NORMATIVE DATA OF THE SENSORY ORGANIZATION TEST, …
Transcript of NORMATIVE DATA OF THE SENSORY ORGANIZATION TEST, …
ABSTRACT
NORMATIVE DATA OF THE SENSORY ORGANIZATION TEST, THE MOTOR CONTROL TEST, AND THE
ADAPTATION TEST ON THE BERTEC BALANCE ADVANTAGE® IN
HEALTHY ADULTS
Objective: The purpose of this study was to determine test-retest reliability
and obtain normative values in healthy adults age 20-69 during computerized
dynamic posturography using the Bertec Balance Advantage®. Bertec values were
compared to published NeuroCom® normative values and across age groups to
determine any differences.
Methods: 50 healthy adults divided into 5 age groups were tested during the
3 test protocols for CDP: Sensory Organization Test (SOT), Motor Control Test
(MCT), and Adaptation Test (ADT). Five different subjects were tested on 2 days,
1 week apart, to determine between day reliability.
Results: Majority of conditions had moderate to good reliability on the
Bertec® (r = .55-.99). Differences between age groups occurred on SOT condition
2 and somatosensory ratio score and ADT toes down. When compared to
NeuroCom®, largest differences occurred on condition 4 of SOT and ADT test.
Conclusion: Bertec Balance Advantage® may be used to test whether or not
a person’s balance is impaired. MCT and SOT composite and equilibrium scores
for conditions 3-6 were comparable to the NeuroCom® normative values.
Keywords: Bertec Balance Advantage®, Sensory Organization Test, Motor
Control Test, Adaptation Test, Computerized Dynamic Posturography
Christian Lopez May 2017
NORMATIVE DATA OF THE SENSORY ORGANIZATION
TEST, THE MOTOR CONTROL TEST, AND THE
ADAPTATION TEST ON THE BERTEC
BALANCE ADVANTAGE® IN
HEALTHY ADULTS
by
Christian Lopez
A project
submitted in partial
fulfillment of the requirements for the degree of
Doctor of Physical Therapy
in the Department of Physical Therapy
College of Health and Human Services
California State University, Fresno
May 2017
APPROVED
For the Department of Physical Therapy:
We, the undersigned, certify that the project of the following student meets the required standards of scholarship, format, and style of the university and the student's graduate degree program for the awarding of the doctoral degree. Christian Lopez
Project Author
Peggy Trueblood (Chair) Physical Therapy
Monica Rivera Physical Therapy
Nancy Wubenhorst Physical Therapy
For the University Graduate Committee:
Dean, Division of Graduate Studies
AUTHORIZATION FOR REPRODUCTION
OF DOCTORAL PROJECT
X I grant permission for the reproduction of this project in part or in
its entirety without further authorization from me, on the
condition that the person or agency requesting reproduction
absorbs the cost and provides proper acknowledgment of
authorship.
Permission to reproduce this project in part or in its entirety must
be obtained from me.
Signature of project author:
ACKNOWLEDGMENTS
I would like to thank my committee members Dr. Peggy Trueblood, Dr.
Monica Rivera, and Nancy Wubenhorst for all of their help and support through
out the development of this research project. This could not have been
accomplished without their guidance. I want to give a special thanks to my friends
and family who have always believed in me. I would like to thank the entire
Fresno State Physical Therapy Department for accepting me into the program and
providing me the opportunity to become a physical therapist. And most of all, I
would like to thank my 29 classmates who have been on this journey with me
every step of the way.
TABLE OF CONTENTS
Page
LIST OF TABLES .................................................................................................. vi
LIST OF FIGURES ................................................................................................ vii
BACKGROUND ...................................................................................................... 1
METHODS ............................................................................................................... 6
Pilot Study ......................................................................................................... 6
Normative Study ............................................................................................... 6
Data Analysis .................................................................................................. 10
RESULTS ............................................................................................................... 11
Reliability Pilot Study ..................................................................................... 11
Subjects ........................................................................................................... 11
Comparison Between Age Groups .................................................................. 12
Comparison to NeuroCom® Normative Values .............................................. 13
DISCUSSION ......................................................................................................... 14
Limitations ...................................................................................................... 17
Conclusion ....................................................................................................... 18
REFERENCES ....................................................................................................... 20
TABLES ................................................................................................................. 26
FIGURES ............................................................................................................... 30
APPENDICES ........................................................................................................ 34
APPENDIX A: STUDY IRB ................................................................................. 35
APPENDIX B: HEALTH QUESTIONNAIRE ..................................................... 42
LIST OF TABLES
Page
Table 1. Reliability Values of the SOT from Initial Pilot Study ............................ 27
Table 2. Reliability Values of MCT and ADT from Pilot Study ........................... 28
Table 3. Reliability Categories of Initial Pilot Study for All Conditions ............... 28
Table 4 Means ± SD for SOT Equilibrium and Ratio Scores, MCT Latencies, and ADT Averaged Sway Energy Scores for All Age Groups ................ 29
LIST OF FIGURES
Page
Figure 1. Sensory organization test condition 2 means and standard deviations comparing age groups ............................................................................. 31
Figure 2. Somatosensory equilibrium scores given in means and standard deviations comparing age groups ........................................................... 31
Figure 3. SOT Bertec® means compared to NeuroCom® norms7 .......................... 32
Figure 4. MCT Bertec® means and standard deviations compared to NeuroCom® norms7 ................................................................................. 32
Figure 5. Comparison of toes up means and standard deviations of sway energy scores on Bertec® compared to NeuroCom® norms7 .................. 33
Figure 6. Comparison of toes down means and standard deviations of sway energy scores on Bertec® compared to NeuroCom® norms7 .................. 33
BACKGROUND
Balance is a critical, yet underappreciated and complex part of everyday
life. It can be defined as the ability to control upright posture under different
conditions, and the ability of an individual to sense their limitations of stability.1
Deficits in balance is a risk factor for falls and can lead to serious injury such as
hip fractures, hospitalization, and even death.2 Falls are also responsible for a
significant amount of health care spending, as they account for over $31 billion in
direct medical cost annually.3 Various methods have been introduced in order to
measure balance, however, tests commonly used in the clinic are not always
consistent due to their variable execution and subjective scoring systems.4,5
Therefore, there is a need to have procedures and protocols that can help
determine fall risk, as well as monitor improvements through rehabilitation.
