi
ce.T
he tr
iaxi
al fo
rce
sens
or m
ount
ed
just
bel
ow th
e ro
tatio
n ax
is c
an m
easu
re
the
forc
e th
at th
e su
bjec
t exe
rts a
t the
an
kle
join
t pos
ition
.
VMVL
RF
100
ms
GS1
15 -15 2.4
-14
-1.2
3
15 -15 2.
4
-14
-1.2
3
15 -15 2.4
-14
-1.2
3
VM M
otor
Poi
ntVL
Mot
or P
oint
RF
Mot
or P
oint
GS G
S1: 3
cm
Med
ial
GS2
: Mid
dle
GS3
: 3 c
m L
ater
al
M-L
A-P
Verti
cal
Forc
eD
irect
ion
M-L
A-P
Verti
cal
Forc
eD
irect
ion
VLFo
rce
Leve
l 1VL
Forc
e Le
vel 2
VLFo
rce
Leve
l 3<
<
M-L
A-P
Verti
cal
Forc
e D
irect
ion
M-L
A-P
Verti
cal
Forc
e D
irect
ion
- The
con
tribu
tion
of th
e th
ree
knee
ext
enso
rs w
as s
tatis
tical
ly d
iffer
ent a
mon
g th
e th
ree
knee
ext
enso
rs (M
ANO
VA, p
= 0
.04)
.- W
hen
the
glob
al s
timul
atio
n w
as a
pplie
d, e
ach
mus
cle
was
stim
ulat
ed w
ith a
diff
eren
t lev
el.
The
view
s ex
pres
sed
in th
s po
ster
do
not n
eces
saril
y re
flect
thos
e of
any
of t
he g
rant
ing
agen
cies
.
The
auth
ors
appr
ecia
te M
s. T
omoy
o H
iraba
yash
i for
hel
ping
the
expe
rimen
t and
ana
lysi
s.
The
auth
ors
ackn
owle
dge
the
supp
ort o
f Tor
onto
Reh
abilit
atio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he
Prov
inci
al R
ehab
ilitat
ion
Res
earc
h Pr
ogra
m fr
om th
e M
inis
try o
f Hea
lth a
nd L
ong-
Term
Car
e in
Ont
ario
.M-L
A-P
Verti
cal
3D fo
rce
mea
sure
men
tve
ctor
calc
ulat
ion
10 N
-1.2
-30
Anod
e El
ectro
de
100
ms
GS1
GS2
GS3
Diff
eren
ce o
f for
ce v
ecto
r am
ong
GS1
- 3
3
3
-18 6
-24
-0.6
4.8
M-L
A-P
Verti
cal
Forc
eD
irect
ion
10 N
- The
forc
e ve
ctor
s of
thre
e G
Ss (G
S1-G
S3) w
ere
sim
ilar b
ut s
light
ly d
iffer
ent.
- The
uni
t for
ce v
ecto
r was
sta
tistic
ally
diff
eren
t am
ong
the
thre
e kn
ee e
xten
sors
(MAN
OVA
, p
< 0.
001)
.- T
he m
easu
red
thre
e m
uscl
es e
xerte
d fo
rce
in
diffe
rent
dire
ctio
ns.
- The
uni
t for
ce v
ecto
r was
not
sta
tistic
ally
di
ffere
nt a
mon
g th
e th
ree
GSs
(MAN
OVA
, p
= 0.
840)
.- C
onsi
dera
bly
diffe
rent
pat
tern
s am
ong
the
subj
ects
mig
ht c
ause
this
insi
gnifi
cant
resu
lt.
Uni
t Vec
tor 1
(UV1
)
Uni
t Vec
tor 2
(UV2
)
αU
V1
βUV2
GS
Vect
or (G
S)
Con
tribu
tion
of U
V1=
|α|
|α| +
|β|
Con
tribu
tion
of U
V2=
|β|
|α| +
|β|
GS1
GS2
GS3
100
ms
2 N
PURP
OSE
PURP
OSE
CO
NC
LUSI
ON
CO
NC
LUSI
ON
To i
nves
tigat
e th
e fe
asib
ility
of r
educ
ing
mus
cle
fatig
ue b
y di
strib
utin
g th
e el
ectri
c fie
ld o
ver
a w
ider
are
a us
ing
mul
tiple
su
rface
ele
ctro
des
plac
ed o
ver t
he m
uscl
e
- The
effe
ctiv
enes
s of
usi
ng S
DSS
in p
lant
er fl
exor
s to
redu
ce m
uscl
e fa
tigue
was
sho
wn
in o
ne
indi
vidu
al w
ith S
CI a
nd a
ble-
bodi
ed in
divi
dual
s.- T
he re
sults
war
rant
the
pote
ntia
l of S
DSS
to p
rolo
ng tr
aini
ng s
essi
ons
of F
ES th
erap
y.
Partn
ers:
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
y,
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
Toro
nto
Reh
abili
tatio
n In
stitu
teC
onta
ct: k
.mas
ani@
utor
onto
.ca
web
pag
e: h
ttp:
//ww
w.to
ront
o-fe
s.ca
Subj
ects
: - A
n in
divi
dual
with
com
plet
e SC
I, T3
/T4,
ASI
A A,
4 y
ears
pos
t inj
ury
Task
: - I
som
etric
, con
tinuo
us p
lant
ar fl
exio
n in
a s
ittin
g po
stur
e fo
r 2 m
in- C
ompa
rison
bet
wee
n SE
S an
d SD
SS (s
ee th
e rig
ht c
olum
n)- 1
2 tri
als
in s
epar
ated
day
s (6
SES
and
6 S
DSS
)- F
ES: P
ulse
freq
uenc
y, 40
Hz;
Pul
se w
idth
, 250
us;
Pul
se in
tens
ity, 6
4±5
mA
(SES
) and
51±
4 m
A (S
DSS
)M
easu
rem
ents
:- P
lant
er fl
exio
n to
rque
Ana
lysi
s:- F
atig
ue In
dex
(FI):
Tor
que
at th
e en
d of
the
2 m
in s
timul
atio
n no
rmal
ized
to th
e m
axim
um
torq
ue- F
atig
ue T
ime
(FT)
: Diff
eren
ce in
tim
e fro
m w
hen
the
max
imum
torq
ue w
as a
chie
ved
to
whe
n th
e th
e to
rque
dro
pped
by
3 dB
- Tor
que-
Tim
e In
tegr
al (T
TI):
Inte
gral
of t
orqu
e ov
er th
e en
tire
2 m
in fa
tigui
ng s
timul
atio
n
Expe
rimen
t 1
BA
CK
GR
OU
ND
BA
CK
GR
OU
ND
Pa
tient
s w
ith n
euro
logi
cal d
isor
ders
suc
h as
spi
nal c
ord
inju
ry (S
CI),
stro
ke, a
nd tr
aum
atic
bra
in in
jury
, fre
quen
tly
suffe
r fro
m m
otor
dis
abilit
y. M
otor
dis
abilit
y de
tract
s fro
m p
atie
nts’
inde
pend
ence
and
the
refo
re q
ualit
y of
life
. Ad
ditio
nally
, mot
or d
isab
ility
caus
es d
isus
e of
mus
cles
, and
indu
ces
mus
cle
atro
phy.
Man
y se
cond
ary
impa
irmen
ts
in th
ose
patie
nts,
suc
h as
pre
ssur
e so
res,
low
impa
ct fr
actu
res,
and
dee
p ve
in th
rom
bosi
s ar
e th
ough
t to
be a
t lea
st
parti
ally
rela
ted
to m
uscl
e at
roph
y. Fu
nctio
nal e
lect
rical
stim
ulat
ion
(FES
) has
bee
n us
ed fo
r neu
rore
habi
litat
ion
of
indi
vidu
als
with
suc
h ne
urol
ogic
al d
isor
ders
. FES
has
bee
n us
ed a
s an
ass
istiv
e te
chno
logy
to h
elp
patie
nts
carry
ou
t tas
ks in
dai
ly li
fe, a
s a
ther
apeu
tic to
ol h
elpi
ng m
otor
rele
arni
ng k
now
n as
FES
ther
apy,
and
as a
tool
for m
uscl
e tra
inin
g kn
own
also
as
elec
trica
l mus
cula
r st
imul
atio
n. H
owev
er, o
ne c
omm
on a
spec
t tha
t lim
its it
s us
age
is th
e ra
pid
onse
t of m
uscl
e fa
tigue
, whi
ch s
ever
ely
rest
ricts
the
dura
tion
FES
can
be u
sed.
It is
bel
ieve
d th
at th
e re
vers
e re
crui
tmen
t of m
otor
uni
ts d
urin
g el
ectri
cal s
timul
atio
n is
the
mai
n ca
use
of ra
pid
fatig
ue. A
noth
er re
ason
is th
at a
lo
caliz
ed e
lect
ric f
ield
rep
eate
dly
exci
tes
only
som
e ne
rve
bund
les
that
are
inne
rvat
ing
mus
cles
of
inte
rest
(i.e
., m
uscl
es to
be
stim
ulat
ed).
It
is h
ypot
hesi
zed
that
the
seco
nd re
ason
, loc
aliz
ed e
lect
ric fi
eld,
can
be
addr
esse
d by
stim
ulat
ing
a w
ider
are
a of
the
nerv
e bu
ndle
, whi
ch a
ctiv
ates
mor
e m
otor
uni
ts. T
his
can
be r
ealiz
ed b
y us
ing
mul
tiple
stim
ulat
ion
site
s to
de
liver
ele
ctric
al s
timul
atio
n. I
ndee
d, s
tudi
es h
ave
show
n th
e ef
fect
iven
ess
of s
eque
ntia
l ac
tivat
ion
of m
ultip
le
porti
ons
of n
erve
s in
redu
cing
fatig
ue u
sing
mul
tiple
ele
ctro
des
[1, 2
, 3, 4
]. H
owev
er, a
ll of
thes
e st
udie
s in
vest
igat
ed
stim
ulat
ion
that
req
uire
d in
vasi
ve i
mpl
antin
g of
mul
tiple
ele
ctro
des,
whi
ch i
s no
t su
itabl
e fo
r cl
inic
al u
se.
The
purp
ose
of th
is s
tudy
is to
inve
stig
ate
the
feas
ibilit
y of
redu
cing
mus
cle
fatig
ue b
y di
strib
utin
g th
e el
ectri
c fie
ld o
ver a
w
ider
are
a us
ing
mul
tiple
sur
face
ele
ctro
des
plac
ed o
ver t
he m
uscl
e. If
suc
cess
ful,
such
a te
chni
que
wou
ld a
llow
lo
nger
FES
ses
sion
s du
e to
redu
ced
mus
cle
fatig
ue, l
eadi
ng to
bet
ter r
ehab
ilitat
ion
outc
omes
.
The
view
s exp
ress
ed in
ths p
oste
r do
not n
eces
saril
y re
flect
thos
e of
any
of t
he g
rant
ing
agen
cies
.
The
auth
ors a
ckno
wle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he P
rovi
ncia
l Reh
abili
tatio
n R
esea
rch
Prog
ram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io.
Spat
ially
Dis
trib
uted
Seq
uent
ial S
timul
atio
n (S
DSS
)&
Sin
gle
Elec
trod
e St
imul
atio
n (S
ES)
1C
ompa
rison
bet
wee
n SD
SS a
nd S
ES2
- FES
stim
ulat
es th
e m
otor
ner
ve b
undl
e th
at is
co
nnec
ted
mus
cle
fiber
s at
the
neur
omus
cula
r ju
nctio
n.- W
ith a
regu
lar e
lect
rode
set
up (S
ES),
FES
stim
ulat
es a
lim
ited
area
of t
he m
otor
ner
ve,
resu
lting
in a
ctiv
atin
g a
limite
d m
uscl
e fib
ers.
- With
SD
SS, b
y ch
angi
ng th
e so
urce
of t
he
elec
trica
l fie
ld, F
ES s
timul
ates
a la
rger
are
a of
th
e m
otor
ner
ve, r
esul
ting
in a
ctiv
atin
g m
ore
mus
cle
fiber
s, a
ltern
atel
y.
Ref
eren
ces
[1] L
au H
K, e
t al.
Clin
Orth
op R
elat
Res
251
-258
, 199
5.[2
] Pet
rofs
ky J
. Med
ical
and
Bio
logi
cal E
ngin
eerin
g an
d C
ompu
ting
16:
302-
-308
, 197
8.[3
] Pet
rofs
ky J
. Med
ical
& B
iolo
gica
l Eng
inee
ring
& C
ompu
ting
17: 8
7-93
, 197
9.[4
] Zon
nevi
jlle E
D, e
t al.
Plas
t Rec
onst
r Sur
g 10
5: 6
67-6
73, 2
000.