In the 1980s, computerized dynamic posturography (CDP) devices were
developed. These devices are capable of measuring the ability of a person to shift
their center of pressure (CoP) within their base of support (BoS) and towards the
perimeter under various manipulations of the environment, which is known as
dynamic balance.6 It was during this time that Nashner and associates developed
the NeuroCom EquiTest®, which is capable of measuring and quantifying how a
person utilizes various sensory information in order to remain balanced under
different conditions. The CDP is composed of 3 test protocols, the sensory
organization test (SOT), the motor control test (MCT), and the adaptation test
(ADT).7 Computerized dynamic posturography has been used to measure and
monitor progress in patients who are undergoing balance rehabilitation, evaluate
balance after a trauma, have a history of falls or aging disequilibrium, have
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vestibular or neurological disorders such as multiple sclerosis, Parkinson’s
disease, or have suffered a sports-related concussion.8-13
In order to maintain balance, the nervous system relies on input from 3
different subsystems, which are known as the visual, vestibular, and
somatosensory systems.14 The human body’s balance system continually receives
input from these subsystems, however, depending on the environmental
conditions, typically one predominates over the other.15 By providing disruptive
information that facilitates sensory conflict, the SOT can quantitatively assess the
patient’s ability to utilize each of the subsystems and maintain balance.16 The
ability of the SOT to detect impairments in these balance systems has been
documented in the literature.17-19 Yardley et al. has demonstrated that in patients
who complained of dizziness, tests of auditory, vestibular, and oculo-motor
function could not differentiate between dizzy subjects and matched controls,
while the SOT was capable of detecting impairments in these individuals.17
The MCT measures the patient’s ability to recover from unexpected
external perturbations. This movement induces an automatic postural response and
the onset timing, strength and lateral symmetry of responses are then recorded.7
This test measures the speed of a person’s reactions to external translations that
are provided by the force plate underneath the subject. There are 3 measures of
perturbations for this test rated as small, medium, large, which are always
performed in that order. The software tailors the size of each translation based on
the height of each patient. Lockhart et al. has demonstrated that those with longer
latency scores on the MCT have a less effective recovery method after
encountering a sudden slip.20,21
The ADT assesses if the patient can ignore disruptive somatosensory input
that occurs when a sudden and unexpected change in their support surface arises.
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The patient follows a normal learning curve during the 5 trials of this test, with
each successive trial demonstrating a decrease in sway energy, due to the
habituation of the automatic postural response and suppression of postural reflexes
by implementation of higher cognitive processes.7,22
Since the introduction of the NeuroCom EquiTest®, the literature has
confirmed the validity and utilization of the device in the diagnosis of balance
disorders in adults, making it the “gold standard” when testing balance on a
dynamic device.23-25 With the recent advances in technology, an alternative CDP
system by Bertec has become available. However, the normative data has yet to be
established.
One of the features integrated in Bertec’s new system making it appealing
to clinicians and researchers is the ability to use virtual reality (VR) in treatment
protocols, which has become an increasingly popular method of intervention.26 A
systematic review by Corbetta et al. found that rehabilitation which incorporates
VR is more effective than standard neurologic rehabilitation for improving
walking speed, balance and mobility after stroke.27 Virtual reality has also shown
promise in balance rehabilitation of patients with traumatic brain injury, diabetic
neuropathy, and those with peripheral vestibular disorders.28-30 Bertec’s new
platform is also capable of producing optokinetic stimuli, which when performed
with head tilts, has been demonstrated to be capable of readapting the vestibulo-
ocular reflex and improving debilitating conditions such as mal de debarquement
syndrome.31
The Bertec Balance Advantage® system utilizes a spherical dome that
immerses the user into a virtual surround environment through a projection.
During CDP testing, a major addition to the Bertec® is the virtual surround
environment to produce vection, which depicts the movement of large visual
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scenes in peripheral vision to cause an illusion of self-motion. Moreover, the
CDP’s virtual surround environment has the capability to create conflicting
sensory information within the body’s balance systems.32 One of the key features
of this surrounding spherical dome is its strong sense of presence of the
environment, which can help make a patient’s response in the virtual world similar
to their response in the real world.33 This sense of presence cannot be produced in
the NeuroCom®, as there is a lack of overhead projection within the device, thus
providing visual reference points, potentially providing the individual with visual
stability. The use of virtual surround environments to challenge balance and cause
postural sway has been documented in the literature, however, comparing it to the
NeuroCom EquiTest® sway reference to a visual surround on postural control has
not been studied.34
Normative values are currently available for the NeuroCom EquiTest® CDP
protocol from the ages of 20 to 79.7 Due to the Bertec’s platform differing from
NeuroCom® by using a virtual environment, it is unknown if the values between
the 2 devices are comparable. Currently to date, there is no normative data
available for the Bertec® Balance Advantage®. Therefore, the purpose of this study
is to report results on the CDP for healthy adults aged 20-69 using the Bertec®
Balance Advantage®.
Postural stability has been demonstrated to decline with age, while muscle
onset latency times have been shown to increase with age in studies using the SOT
and MCT performed on the NeuroCom EquiTest®, resulting in statistically
significant differences between age groups.20,35,36 To the best of our knowledge,
there are no studies that have investigated age differences on the ADT. We
hypothesize that there will be similar results using the new Bertec® Balance
Advantage®. Therefore, the null hypothesis is that there will be no differences
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between age groups on the SOT and MCT results using the Bertec® Balance
Advantage®. The alternative hypothesis is that there will be a significant
difference between age groups on the SOT and MCT results using the Bertec®
Balance Advantage®.
METHODS
Pilot Study
To help in determining test-retest reliability of the Bertec Balance
Advantage®, we tested 5 subjects aged 23-30 years of age who met the inclusion
criteria that is listed below on the SOT, MCT, and ADT. They performed all 3
tests for the CDP protocol, and then were retested 7 days later. Statistical analysis
was then completed with IBM SPSS version 24 software. Due to the large amount
of trials between ADT, the trials were combined into an averaged score in order to
compare between age groups.
Normative Study
Subjects
A total of 50 subjects were recruited for testing using non-probability quota
sampling. Subjects were recruited through the use of flyers, social media, and
word of mouth. An age range from 20 to 69 years of age was used. The subjects
were then stratified into 5 age groups, with 10 subjects in each group. Age groups
ranged from 20 to 29 years of age, 30 to 39, 40 to 49, 50 to 59, and 60 to 69.
This study was approved by the California State University, Fresno,
Committee on Protection of Human Subjects, and is in compliance with the
governmental regulations specified by the Office for Human Research Protection.
All subjects gave their informed consent prior to participation in this study (see
Appendix A).
Inclusion criteria consisted of any individual between 20 and 69 years of
age who did not have any significant medical history or known neurological or
musculoskeletal disorder or impairments that could impact balance. Exclusion
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criteria included the presence of dizziness, inner ear, or other balance or vestibular
disorder, open head injury, cervical injury, assistive device use or inability to stand
for periods shorter than 20 minutes, visual impairments that were worse than
20/40 with corrective lenses, a concussion within the past 10 years after which the
subject experienced headaches and/or other symptoms, diabetes, peripheral
vascular disease, any significant lower extremity joint disorder or injury, or
abnormal motion sickness and sensitivity.
All participants prior to testing were required to fill out a detailed subject
questionnaire to identify any potential conditions that would exclude them from
participation. Upon completion of the questionnaire, the subject’s height, age, and
sex were then recorded and inputted into the Bertec software (see Appendix B).
Procedure
The study used the new Bertec Balance Advantage® – Dynamic CDP
platform. Three tests were conducted on the Bertec system, the SOT, the MCT,
and the ADT. To reduce error, the same tester was used to conduct all 3
examinations.
Participants were equipped with a one-size-fits-all harness that was
adjusted to fit their body-type comfortably. They then were asked to remove their
socks and shoes and step onto the forceplates barefoot. The harness was then
attached to the safety straps that were hanging overhead, and the researcher then
aligned the participant’s medial malleolus into the standardized position, parallel
to the horizontal line on the forceplate. The lateral calcaneus of each foot was then
aligned to the small, medium, or large lines. The position of the lateral calcaneus
was dependent on the participant’s height, and the software instructed the
researcher where to align each participant’s feet. Detailed explanations of each test
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or trial was provided to each participant from a standardized script prior to
beginning any test, explaining what the test consisted of and to notify the
researcher if they began to feel dizzy or nauseous. Breaks were provided for each
patient between trials and conditions if they reported any of the aforementioned
symptoms and were not allowed to resume testing until symptoms subsided.
Participants were also instructed to wear their corrective visual lenses or contacts
if a physician prescribed them.
Sensory Organization Test
The SOT was the first test performed. This test records the movements of
the body’s CoP in 6 conditions, with 3 trials per condition. The tasks of each
condition are as follows; Condition 1: Participant’s eyes are open and there is a
fixed base of support and a fixed virtual environment. Condition 2: Participant’s
eyes are closed and a fixed base of support. Condition 3: Participant’s eyes are
open with a sway-referenced virtual environment and fixed base of support.
Condition 4: Participant’s eyes are open with a fixed virtual environment and a
sway-referenced mobile base of support. Condition 5: Participant’s eyes are closed
with a sway-referenced mobile base of support. Condition 6: Participant’s eyes are
open with a sway-referenced virtual environment and a sway-referenced mobile
base of support. The subject is placed on the platform and aligned in the position
as indicated by the software. Each trial lasted 20 seconds. The test then calculates
equilibrium scores for each trial, which is based on the displacement of the
subject’s COG over their BOS. A ratio score is then provided for each of the
sensory systems, as well as a composite score that provides a global determination
of normal versus abnormal results.7
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Motor Control Test
The MCT was performed immediately following the SOT unless
participants were feeling fatigued, dizzy, or requested a break. The MCT measures
the participant’s ability to quickly and automatically recover from unexpected
external provocations. The test used sequences of small, medium, or large
platform translations in either the forward or backward direction, however only the
medium and large translations are used for calculating test results. 3 trials of each
translation were performed. The participants first performed 3 small backward
translations, 3 medium backward translations, and 3 large backward translations.
The subjects then performed 3 small forward translations, 3 medium forward
translations, and 3 large forward translations. Each translation is automatically
scaled by the software according to the subject’s height. The software then
provides data on the time in milliseconds between the onset of the translation and
the force response in the subject’s legs, which is defined as latency, as well as an
overall composite score of the test.7 The subject’s foot alignment did not change as
compared to the SOT.
Adaptation Test
The ADT was performed last and immediately following the SOT and
MCT, unless the participants reported dizziness, fatigue, or requested a break. This
test assesses the participant’s ability to modify motor reactions and minimize sway
when the support moves in a toes-up or toes-down direction. The test includes 5
trials of the platform moving into an incline in the “toes up” direction, and then 5
trials of the platform moving into a decline or “toes down” direction. The
participants did not know when the platform was going to move during testing but
they were told in what direction it would be moving. For each of the trials, a sway
energy score quantifies the magnitude of the force response required to overcome
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the postural instability.7 The subject’s foot alignment remained the same as it was
on both the SOT and the MCT.
Data Analysis
Results of the SOT, MCT and ADT were analyzed using a one-way
analysis of variance (ANOVA) comparing age groups. All conditions, equilibrium
scores, ratio scores, and composite scores were analyzed for the SOT. MCT scores
were entered by averaging left and right scores together to be consistent with the
NeuroCom® normative values. ADT trials were averaged to determine differences
between age groups. Statistical significance of P < .05 was set for the ANOVA
analyses. If significance was found, a post hoc Tukey HSD was conducted to
determine which groups were different.