Brai
n
Spin
al C
ord
Mot
or N
erve
Stim
ulat
ion
Elec
trode
Neu
rom
uscu
lar
Junc
tion
FES
Dev
ice
SES
SDSS
Ner
ve
Mus
cle
SES
SDSS
Elec
trode
Arra
ngem
ents
SES
SDSS 1
２
３４
Tim
e [m
s]0
2550
7510
012
515
017
5
SES
SDSS
1 2 3 4Phas
e Sh
ift o
f Stim
ulat
ion
40 H
z
10 H
z
10 H
z
10 H
z
10 H
z
02468101214
020
4060
8010
012
0
Ankle Torque [Nm]
Tim
e [s
]
SDSS
02468101214
020
4060
8010
012
0
Ankle Torque [Nm]
Tim
e [s
]
SES
00.511.5
SES
SDSS
0
1000
2000
3000
SES
SDSS
FI
TTI [Nms]
p <
0.00
1p
< 0.
0001
030
6090
120
0246810 Ankle torque [Nm]
Tim
e [s
]
SDSS
SES
Expe
rimen
t 1
- For
bot
h m
odes
, the
max
imum
torq
ues
quic
kly
deve
lope
d af
ter o
nset
of s
timul
atio
n an
d fa
tigue
ens
ured
imm
edia
tely
afte
r tha
t. H
owev
er, S
DSS
re
sulte
d in
cle
arly
less
fatig
ue th
an S
ES a
s ev
iden
ced
by a
low
er ra
te o
f tor
que
decl
ine
durin
g th
e fir
st q
uate
r of s
timul
atio
n an
d a
high
er to
rque
pr
oduc
ed a
t the
end
of s
timul
atio
n.- A
ll m
easu
res
of F
I, FT
, and
TTI
qua
ntita
teve
ly a
nd s
tatis
tical
ly s
uppo
rts th
e ab
ovem
entio
ned
obse
rvat
ion,
i.e.
, SD
SS le
ss fa
tigue
.
Expe
rimen
t 2
SES
SDSS
0.00
0.25
0.50
0.75
1.00
FI
SES
SDSS
015304560 FT [s]
SES
SDSS
0
240
480
720
960
TTI [Nm·s]
- In
SES,
a s
et o
f 9 c
m -
5 cm
ele
ctro
des
was
us
ed fo
r the
act
ive
elec
trode
and
the
refe
renc
e el
ectro
de.
- In
SDSS
, an
arra
y el
ectro
de o
f fou
r 4.5
cm
- 2.
5 cm
ele
ctro
des
was
use
d fo
r the
act
ive
elec
trode
, an
d a
9 cm
- 5
cm e
lect
rode
was
for t
he re
fere
nce
elec
trode
.- E
ach
elec
trode
in th
e ar
ray
elec
trode
was
st
imul
ated
with
10
Hz,
with
90
deg
phas
e sh
ift
amon
g th
e ar
ray
elec
trode
s.
Expe
rimen
t 2Su
bjec
ts:
- You
ng h
ealth
y su
bjec
ts: n
= 1
3 (fe
mal
e 5)
, Age
25.
7±7.
0 yr
s, W
eigh
t 64.
8±6.
9 kg
, Hei
ght 1
69±7
cm
Task
: - I
som
etric
, rep
etet
ive
plan
tar f
lexi
on in
a s
ittin
g po
stur
e fo
r 2 m
in, 3
00 m
s-on
and
700
ms-
off
- Com
paris
on b
etw
een
SES
and
SDSS
(see
righ
t col
umn)
- 1 tr
ial f
or e
ach
cond
ition
per
sub
ject
, 2 tr
ials
in s
epar
ated
day
s- F
ES: P
ulse
freq
uenc
y, 40
Hz;
Pul
se w
idth
, 250
us;
Pul
se in
tens
ity, 4
2±6
mA
(SES
) and
39±
6 m
A (S
DSS
)M
easu
rem
ents
:- P
lant
er fl
exio
n to
rque
Ana
lysi
s:- F
I and
TTI
p <
0.00
1
p <
0.00
1p
< 0.
001
- With
the
able
-bod
ied
indi
vidu
als
and
repe
titiv
e co
ntra
ctio
ns, t
he s
imila
r obs
erva
tion
was
obt
aine
d.- F
or b
oth
mea
sure
s of
FI a
nd T
TI, S
DSS
sho
wed
less
fatig
ue c
ompa
red
to S
ES.
Nove
l Meth
odolo
gy to
Red
uce M
uscle
Fat
igue d
urin
g Fun
ction
al El
ectri
cal S
timul
ation
usin
g Spa
tially
Dist
ribut
ed Se
quen
tial S
timul
ation
Mas
ani K
1) ,
Ngu
yen
R 2
) , Po
povi
c M
R 1
, 3)
Toro
nto
Reh
ab is
a te
achi
ng a
nd re
sear
ch h
ospi
tal f
ully
affi
liate
d w
ith th
e U
nive
rsity
of T
oron
to.
1) L
yndh
urst
Cen
tre, T
oron
to R
ehab
ilita
tion
Inst
itute
, Tor
onto
, CA
NA
DA
2) A
utom
atic
Con
trol L
abor
ator
y, E
TH Z
uric
h, S
WIT
ZER
LAN
D3)
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring,
Uni
vers
ity o
f Tor
onto
, Tor
onto
, CA
NA
DA
FIC
CD
ATTo
ront
o, J
une
5-8,
201
1e-
mai
l : k
.mas
ani@
utor
onto
.ca
Can
adia
n In
stitu
tes
of H
ealth
Res
earc
h In
stitu
ts d
e re
cher
e en
san
té d
u C
anad
a N
atur
al S
cien
ces
and
Engi
neer
ing
Res
earc
h C
ounc
il of
Can
ada
Con
seil
de re
cher
ches
en
scie
nces
nat
urel
les
et e
n gé
nie
du C
anad
a
Min
istr
y of
Hea
lth
and
Long
Ter
m C
are
The
view
s ex
pres
sed
in th
is p
oste
r do
not n
eces
saril
y re
flect
thos
e of
any
of t
he g
rant
ing
agen
cies
.
Part
ners
: R
ehab
ilita
tion
Eng
inee
ring
Lab
orat
ory
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
To
ront
o R
ehab
ilita
tion
Inst
itute
C
onta
ct: m
ilos.p
opov
ic@
utor
onto
.ca
ww
w.to
ront
o-fe
s.ca
Puls
e ri
se ti
me
(t ris
e): is
the
time
it ta
kes f
or a
pul
se to
reac
h th
e de
sire
d in
tens
ity. M
inim
izin
g t ri
se a
llow
s gen
erat
ion
of a
ctio
n po
tent
ials
with
less
ele
ctric
cha
rge
(red
uced
PI)
. C
urre
nt v
s. vo
ltage
con
trol:
curr
ent r
egul
ated
pul
ses a
re
pref
eren
tially
use
d be
caus
e th
ey p
rovi
de b
ette
r con
trol o
f the
cha
rge
bein
g ap
plie
d w
hen
tissu
e im
peda
nce
chan
ges (
durin
g th
erap
y or
be
twee
n se
ssio
ns),
prov
idin
g m
ore
cons
iste
nt st
imul
atio
n.