RESULTS
Reliability Pilot Study
Results for the test-retest reliability study were analyzed using a Pearson’s r
correlation coefficient and are listed in Tables 1 and 2 for the SOT, MCT, and
ADT. Using the Portney and Watkins guidelines, we defined values of less than
0.5 having poor reliability, 0.50 to 0.75 as having moderate reliability, and greater
than 0.75 as having good reliability.37 The results of the pilot study and the
category of each condition is summarized in Table 3.
Subjects
A total of 50 participants were used in the analysis of this study. Testing
began in January of 2016 and concluded in July of 2016. After a thorough
screening of the results of the 3 tests and subjective questionnaires, it was
determined that a total of 6 participants of the original 50 that were recruited were
not eligible to be included in the normative study due to previous major lower
extremity injuries such as ACL tears (2/6), a history of concussions (2/6), cervical
fusion (1/6), and prior unspecified lower back surgery (1/6).
An additional 6 participants were then recruited and testing began in
August of 2016 and concluded in November of 2016. Of the 50 participants, 17
were male and 33 were female. Less than half (19/50) participants had visual
impairments that were corrected with prescription lenses, while 14/50 participants
reported experiencing motion sickness at some point in their life, but follow up
questions helped determine it was not of enough concern to interfere with testing.
Nearly half (23/50) participants reported a prior LE injury and/or having a surgical
procedure done which included stress fracture repair, knee arthroscopy,
hysterectomy, caesarian section and appendectomy, while 15/50 participants
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reported using over the counter drugs such as multi-vitamins, ibuprofen,
probiotics, antihistamines and/or prescription drugs such as singular and zyrtex for
allergies, Lipitor and simvastatin for cholesterol; estrogen; thyroid medications,
Ventolin for bronchospasm, omperzole for gastroesophageal reflux disease,
Advair for COPD, and blood pressure medications such as Lisinopril and
Spurnolactin.
Comparison Between Age Groups
Normative values for all tests on the Bertec® can be found in Table 4. A
significant difference was found among the 5 age groups for condition 2 (P= .028)
and somatosensory ratio scores (P= .013) on the SOT using a one-way ANOVA.
The post hoc Tukey HSD revealed the differences were between the 20-29 age
group and the 50-59 age group for condition 2 (P= .037) and somatosensory ratio
scores (P=.009). Additionally, the 40-49 age group and 50-59 age group was also
significant for somatosensory ratio score (P= .037). Means and standard deviations
of groups for condition 2 and somatosensory ratio scores can be seen in Figures 1
and 2. The ANOVA analyses were not significant for all other SOT conditions,
ratio, or composite scores.
ANOVA analysis for MCT composite scores, medium and large forward
and backward translations were all determined to be insignificant between age
groups. No significant differences were found between age groups for toes up
average (P=.359), whereas the toes down average was determined to be
statistically significant (P=.025). A post hoc Tukey HSD revealed differences were
between the 20-29 age group and 50-59 age group (P=.048) and the 20-29 age
group and 60-69 age group (P= .029) All other age groups were determined to
have insignificant differences.
13 13
Comparison to NeuroCom® Normative Values
To determine if the SOT, MCT, and ADT scores using the Bertec® system
were comparable to those same scores on the NeuroCom®, we compared the
values against the published norms for NeuroCom®.7 Analyses comparing the
mean Bertec® scores in our sample to the reported mean value for each of the 3
measures will be performed by using the one-way t test.
When reviewing the results of the SOT and subsequently compare the 2
systems, the 60-69 age group was removed from the study and were grouped into
a 20-59 age group (n=40). A one-way t test comparing the 2 systems revealed
significant differences on condition 1 (P< .001), 4 (P< .001), 6 (P= .003) and
composite scores (P< .001) of the SOT. Means and standard deviations from
individual ADT trials were also calculated in order to directly compare to
NeuroCom® normative values.7 All MCT and ADT toes up scores were
determined to be significantly different (P < .05). Trials 2 through 5 of ADT toes
down were significantly different (P < .001), while trial 1 had no significant
difference. Comparison graphs are listed in Figures 3, 4, 5 and 6.
DISCUSSION
This is the first study to report normative values using the Bertec® Balance
Advantage® CDP platform. Test-retest reliability was moderate to good for all of
the results of our initial pilot study with the exception of the SOT on conditions 1
and 2 equilibrium scores, and somatosensory and vision ratio scores, along with
the ADT in the toes down direction. The ratio scores are calculated using the
results of condition 1, therefore having low reliability on condition 1 could
directly affect these scores.7 The most reliable conditions of the SOT were the
ones that are the most difficult, which is consistent with what has been reported.38
After reviewing the literature and to the best of the author’s knowledge, there are
no reliability studies currently available reporting on the MCT or ADT.
Significant differences were found in our normative study between age groups on
some equilibrium and ratio scores of the SOT, along with the toes down direction
of the ADT. Other authors have also reported differences across age groups in
healthy populations on the SOT using the NeuroCom® 35,36 There were no
significant differences found in any measures of the MCT, therefore, the
alternative hypothesis that there will be differences between age groups using the
SOT and MCT on the Bertec® Balance Advantage® is partially accepted.
The greatest differences between age groups were for condition 2 on the
SOT, as well as the somatosensory ratio score (condition 2/ condition 1). In part
this may be due to the poor reliability found for conditions 1 and 2 from our pilot
study.39 A study from Cohen et al. found that Condition 2 scores had low
variability among young subjects, but was demonstrated to decrease with age, and
it is known that older adults use different strategies to maintain balance when
compared to their younger counterparts.36,40 The fact that there were no significant
15 15
differences between the 60-69 age group and younger age groups is an unexpected
finding. Condition 2 is known to challenge the somatosensory system, and it is
possible that some participants had underlying conditions that may have been
unknown to them and thus were unable to report, such as peripheral neuropathy,
which is a risk factor for falls and postural instability.41 It is also possible that
some subjects were more physically active or participated in hobbies that
improved balance, as studies have demonstrated that these can have positive
effects on their balance.42-44 For example, our sample of 60-69 year olds actually
performed better across all conditions in the SOT as compared to the 50-59 year
old group.
The data gathered indicate similar values to that reported in the in the
NeuroCom® system, however, statistical significance was found between our
mean values and those reported for the NeuroCom® using a one-way t-test.7 These
include conditions 1, 4, 6 and composite scores of the SOT, along with all of the
MCT and ADT scores.
When compared to the NeuroCom® SOT, the equilibrium scores in our
sample for conditions 1, 2, and 3 and 5 are nearly identical to the reported
NeuroCom® normative values.7 The greatest differences between systems occurred
on condition 4 in the SOT. Although significant differences were found on other
conditions when testing with a one-way t-test, the differences are not clinically
important considering the learning effects that have been reported on the
NeuroCom®. A study conducted by Wrisley et al. found that the minimal
detectable change on the NeuroCom® SOT was 8 points due to the learning
effects, and all of the scores that were found to be significantly different with the
one-way t-test were below 8 points, with the exception of condition 4.38 A possible
explanation for this finding is that this condition is more posturally challenging on
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the Bertec® as compared to the NeuroCom®, because of the introduction of the
virtual surround. Condition 4 involves the subject’s eyes being open, heavily
relying on visual and vestibular input.
There were no significant differences in the overall composite scores of the
MCT or any of the latency translation scores in the forward or backward directions
across age groups in our normative study. This differs from a study conducted by
Lockhart et al., where they found significant differences between young, middle,
and old age groups when using MCT latency scores.20 However, in Lockhart et
al’s study, medium and large translation scores were combined.
To be consistent with the NeuroCom® normative data for comparisons, we
chose to analyze the medium and large translations separately. When comparing
the Bertec’s® MCT means to the established NeuroCom® norms, they are
relatively close to each other, with never more than 10 msec of a difference,
however all were determined to be significantly different with the one-way t-test.
One difference is between the platforms, as informed by the Bertec® corporation,
is that the Bertec® scores latencies within 5 msec, whereas the NeuroCom® system
is not that sensitive, and therefore, affects the latency score as much as 10 msec.
Thus, differences less than 10 msec between the 2 systems would be considered
comparable.
There was a significant difference in the toes down direction of the ADT
scores between age groups of the normative study. These differences occurred in
the 20-29 age group and 50-59 age group, as well as between the 20-29 age group
and 60-69 age group. It is known that if subjects have problems that are unrelated
to balance, such as anxiety, decreased ankle strength, and limited ankle range of
motion, the results of the ADT can be altered.7 The reliability of the ADT in the
toes down direction should also be taken into account when analyzing this finding,
17 17
as it had the poorest reliability score (r= 0.04) of all of the tests in the initial pilot
study.39 The ADT also demonstrates a high degree of variability, as is noted by the
large standard deviations that occur on each trial. This implies that this test should
be reviewed on more of a case-by-case basis, and should be examined by the
overall trend of the trials and not the exact score. There were no significant
differences between groups in the toes up direction of the ADT. The toes up
direction is the more researched component of the ADT, and it has been used in
the past to associate with certain neurological pathologies such as multiple
sclerosis.45,46
When comparing the means acquired on the ADT from the Bertec® to the
NeuroCom® norms, the intended trend can be seen. On both toes up and toes down
directions, there is normal suppression of the automatic reflexes across trials that
should occur during testing.7 In the toes down direction, the Bertec’s® standard
deviation values are within the norms of the NeuroCom®. When looking at the
toes up direction, there is a clear difference between both the Bertec® means and
the NeuroCom® norms. In order to fully understand this phenomena, more
information is required from the Bertec® corporation about the hardware. It is
known that the NeuroCom® rotates at a rate of 50º/second, while the Bertec’s® rate
of rotation was not known. Furthermore, there is a difference in the weight of the
forceplates between platforms, which could directly affect the amount of force that
is produced between both systems during the ADT test.
Limitations
For this study, a population of “healthy” individuals was required, and this
proved to be difficult to obtain. Many people today have had numerous surgeries,
conditions, or on medications that could impact or impair balance, especially when
18 18
dealing with elderly populations. In our sample for this study, we included 2
participants that had meniscal surgeries, as these were determined to be minimally
invasive arthroscopic surgeries and not impact proprioception or balance.
A quick sensory screen, such as a monofilament test or vibratory threshold
test, should have been conducted on patients to ensure proper proprioception of
lower extremities.47 If subjects had unknown underlying neuropathies or
conditions, it would have provided information to the researchers and they could
have excluded them from participating.
More information about lifestyle should also have been taken during the
questionnaire to give the researchers an idea of each subjects overall level of
fitness. It could have been asked in the form of how many hours per week subjects
participated in certain exercises and hobbies that have a positive effect on
balance.42-44 If a majority of the subjects in the 60-69 age group were actively
participating in such activities, and the 50-59 age group were less active, it could
have helped explain the differences in scores.
Conclusion
The results of this study indicate that the Bertec® Balance Advantage® can
remain consistent in detecting which individuals may be considered as “healthy”
and not have any balance deficits. The MCT and several conditions of the SOT are
comparable to the NeuroCom®, with the biggest differences occurring on
condition 4 of the SOT. Future research with healthy older adults should take into
account activity level of subjects, as some may be more physically active or have
hobbies that enhance balance and can create differences between age groups that
are not real.
19 19
Further studies are also necessary to determine the learning effects of the
SOT on the Bertec Balance Advantage® to determine its minimal detectable
change (MDC), as there may be a learning effect with repeated administration as is
seen on the NeuroCom Equitest.38 With the findings of significant differences on
conditions between both systems, the MDC’s could be different between platforms
as well. Test-retest reliability should also be established, as our initial pilot study
included a small sample size of only 5 subjects.
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7. EquiTest® System Version 8.0 Data Interpretation Manual. NeuroCom®
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11. Nelson SR, Di Fabio RP, Anderson JH. Vestibular and sensory interaction
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12. Beckley D, Bloem B, Van Dijk J, Roos R, Remler MP.