Bas
ed o
n th
e ab
ovem
entio
ned
puls
e re
quire
men
ts, p
ast F
ES
solu
tions
, and
the
need
s of F
ES p
ract
ition
ers a
nd re
sear
cher
s, th
e sp
ecifi
catio
ns o
f the
new
syst
em w
ere
esta
blis
hed
in T
able
1.
i (A)
t (s)
A1
A2PI 4·PI
PD4·
PD
A1=
A2A1
=A2
A1
A2
PI
PI
f puls
ePD
PD
A M
ULT
I-C
HA
NN
EL
CU
RR
EN
T-R
EG
UL
ATE
D O
UT
PUT
STA
GE
FO
R A
N E
LE
CT
RIC
AL
STIM
UL
ATO
R
M. T
arul
li1,3 ,
S. H
uert
a1,3 ,
A. P
rodi
c1 , P.
W. L
ehn1 a
nd M
. R. P
opov
ic2,
3 1.
Dep
artm
ent o
f Ele
ctri
cal a
nd C
ompu
ter
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
, Can
ada
2. In
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eeri
ng, U
nive
rsity
of T
oron
to, C
anad
a 3.
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
y, T
oron
to R
ehab
ilita
tion
Inst
itute
, Can
ada
Elec
trica
l stim
ulat
ion
(ES)
ther
apy
deliv
ers c
harg
e pu
lses
to
exci
tabl
e tis
sue
to im
prov
e, m
odul
ate
or re
stor
e lo
st o
r da
mag
ed n
euro
nal a
nd/o
r mus
cula
r fun
ctio
n. S
peci
fic E
S sy
stem
s tha
t hav
e be
en d
evel
oped
for d
iffer
ent a
pplic
atio
ns
are
limite
d fo
r tw
o m
ain
reas
ons:
1. T
hey
ofte
n do
not
pro
vide
con
sist
ent c
harg
e de
liver
y ov
er th
e fu
ll ra
nge
of ti
ssue
impe
danc
es.
2. T
hey
cann
ot b
e ea
sily
app
lied
to d
iffer
ent a
reas
of t
he
body
with
out m
ajor
adj
ustm
ent o
r red
esig
n.
This
pap
er e
luci
date
s a n
ovel
ele
ctric
al st
imul
ator
pla
tform
th
at so
lves
the
prob
lem
s abo
ve b
y:
1. A
chie
ving
the
sam
e m
uscl
e co
ntra
ctio
n as
stat
e of
the
art s
olut
ions
with
sign
ifica
ntly
low
er c
harg
e us
ing
shar
per,
bette
r con
trolle
d pu
lses
. 2. E
mpl
oyin
g a
flexi
ble
digi
tal p
latfo
rm to
acc
omm
odat
e vi
rtual
ly a
ll FE
S ap
plic
atio
ns.
Bac
kgro
und
and
Mot
ivat
ion
Fig1
– K
ey p
ulse
cha
ract
eris
tics.
1. F
irst
stag
e: th
e ba
ttery
(inp
ut) v
olta
ge is
step
ped
up to
seve
ral
hund
red
volts
with
bui
lt in
isol
atio
n fr
om th
e pa
tient
. 2. S
econ
d pu
lse
shap
ing
circ
uitr
y st
age:
cre
ates
the
desi
red
stim
ulat
ion
puls
es w
ith ti
ght a
nd fa
st re
gula
tion
of c
urre
nt
ampl
itude
leve
l.
This
nov
el se
tup
has m
any
adva
ntag
es:
1.
Bui
lt in
cha
rge
bala
ncin
g en
sure
s no
exce
ss c
harg
e is
pre
sent
in
the
tissu
e of
the
patie
nt fo
llow
ing
a si
ngle
pul
se d
eliv
ery.
2.
A d
igita
l con
trolle
r for
dyn
amic
cur
rent
regu
latio
n, p
rovi
ding
ex
quis
ite p
ulse
shap
es a
nd in
here
nt c
urre
nt o
verlo
ad p
rote
ctio
n.
3.
A p
rogr
amm
able
dig
ital p
latfo
rm th
at g
ener
ates
man
y di
ffere
nt
type
s of p
ulse
s, va
ryin
g in
dur
atio
n, a
mpl
itude
and
freq
uenc
y.
4.
The
abili
ty fo
r clo
sed
loop
func
tiona
lity
usin
g in
puts
from
va
rious
sens
ory
mod
aliti
es.
In d
evel
opin
g th
e ne
w fl
exib
le o
utpu
t sta
ge, s
ever
al k
ey
stim
ulat
ion
char
acte
ristic
s had
to b
e bo
th ti
ghtly
con
trolle
d an
d re
adily
adj
usta
ble:
Pu
lse
shap
e: F
ig1
show
s bip
hasi
c as
ymm
etric
(lef
t) an
d bi
phas
ic sy
mm
etric
pul
ses (
right
). Fo
r bal
ance
d pu
lses
, the
ch
arge
del
iver
ed a
nd re
mov
ed m
ust b
e m
aint
aine
d ov
er ti
me,
to
avo
id d
amag
ing
char
ge re
tent
ion
in ti
ssue
. Pu
lse
dura
tion
(PD
): sh
ould
be
long
eno
ugh
so th
e la
tent
pe
riod,
act
ion
pote
ntia
l and
reco
very
take
pla
ce. T
he la
rger
th
e m
uscl
e gr
oups
, the
gre
ater
PD
nee
ded(
up to
seve
ral m
s).
Puls
e fre
quen
cy (f
puls
e): sh
ould
gen
erat
e co
ntin
uous
mus
cle
(teta
nic)
con
tract
ions
(>40
Hz)
and
dis
cont
inuo
us m
uscl
e (n
on-te
tani
c) c
ontra
ctio
n (b
etw
een
16 H
z an
d 40
Hz)
. Pu
lse
inte
nsity
(PI)
: sho
uld
be h
igh
enou
gh to
pro
duce
an
actio
n po
tent
ial.
The
deep
er a
nd/o
r lar
ger m
uscl
es, t
he
grea
ter t
he P
I nee
ded
(up
to o
ver 1
00m
A).
Stim
ulat
ion
Puls
es a
nd S
peci
ficat
ions
Feature
Specification
Varia
ble
puls
e in
tens
ity
0.5m
A –
125
mA
(res
olut
ion
0.5m
A)
Varia
ble
puls
e fr
eque
ncy
1Hz
– 15
kHz,
(res
olut
ion
of 1
Hz)
Va
riabl
e pu
lse
dura
tion
10µs
– 1
0ms (
reso
lutio
n of
1µs
) U
ltraf
ast p
ulse
rise
tim
e 10
ns
Varia
ble
puls
e sh
ape
Bip
hasi
c (S
ymm
etric
/Asy
mm
etric
) M
onop
hasi
c (P
ositi
ve/N
egat
ive)
B
alan
ced
puls
es
No
resi
dual
cha
rge
left
in ti
ssue
Vo
ltage
and
cur
rent
pr
otec
tion
Imm
edia
te sh
utdo
wn
if vo
ltage
or
curr
ent e
xcee
ds a
llow
able
lim
it M
ultip
le st
imul
atio
n ch
anne
ls
4 in
depe
nden
tly re
gula
ted
stim
ulat
ion
chan
nels
Tabl
e 1
– N
ew st
imul
ator
spec
ifica
tions
Figs
2 a
and
b sh
ow e
xam
ples
of p
ulse
s gen
erat
ed w
ith th
e ne
w
outp
ut st
age
of th
e st
imul
ator
. Fig
3 hi
ghlig
hts t
he u
ltraf
ast r
ise
time.
Th
e ne
w st
imul
ator
has
seve
ral i
mpr
ovem
ents
ove
r cur
rent
syst
em:
• Tw
o or
ders
of m
agni
tude
fast
er ri
se ti
me,
redu
cing
am
plitu
de
• Ti
ghte
r and
safe
r reg
ulat
ion
of c
urre
nt d
eliv
ered
to th
e pa
tient
•
Bro
ad p
erfo
rman
ce e
nvel
ope
enco
mpa
ssin
g al
l ES
appl
icat
ions
. R
esul
ts a
nd C
oncl
usio
n t rise
= 1
0 ns -10
mA
, -22
V
0 m
A, 0
V
Fig2
a –
Ass
ymet
ric
Bip
hasi
c Pu
lse
Fig3
– U
ltraf
ast r
ise
time
The
four
-cha
nnel
stim
ulat
or c
onsi
sts o
f tw
o st
ages
of s
witc
hed
mod
e po
wer
supp
lies a
rran
ged
in se
ries.
Thes
e su
pplie
s ser
ve tw
o im
porta
nt fu
nctio
ns:
Met
hods
i load
1 m
s
0 A
12.5
mA
-50
mA
R l
oad ≈
1 kΩ
250 µs
-50
mA
50 m
A
i load
R loa
d ≈
1 kΩ
250 µs
250 µs
Fig2
b –
Sym
etri
c B
ipha
sic
Puls
e
Canadian Institutes of Health Research Instituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of Canada Conseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health and Long Term Care
Partners: Rehabilitation Engineering Laboratory Institute of Biomaterials and Biomedical Engineering, University of Toronto Toronto Rehabilitation Institute Contact: [email protected] www.toronto-fes.ca
INCLUDING NON-IDEAL BEHAVIOUR IN FES SIMULATIONS C.L. Lynch1,2, G.M. Graham, and M.R. Popovic1,2
( ) ( ) ( ) ( )( ) ( )tfattmtstt ⋅++= τν
• Functional electrical stimulation (FES) can be used to restore or replace motor function in individuals with spinal cord injuries (SCI). • New SCI applications must be thoroughly tested with SCI subjects – time-consuming and expensive, so simulations are used to refine design of FES applications prior to testing with subjects. • FES simulations are often based on ideal stimulated muscle response, which may result in an overly optimistic assessment of FES system’s likely real-world performance. • We created a “non-idealities” block in Simulink with data from complete SCI subjects.
• Modifies nominal stimulated muscle response to reflect undesirable behaviour seen in real world. • Represents the range of spasm, tremor, and fatigue behaviour exhibited by stimulated muscles. • Can be incorporated into existing simulations to analyze potential real-world performance of FES systems.
Introduction
References [1] Graham GM, Thrasher TA, Popovic MR. IEEE Trans Neural Syst Rehabil Eng, 14:38-45, 2006. [2] Ferrarin M, Pedotti A. IEEE Trans Rehabil Eng, 8:342-352, 2000.
1. IBBME, University of Toronto, Toronto, Canada 2. Rehabilitation Engineering Laboratory, Toronto Rehab, Toronto, Canada
• Modified torque produced by non-idealities block differs from nominal torque. • Fatigue, tremors had a large effect on control performance. • Real-world control performance may be modestly better than simulated results due to unmodeled muscle recovery. • Isotonic contractions in trained muscles may have different fatigue profiles than those used in non-idealities block. • Non-idealities block does not reflect all possible undesirable behaviour that can occur with real-world FES use.
Discussion
• Fig 2 shows effect of non-idealities block. Dotted line is nominal knee torque at maximum stimulation. Solid line is modified torque for mild spasms, fatigue, and tremor. • Fig 3 shows unit step tracking performance for PID controller. Dotted line is without non-idealities block, and solid line is with block (mild spasms, fatigue, and tremor).
Results
• Spasm, tremor, and fatigue waveforms were extracted from stimulated knee movements of complete SCI subjects.
• Fatigue waveforms were scaled between 0 and 1 [1]. • Each non-ideality waveform was classified as mild, moderate, or severe.
• Non-idealities block is implemented in Simulink, and allows user to choose severity of non-idealities included in particular instance of block.
• Actual waveform that is used for each non-ideality is chosen randomly from group of waveforms having desired classification.
• Eqn 1 gives output of block, where \tau(t) is nominal stimulated muscle torque, \nu(t) is modified torque, and s(t), m(t), and fat(t) are instances of spasm, tremor, and fatigue waveforms. • Fig 1 shows example of implementation of non-idealities block in FES simulation.
• PID controller is used to track desired knee angle. • Based on Ferrarin & Pedotti’s model of seated, stimulated knee extension against gravity [2].
Methods
• Non-idealities block allows researchers to assess likely real-world performance of FES systems prior to subject testing. • MatLab code for block will be freely available on our website (targeted release date – early 2011).
Conclusions PID
Controller
StimulatedQuadricepsResponse
Knee Dynamics
Non-Idealities
BlockΣ
θREF
θ
e u τ θυ_+
Fig 1 – Diagram of knee control simulation (θ is knee angle)
Fig 2 – Nominal torque at maximum stimulation, and modified torque from non-idealities block (mild spasms, fatigue, and tremor)
Fig 3 – Sample implementation – unit step tracking with PID control (dotted line is nominal case, solid line is with non-idealities block).