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13. Guskiewicz KM. Assessment of postural stability following sport-related
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15. Shumway-Cook A, Woollacott MH. The growth of stability: postural
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16. Clendaniel RA. Outcome measures for assessment of treatment of the dizzy
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17. Yardley L, Burgneay J, Nazareth I, Luxon L. Neuro-otological and
psychiatric abnormalities in a community sample of people with dizziness:
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18. Di Girolamo S, Di Nardo W, Cosenza A, Ottaviani F, Dickmann A, Savino
G. The role of vision on postural strategy evaluated in patients affected by
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19. Guskiewicz KM. Postural stability assessment following concussion: one
piece of the puzzle. Clin J Sport Med. 2001;11(3):182-189.
20. Lockhart TE, Smith JL, Woldstad JC. Effects of aging on the biomechanics
of slips and falls. Hum Factors. 2005;47(4):708-729.
21. Shepard NT, Janky K. Computerized postural control assessment.
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22. Nashner L. Adapting reflexes controlling the human posture. Exp Brain
Res. 1976;26(1):59-72.
23. Ionescu E, Dubreuil C, Ferber-Viart CC. Physiological changes in balance
control of adults aged 20 to 60 years assessed with Equitest. Ann
Otolaryngol Chir Cervicofac. 2005;122(5):231-235.
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24. Dodd K, Hill K, Haas R, Luke C, Millard S. Retest reliability of dynamic
balance during standing in older people after surgical treatment of hip
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26. User Manual Version 1.0. Bertec® Balance Advantage®; 2014:76-81.
27. Corbetta D, Imeri F, Gatti R. Rehabilitation that incorporates virtual reality
is more effective than standard rehabilitation for improving walking speed,
balance and mobility after stroke: a systematic review. J Physiother.
2015;61(3):117-124.
28. Cuthbert JP, Staniszewski K, Hays K, Gerber D, Natale A, O'Dell D.
Virtual reality-based therapy for the treatment of balance deficits in patients
receiving inpatient rehabilitation for traumatic brain injury. Brain Inj.
2014;28(2):181-188.
29. Grewal GS, Sayeed R, Schwenk M, et al. Balance rehabilitation: promoting
the role of virtual reality in patients with diabetic peripheral neuropathy. J
Am Podiatr Med Assoc. 2013;103(6):498-507.
30. Bergeron M, Lortie CL, Guitton MJ. Use of Virtual Reality Tools for
Vestibular Disorders Rehabilitation: A Comprehensive Analysis. Adv Med.
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31. Dai M, Cohen B, Smouha E, Cho C. Readaptation of the vestibulo-ocular
reflex relieves the mal de debarquement syndrome. Front Neurol.
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32. Thurrell AE, Bronstein AM. Vection increases the magnitude and accuracy
of visually evoked postural responses. Exp Brain Res. 2002;147(4):558-
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33. Sadowski W, Stanney K. Presence in virtual environments. Handbook of
Virtual Environments:Design, Implementation, and Applications. Manwah,
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34. Piponnier J-C, Hanssens J-M, Faubert J. Effect of visual field locus and
oscillation frequencies on posture control in an ecological environment. J
Vis. 2009;9(1):13-13
24 24
35. Borah D, Wadhwa S, Singh U, Yadav SL, Bhattacharjee M, Sindhu V. Age
related changes in postural stability. Indian J Physiol Pharmacol.
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36. Cohen H, Heaton LG, Congdon SL, Jenkins HA. Changes in sensory
organization test scores with age. Age Ageing. 1996;25(1):39-44.
37. Portney LG, Watkins MP. Foundations of Clinical Research: Applications
to Practice. Vol 2: Prentice Hall Upper Saddle River, NJ; 2000.
38. Wrisley DM, Stephens MJ, Mosley S, Wojnowski A, Duffy J, Burkard R.
Learning effects of repetitive administrations of the sensory organization
test in healthy young adults. Arch Phys Med Rehabil. 2007;88(8):1049-
1054.
39. Lopez CO, Trueblood PR, Rivera M, Wubenhorst N. Normative data of the
sensory organization test, motor control test, and adaptation test on the
Bertec® Balance Advantage® in healthy adults. Paper presented in partial
fullfilment of the requirements for the degree of Doctor of Physical
Therapy; March, 2017; Fresno, California.
40. Alexander NB, Shepard N, Gu MJ, Schultz A. Postural control in young
and elderly adults when stance is perturbed: kinematics. J Gerontol.
1992;47(3):M79-M87.
41. Richardson JK, Hurvitz EA. Peripheral neuropathy: a true risk factor for
falls. J Gerontol Series A: Biol Sci Med Sci. 1995;50(4):M211-M215.
42. Douris P, Southard V, Varga C, Schauss W, Gennaro C, Reiss A. The
Effect of Land and Aquatic Exercise on Balance Scores in Older Adults. J
Geriatr Phys Ther. 2003;26(1):3-6.
43. Schmid AA, Van Puymbroeck M, Koceja DM. Effect of a 12-week yoga
intervention on fear of falling and balance in older adults: a pilot study.
Arch Phys Med Rehabil. 2010;91(4):576-583.
44. Jeter PE, Nkodo A-F, Moonaz SH, Dagnelie G. A systematic review of
yoga for balance in a healthy population. J Alt Comp Med. 2014;20(4):221-
232.
45. Lawson GD, Shepard NT, Oviatt DL, Wang Y. Electromyographic
responses of lower leg muscles to upward toe tilts as a function of age. J
Vest Res. 1994;4(3):203-214.
25 25
46. Diener H, Dichgans J, Hülser P-J, Buettner U-W, Bacher M, Guschbauer B.
The significance of delayed long-loop responses to ankle displacement for
the diagnosis of multiple sclerosis. Electroencephalo Clin Neurophysiol.
1984;57(4):336-342.
47. Sorman E, Edwall LL. Examination of peripheral sensibility. Vibration test
is more sensitive than monofilament test. Lakartidningen.
2002;99(12):1339-1340.