Equation 1 – Output of non-idealities block
Canadian Institutes of Health Research Instituts de rechere en santé du Canada
Natural Sciences and Engineering Research Council of Canada Conseil de recherches en sciences naturelles et en génie du Canada
Ministry of Health and Long Term Care
Partners: Rehabilitation Engineering Laboratory Institute of Biomaterials and Biomedical Engineering, University of Toronto Toronto Rehabilitation Institute Contact: [email protected] www.toronto-fes.ca
INCLUDING NON-IDEAL BEHAVIOUR IN SIMULATIONS OF FES C.L. Lynch1,2, G.M. Graham2, and M.R. Popovic1,2
• Functional electrical stimulation (FES) can be used to restore or replace motor function in individuals with spinal cord injuries (SCI). • New SCI applications must be thoroughly tested with SCI subjects – time-consuming and expensive, so simulations are used to refine design of FES applications prior to testing. • FES simulations are often based on ideal stimulated muscle response, which may result in an overly optimistic assessment of FES system’s likely real-world performance. • We created a “non-idealities” block in Simulink with data from complete SCI subjects (injury levels C6 through T10).
• Block modifies nominal stimulated muscle response to reflect undesirable behaviour seen in real world. • Represents the range of spasm, tremor, and fatigue behaviour exhibited by stimulated muscles. • Can be incorporated into existing simulations to analyze potential real-world performance of FES systems.
Introduction
References [1] Graham GM, Thrasher TA, Popovic MR. IEEE Trans Neural Syst Rehabil Eng, 14:38-45, 2006. [2] Ferrarin M, Pedotti A. IEEE Trans Rehabil Eng, 8:342-352, 2000.
1. IBBME, University of Toronto, Toronto, Canada 2. Rehabilitation Engineering Laboratory, Toronto Rehab, Toronto, Canada
• Performance of SMC is good for nominal case and poor for cases that include non-idealities, as shown in Figs 2 and 3. • Inclusion of non-idealities block shows that controller is not ready for testing with human subjects. • Spasticity improved controller performance, possibly due to increased damping of the knee joint. • Real-world control performance may be modestly better than simulated results due to unmodeled muscle recovery. • Isotonic contractions in trained muscles may have different fatigue profiles than those used in non-idealities block.
Discussion
• Fig 2 shows the step response for the nominal case and the case with mild fatigue, mild spasms, and mild tremors. • Fig 3 shows the response for a walking-like trajectory for the same cases shown in Fig 2.
Results
• Spasm, tremor, and fatigue waveforms were extracted from stimulated knee movements of complete SCI subjects.
• Fatigue waveforms were scaled between 0 and 1 [1]. • Each non-ideality waveform was classified as mild, moderate, or severe.
• Non-idealities block was implemented in Simulink, and allows user to choose severity of non-idealities included in particular instance of block.
• Actual waveform that is used for each non-ideality is chosen randomly from group of waveforms having desired class.
• Eqn 1 gives output of block, where is nominal stimulated muscle torque, is modified torque, and s(t), m(t), and fat(t) are instances of spasm, tremor, and fatigue waveforms • Fig 1 shows implementation of non-idealities block in simulation.
• Boundary-layer sliding mode controller (SMC) is used to track desired knee angle. • Based on Ferrarin & Pedotti’s model of seated, stimulated knee extension against gravity [2].
Methods
• Non-idealities block illustrates that real-world performance of controller may be vastly different from nominal performance. • Non-idealities block provides a convenient method of comprehensively testing FES systems in simulation. • MatLab code for block will be freely available in early 2011 at www.toronto-fes.ca under Products.
Conclusions
Sliding Mode Controller
StimulatedQuadricepsResponse
Knee Dynamics
Non-Idealities
BlockΣ
θREF
θ
e u τ θυ_+
Fig 1 – Diagram of knee control simulation (θ is knee angle)
Fig 2 – Step response. Thin line is reference trajectory, dashed line is response for nominal knee model, and thick solid line is response for model with mild non-idealities included.
Fig 3 – Response for walking-like trajectory. Thin line is reference trajectory, dashed line is response for nominal knee model, and thick solid line is response for model with mild non-idealities.
( ) ( ) ( ) ( )( ) ( )tfattmtstt quad ⋅++= τν
Equation 1 – Output of non-idealities block
)(tquadτ)(tν
PURP
OSE
PURP
OSE
CO
NC
LUSI
ON
CO
NC
LUSI
ON
To e
xplo
re t
he f
atig
ue-re
duci
ng a
bilit
y of
spa
tially
dis
tribu
ted
sequ
entia
l stim
ulat
ion
(SD
SS) f
or m
ajor
low
er li
mb
mus
cle
grou
ps
- The
effe
ctiv
enes
s of
usi
ng S
DSS
to r
educ
e m
uscl
e fa
tigue
was
sho
wn
in o
ne in
divi
dual
with
SC
I for
pla
ntar
flexo
rs a
nd a
ble-
bodi
ed in
divi
dual
s fo
r kne
e ex
tens
ors/
flex
ors
and
plan
tarfl
exor
s .
- The
resu
lts w
arra
nt th
e po
tent
ial o
f SD
SS to
pro
long
trai
ning
ses
sion
s of
var
ious
FES
ther
apy.
Partn
ers:
Reh
abili
tatio
n E
ngin
eeri
ng L
abor
ator
y,
Inst
itute
of B
iom
ater
ials
and
Bio
med
ical
Eng
inee
ring
, Uni
vers
ity o
f Tor
onto
Toro
nto
Reh
abili
tatio
n In
stitu
teC
onta
ct: k
.mas
ani@
utor
onto
.ca
web
pag
e: h
ttp:
//ww
w.to
ront
o-fe
s.ca
Subj
ects
: - A
n in
divi
dual
with
com
plet
e SC
I, T3
/T4,
ASI
A A,
4 y
ears
pos
t inj
ury
Task
: - I
som
etric
, con
tinuo
us p
lant
ar fl
exio
n in
a s
ittin
g po
stur
e fo
r 2 m
in- C
ompa
rison
bet
wee
n SE
S an
d SD
SS (s
ee th
e rig
ht c
olum
n)- 1
2 tri
als
in s
epar
ated
day
s (6
SES
and
6 S
DSS
)- F
ES: P
ulse
freq
uenc
y, 40
Hz;
Pul
se w
idth
, 250
us;
Pul
se in
tens
ity, 6
4±5
mA
(SES
) and
51±
4 m
A (S
DSS
)M
easu
rem
ents
:- P
lant
er fl
exio
n to
rque
Ana
lysi
s:- F
atig
ue In
dex
(FI):
Tor
que
at th
e en
d of
the
2 m
in s
timul
atio
n no
rmal
ized
to th
e m
axim
um
torq
ue- F
atig
ue T
ime
(FT)
: Diff
eren
ce in
tim
e fro
m w
hen
the
max
imum
torq
ue w
as a
chie
ved
to
whe
n th
e th
e to
rque
dro
pped
by
3 dB
- Tor
que-
Tim
e In
tegr
al (T
TI):
Inte
gral
of t
orqu
e ov
er th
e en
tire
2 m
in fa
tigui
ng s
timul
atio
n
Expe
rimen
t 1 [1
3]
BA
CK
GR
OU
ND
BA
CK
GR
OU
ND
Neu
rom
uscu
lar
elec
trica
l st
imul
atio
n (N
MES
) is
use
d to
pro
mot
e ph
ysio
logi
cal
and
func
tiona
l im
prov
emen
t in
pa
raly
sed
limbs
[1, 2
] and
cou
nter
act m
uscu
losk
elet
al a
troph
y [3
, 4].