TABLES
27 27
Table 1. Reliability Values of the SOT from Initial Pilot Study
SOT r-value (P<.05)
Condition 1 0.21
Condition 2 0.15
Condition 3 0.55
Condition 4 0.89
Condition 5 0.76
Condition 6 0.99
Somatosensory Ratio (2/1) 0.34
Vestibular Ratio (5/1) 0.52
Vision Ratio (4/1) 0.34
Preference Ratio (3+6/2+5) 0.83
28 28
Table 2. Reliability Values of MCT and ADT from Pilot Study
MCT and ADT Results r-value (P<.05)
MCT Back Medium 0.76
MCT Back Large 0.65
MCT Forward Medium 0.60
MCT Forward Large 0.88
MCT Composite 0.95
ADT Toes up 0.71
ADT Toes Down 0.04
Table 3. Reliability Categories of Initial Pilot Study for All Conditions
Category Tests
0.75 and up (Good) SOT: Condition 4, 5, 6, Composite, Preference
MCT: Composite Score, Forward Large, Backward
Medium
0.5-0.75 (Moderate) SOT: Condition 3, Vestibular
ADT: Toes Up Direction
MCT: Backward large, Forward medium
Less than 0.5 (Poor) SOT: Condition 1, Condition 2, Somatosensory, Vision
ADT: Toes Down Direction
29 29
Table 4 Means ± SD for SOT Equilibrium and Ratio Scores, MCT Latencies,
and ADT Averaged Sway Energy Scores for All Age Groups
Tests 20-29 y.o. 30-39 y.o. 40-49 y.o. 50-59 y.o. 60-69 y.o.
SOT 1 92.47±2.20 93.37±1.74 92.27±1.74 92.97±1.48 92.33±1.67
SOT 2 92.97±1.32* 92.83±2.18 92.30±1.09 90.50±2.43* 91.80±1.93
SOT 3 91.70±1.67 92.10±2.30 90.10±4.48 89.03±4.19 91.37±2.85
SOT 4 76.63±5.60 73.13±9.68 70.67±11.30 68.77±9.50 70.40±5.56
SOT 5 70.50±10.52 67.10±11.30 62.87±10..47 63.93±9.38 65.27±8.41
SOT 6 68.50±9.45 60.47±13.17 54.17±9.60 61.50±9.86 62.33±10.23
SOT Comp 79.18±4.67 76.05±7.06 72.58±6.09 73.85±6.62 75.12±4.32
SOM 100.60±2.55* 99.40±2.17 100.10±1.79* 97.40±2.12* 99.50±1.35
Vestibular 76.60±11.60 71.90±11.51 68.10±10.59 68.70±9.33 70.60±8.77
Vision 82.90±5.36 78.40±9.37 75.80±13.31 73.80±9.22 76.20±5.33
Preference 103.61±7.50 101.49±3.48 98.84±8.22 100.34±9.01 102.95±5.64
ADT Up 86.44±14.03 77.40±20.06 78.14±23.47 82.40±13.49 92.84±22.07
ADT Down 47.58±6.80* 58.84±24.00 60.04±9.62 70.66±21.27* 72.28±21.61*
MCT Comp 130.50±5.91 125.5±3.89 132.80±7.51 130.90±8.18 128.20±7.21
MCT B Med 127.35±9.74 124.35±6.52 131.40±9.15 131.05±7.85 127.85±7.59
MCT B Lrg 124.75±6.26 124.10±3.58 131.30±6.78 128.90±6.20 127.50±6.79
MCT F Med 135.50±6.32 128.00±7.49 135.70±6.57 131.40±10.62 130.90±10.66
MCT F Lrg 134.65±6.96 124.80±6.02 132.20±11.42 130.25±10.14 126.80±8.94
p values for comparing age groups *Asterisks indicate significant differences (p<.05) between age groups
FIGURES
31 31
Figure 1. Sensory organization test condition 2 means and standard
deviations comparing age groups
Figure 2. Somatosensory equilibrium scores given in means and standard
deviations comparing age groups
75
80
85
90
95
100
20-29 y.o. 30-39 y.o. 40-49 y.o. 50-59 y.o. 60-69 y.o.
Sensory Organization Condition 2
**
*Asterisks indicate significant differences
75
80
85
90
95
100
105
20-29 y.o. 30-39 y.o. 40-49 y.o. 50-59 y.o. 60-69 y.o.
SOT Somatosensory Equilibrium Scoresø*
ø*
ø Symbols represent groups that were significantly different from each other. *
32 32
Figure 3. SOT Bertec® means compared to NeuroCom® norms7
Figure 4. MCT Bertec® means and standard deviations compared to
NeuroCom® norms7
*
**
*
0
10
20
30
40
50
60
70
80
90
100E
qu
ilib
riu
m S
core
SOT Means 20-59 year old
Bertec (N=40)
NeuroCom (N=112)
*Asterisks indicate significant differences between platforms
0
20
40
60
80
100
120
140
160
180
M Back L Back M Forward L Forward
Tim
e (
mse
c)
MCT Latencey Means 20-59 y.o.
Bertec N=40
NeuroCom=29
***
*
*Asterisks indicate significant differences between platforms
33 33
Figure 5. Comparison of toes up means and standard deviations of sway
energy scores on Bertec® compared to NeuroCom® norms7
Figure 6. Comparison of toes down means and standard deviations of sway
energy scores on Bertec® compared to NeuroCom® norms7
0
20
40
60
80
100
120
140
T1 Avg T2 Avg T3 Avg T4 Avg T5 Avg
Sw
ay
En
erg
y S
core
Toes Up Means 20-59 years old
Bertec (N=40)
NeuroCom(N=64)
*
* *
*
*
*Asterisks indicate significant differences between platforms
0
20
40
60
80
100
120
T1 Avg T2 Avg T3 Avg T4 Avg T5 Avg
Sw
ay
En
erg
y S
core
Toes Down Means 20-59 years old
Bertec (N=40)
NeuroCom (N=64)
*
* **
*Asterisks indicate significant differences between platforms
APPENDICES
APPENDIX A: STUDY IRB
36 36
I.D.#
FRESNO STATE PHYSICAL THERAPY DEPARTMENT
PARTICIPANT CONSENT FORM
Project Title: Computerized Posturography using the Bertec in Healthy
Adults
Principal Investigator: Peggy R. Trueblood, PhD, PT
Professor and Chair
Department of Physical Therapy
Co-Investigators: Marcia Thompson, DSc, DPT
Assistant Professor, Department of Physical Therapy
Leslie Zarrinkhameh, PT, DPT, GCS
Lecturer, Department of Physical Therapy
Toni Tyner, MHL, PT
Assistant Professor, Department of Physical Therapy
Student Investigators: Carolyn Bentley, SPT
Christian Lopez, SPT
PURPOSE OF RESEARCH
I have been informed that the overall purposes of this project are to collect normative
data on a new posturography system that measures a person’s balance and to compare
this system to the gold standard system, also measuring your balance or postural control.