How
ever
, whi
le it
has
suc
ceed
ed in
ass
istin
g in
divi
dual
s w
ith n
euro
mus
cula
r di
sord
ers,
a c
ritic
al li
mita
tion
with
this
reh
abilit
ativ
e ap
proa
ch is
the
rapi
d on
set o
f m
uscl
e fa
tigue
dur
ing
repe
ated
con
tract
ions
[5],
whi
ch r
esul
ts in
the
mus
cle
forc
e de
cay
and
slow
ing
of m
uscl
e co
ntra
ctile
pro
perti
es [6
].Th
e in
crea
sed
fatig
abilit
y w
ith N
MES
is th
ough
t by
som
e re
sear
cher
s to
ref
lect
a r
ever
sal o
f the
siz
e pr
inci
ple
of
recr
uitm
ent
[7],
whe
n la
rger
axo
ns t
hat
inne
rvat
e th
e m
ore
easi
ly f
atig
able
fib
ers
are
recr
uite
d at
low
stim
ulus
m
agni
tude
s, a
nd th
e sm
alle
r axo
ns fo
llow
with
incr
ease
d st
imul
atio
n le
vels
[1, 5
]. An
othe
r pla
usib
le e
xpla
natio
n is
th
at, w
hile
dur
ing
volu
ntar
y co
ntra
ctio
n, th
e w
ork
is b
eing
sha
red
betw
een
diffe
rent
mot
or u
nits
of t
he s
ame
mus
cle
[5],
conv
entio
nal N
MES
doe
s no
t per
mit
alte
ratio
ns in
rec
ruitm
ent o
f mot
or u
nits
bec
ause
all
para
met
ers
rem
ain
fixed
dur
ing
the
bout
[5].
One
of t
he m
eans
to c
ount
er fo
rce
loss
dur
ing
elec
trica
l stim
ulat
ion
is a
imed
at a
chie
ving
an
asyn
chro
nous
beh
avio
r by
del
iver
ing
elec
trica
l st
imul
atio
n th
roug
h m
ultip
le e
lect
rode
loc
atio
ns o
n a
sing
le s
ite,
prod
ucin
g a
fuse
d co
ntra
ctio
n w
ith re
lativ
ely
low
stim
ulat
ion
rate
s, a
nd d
elay
ing
the
onse
t of f
atig
ue. T
his
type
of s
patia
lly d
istri
bute
d an
d se
quen
tially
app
lied
stim
ulat
ion
is r
efer
red
to a
s 'se
quen
tial
stim
ulat
ion'
. Fa
tigue
was
red
uced
with
suc
h st
imul
atio
n, w
idel
y sh
own
in a
nim
al e
xper
imen
tal m
odel
s [8
-11]
. Unt
il no
w, o
nly
a fe
w s
tudi
es [1
2-14
] inv
estig
ated
th
is s
timul
atio
n m
etho
d in
hum
an e
xper
imen
tal
setu
ps,
how
ever
, th
is m
etho
d ha
s no
t be
en s
ucce
ssfu
lly
inco
rpor
ated
into
clin
ical
app
licat
ions
.
The
view
s exp
ress
ed in
ths p
oste
r do
not n
eces
saril
y re
flect
thos
e of
any
of t
he g
rant
ing
agen
cies
.
The
auth
ors a
ckno
wle
dge
the
supp
ort o
f Tor
onto
Reh
abili
tatio
n In
stitu
te w
ho re
ceiv
es fu
ndin
g un
der t
he P
rovi
ncia
l Reh
abili
tatio
n R
esea
rch
Prog
ram
from
the
Min
istry
of H
ealth
and
Lon
g-Te
rm C
are
in O
ntar
io.
Spat
ially
Dis
trib
uted
Seq
uent
ial S
timul
atio
n (S
DSS
)&
Sin
gle
Elec
trod
e St
imul
atio
n (S
ES)
1C
ompa
rison
bet
wee
n SD
SS a
nd S
ES2
- FES
stim
ulat
es th
e m
otor
ner
ve b
undl
e th
at is
co
nnec
ted
mus
cle
fiber
s at
the
neur
omus
cula
r ju
nctio
n.- W
ith a
regu
lar e
lect
rode
set
up (S
ES),
FES
stim
ulat
es a
lim
ited
area
of t
he m
otor
ner
ve,
resu
lting
in a
ctiv
atin
g a
limite
d m
uscl
e fib
ers.
- With
SD
SS, b
y ch
angi
ng th
e so
urce
of t
he
elec
trica
l fie
ld, F
ES s
timul
ates
a la
rger
are
a of
th
e m
otor
ner
ve, r
esul
ting
in a
ctiv
atin
g m
ore
mus
cle
fiber
s, a
ltern
atel
y.
Brai
n
Spin
al C
ord
Mot
or N
erve
Stim
ulat
ion
Elec
trode
Neu
rom
uscu
lar
Junc
tion
FES
Dev
ice
SES
SDSS
Mus
cle
SES
SDSS
Elec
trode
Arra
ngem
ents
SES
SDSS 1
２
３４
Tim
e [m
s]0
2550
7510
012
515
017
5
SES
SDSS
1 2 3 4Phas
e Sh
ift o
f Stim
ulat
ion
40 H
z
10 H
z
10 H
z
10 H
z
10 H
z
02468101214
020
4060
8010
012
0
Ankle Torque [Nm]
Tim
e [s
]
SDSS
02468101214
020
4060
8010
012
0
Ankle Torque [Nm]
Tim
e [s
]
SES
030
6090
120
0246810 Ankle torque [Nm]
Tim
e [s
]
SDSS
SES
Expe
rimen
t 1
- For
bot
h m
odes
, the
max
imum
torq
ues
quic
kly
deve
lope
d af
ter o
nset
of s
timul
atio
n an
d fa
tigue
ens
ured
imm
edia
tely
afte
r tha
t. H
owev
er, S
DSS
re
sulte
d in
cle
arly
less
fatig
ue th
an S
ES a
s ev
iden
ced
by a
low
er ra
te o
f tor
que
decl
ine
durin
g th
e fir
st q
uate
r of s
timul
atio
n an
d a
high
er to
rque
pr
oduc
ed a
t the
end
of s
timul
atio
n.- A
ll m
easu
res
of F
I, FT
, and
TTI
qua
ntita
teve
ly a
nd s
tatis
tical
ly s
uppo
rts th
e ab
ovem
entio
ned
obse
rvat
ion,
i.e.
, SD
SS le
ss fa
tigue
.
Expe
rimen
t 2
SES
SDSS
0.00
0.25
0.50
0.75
1.00
FI
SES
SDSS
015304560 FT [s]
SES
SDSS
0
240
480
720
960
TTI [Nm·s]
- In
SES,
a s
et o
f 9 c
m -
5 cm
ele
ctro
des
was
us
ed fo
r the
act
ive
elec
trode
and
the
refe
renc
e el
ectro
de.
- In
SDSS
, an
arra
y el
ectro
de o
f fou
r 4.5
cm
- 2.
5 cm
ele
ctro
des
was
use
d fo
r the
act
ive
elec
trode
, an
d a
9 cm
- 5
cm e
lect
rode
was
for t
he re
fere
nce
elec
trode
.- E
ach
elec
trode
in th
e ar
ray
elec
trode
was
st
imul
ated
with
10
Hz,
with
90
deg
phas
e sh
ift
amon
g th
e ar
ray
elec
trode
s.
Expe
rimen
t 2Su
bjec
ts:
- You
ng h
ealth
y m
ale
subj
ects
: n =
15
Task
: - K
nee
exte
nsio
n, k
nee
flexi
on, p
lant
ar fl
exio
n, a
nd d
orsi
flex
ion
- Iso
met
ric, r
epet
etiv
e co
ntra
ctio
n in
a s
ittin
g po
stur
e fo
r 2 m
in, 3
00 m
s-on
and
700
ms-
off
- Com
paris
on b
etw
een
SES
and
SDSS
(see
righ
t col
umn)
- 4 tr
ials
for e
ach
join
t with
eac
h co
nditi
on p
er s
ubje
ct in
a d
ay, 2
sep
arat
ed d
ays
for 2
con
ditio
ns- F
ES: P
ulse
freq
uenc
y, 40
Hz;
Pul
se w
idth
, 250
us
Mea
sure
men
ts:
- Joi
nt to
rque
Ana
lysi
s:- F
I
p <
0.00
1
p <
0.00
1p
< 0.
001
- With
the
able
-bod
ied
indi
vidu
als
and
repe
titiv
e co
ntra
ctio
ns, t
he s
imila
r obs
erva
tion
was
obt
aine
d.- E
xcep
t for
dor
sifle
xors
, SD
SS s
how
ed s
igni
fican
tly le
ss fa
tigue
com
pare
d to
SES
.
Impr
oved
Fat
igue R
esist
ance
in L
eg M
uscle
s dur
ing S
patia
lly D
istrib
uted
Sequ
entia
l Stim
ulat
ionSa
yenk
o D
G 1
) , Po
povi
c M
R 1
, 2) ,
Mas
ani K
1, 2
)
Toro
nto
Reh
ab is
a te
achi
ng a
nd re
sear
ch h
ospi
tal f
ully
affi
liate
d w
ith th
e U
nive
rsity
of T
oron
to.
1) L
yndh
urst
Cen
tre, T
oron
to R
ehab
ilita
tion
Inst
itute
, Tor
onto
, CA
NA
DA
2) In
stitu
te o
f Bio
mat
eria
ls a
nd B
iom
edic
al E
ngin
eerin
g, U
nive
rsity
of T
oron
to, T
oron
to, C
AN
AD
A
IFES
SB
anff,
Alb
erta
, Can
ada,
Sept
embe
r 9 -
12, 2
012
e-m
ail :
k.m
asan
i@ut
oron
to.c
a
Hyp
othe
size
d M
echa
nism
- In
SES,
a s
mal
ler n
umbe
r of m
uscl
e fib
res
are
activ
ated
con
tinuo
usly
with
a h
igh
frequ
ency
.- I
n SD
SS, a
larg
er n
umbe
r of m
uscl
e fib
res
are
activ
ated
alte
rnat
ivel
y w
ith a
low
freq
uenc
y.00.2
0.4
0.6
0.81
00.2
0.4
0.6
0.81
00.2
0.4
0.6
0.81
00.2
0.4
0.6
0.81
SES
SDSS
SES
SDSS
FI FI
Knee
Ext
Knee
Flx
Plan
tarF
lxD
orsi
Flx
p =
0.03
p =
0.00
7
p =
0.03
p =
0.07
Ref
eren
ces
[1] S
heffl
er L
R, C
hae
J. M
uscl
e N
erve
200
7; 3
5(5)
: 562
-90.
[2] P
eckh
am P
H, K
nuts
on J
S. A
nnu
Rev
Bio
med
Eng
200
5; 7
: 327
-60.
[3] B
ergq
uist
AJ,
et a
l. Eu
r J A
ppl P
hysi
ol 2
011;
111
(10)
: 240
9-26
.[4
] Dud
ley-
Javo
rosk
i S, S
hiel
ds R
K. J
Reh
abil
Res
Dev
200
8; 4
5(2)
: 283
- 96.
[5] B
icke
l CS,
et a
l. Eu
r J A
ppl P
hysi
ol 2
011;
111
(10)
: 239
9-40
7.[6
] Jon
es D
A. J
Phy
siol
201
0; 5
88(P
t 16)
: 297
7-86
.[7
] Hen
nem
an E
, et a
l. J
Neu
roph
ysio
l 196
5; 2
8(3)
: 599
- 620
.[8
] Lau
HK,
et a
l. C
lin O
rthop
Rel
at R
es 1
995;
(321
): 25
1-8.
[9] Z
onne
vijlle
ED
, et a
l. Pl
ast R
econ
str S
urg
2000
; 105
(2):
667-
73.
[10]
Lau
B, e
t al.
IEEE
Tra
ns N
eura
l Sys
t Reh
abil
Eng
2007
; 15(
2): 2
73-8
5.[1
1] Y
oshi
da K
, Hor
ch K
. Ann
Bio
med
Eng
199
3; 2
1(6)
: 709
-14.
[12]
Mal
esev
ic N
M, e
t al.
Mus
cle
Ner
ve 2
010;
42(
4): 5
56-6
2.[1
3] N
guye
n R
, et a
l. Ar
tif O
rgan
s 20
11; 3
5(12
): 11
74-8
0.[1
4] P
opov
ic L
Z, M
ales
evic
NM
. Con
f Pro
c IE
EE E
ng M
ed B
iol S
oc 2
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