More specifically, we will 1) collect normative data using the Bertec Computerized
Dynamic Posturography (CDP) system using virtual reality with images projected in a
specially modified dome and 2) compare this data with the sway-referencing used by
EquiTest systems developed by NeuroCom International. The images used in the Bertec
system are controlled by the system’s computer and move in correspondence to your
postural sway detected by a force plate that you will stand on during the protocols. The
image is concentric ovals leading to a grey oval shape, creating the perception of a tunnel
with no definable end or horizon during the Sensory Organization test. In the case of the
37 37
EquiTest system by NeuroCom, the dome is referenced by your postural sway on the
forceplate.
I acknowledge that my participation is voluntary and will include a 60 minute collection
period (approximately 30 minutes with each system). The project will be conducted in
McLane 104 and 111, the Department of Physical Therapy at California State University,
Fresno.
CRITERIA FOR PARTICIPATION
I am eligible to participate in this study if I meet the following criteria: 1) age 20-59
years old without any significant medical history or known neurological or
musculoskeletal disorder/impairment that can impact my balance. I am aware that I will
be ineligible to participate in this study if I do not meet the criteria noted above and/or
have a prior history of any of the following: 1) dizziness, inner ear, or other balance or
vestibular disorder, 2) closed or open head injury, 3) cervical injury, 4) assistive device
use or inability to stand for 20 minutes, 5) visual impairment (worse than 20/40 with
corrective lenses), 6) concussion after which I experienced headaches and/or other
symptoms, 7) diabetes, 8) peripheral vascular disease, 9) any significant lower extremity
joint disorder or injury, 10) motion sickness/sensitivity.
PROCEDURE
I am aware that I will be:
1. Screened using a questionnaire to determine my eligibility before testing.
2. If eligible for testing, my name will be entered as a code name, eg Fresno 101,
102, etc into the computerized systems that test your balance
3. My age, sex, height information will be entered in the systems. These parameters
are used to determine proper foot placement.
4. I will be provided standard instructions prior to the start of each test condition
including the start of each test. During the recordings, I will maintain a steady
standing position.
5. I will be tested on two different computerized systems, each using 3 different tests
to measure balance: Sensory Organization Test (SOT); Adaptation Test (ADT)
and the Motor Control Test (MCT).
6. I will be tested without shoes. The investigator will align my feet properly at the
beginning of the tests.
7. I am allowed to rest as often as necessary throughout the testing.
8. During some of the tests the support surface and or the visual surround may move
gently during some of the recording trials. My task will be to remain as steady as
possible. The investigator will inform me when this may occur.
9. During all of the testing, I will be in a restraining harness and the investigator will
remain in close proximity in case I lose my balance.
38 38
10. The entire session will take approximately 30 minutes on each system. I will have
a 15 minute rest period between testing on the two balance systems.
11. I will first perform all of the standing balance tests on the Bertec System in the
following order:
a) First, I will complete the Sensory Organization Test (SOT) This balance test
systematically tests our three sensory systems: vision, vestibular or inner ear, and
somatosensory or our sensation of our feet. During the SOT, I will complete 3, 20
second trials of six different test conditions (18 total trials) during the Sensory
Organization Test. I will be allowed to rest between conditions as needed. The
order of testing is as follows:
i. Eyes open with a fixed (i.e. not moving) surface and visual
surround
i. Eyes closed with a fixed surface
ii. Eyes open with a fixed surface
iii. Eyes open with a fixed surface and sway-referenced (i.e., moving)
visual surround
iv. Eyes open with a sway-referenced surface and fixed visual
surround
v. Eyes closed with a sway-referenced surface
vi. Eyes open with a sway-referenced surface and visual surroundings.
b) Next I will perform the Motor Control Test (MCT). This test is designed to assess
my ability to recover automatically from external perturbations or slight
movements under my feet. The scale of the movement is based on my height.
This test will also include six different conditions, 3 trials each, which are as
follows:
i. Backward translation, small
ii. Backward translation, medium
iii. Backward translation, large
iv. Forward translation, small
v. Forward translation, medium
vi. Forward translation, large
c) The final test I will perform is known as the Adaptation test (ADT). This test
measures my ability to counteract a movement of the surface that I am standing
on in a toes up or toes down direction. I will be given 5 trials of each condition
(toes up and toes down).
2) I will have a 15 minute rest period before repeating these tests on the NeuroCom
System.
39 39
BENEFITS
I understand that there is no benefit in my participation in this project except to have my
balance tested on two different, but similar computerized systems. My participation will
add to the normative database for a new computerized balance system on the market and
will help determine if there are differences in the balance scores as compared to the gold
standard system already in use.
RISKS AND DISCOMFORTS
Risks associated with the balance tests are minimal. I am aware that participation in this
project may lead to fatigue or dizziness. To avoid this, rest breaks will be allowed. I
understand that there is a possibility that I may lose my balance at times during the
assessments. To prevent a fall or loss of balance, I will wear a safety harness for all
testing and will be guarded by trained investigators.
CONFIDENTIALITY
I understand that the findings of this study will be kept confidential and will be stored in
a secure location. Should the data be used for publication in medical literature or for
teaching purposes, I understand that only the investigators will know my identity and I
will not be identified by my name in any publication. I further understand that
photographs and videotapes will be used only with my written permission.
REQUEST FOR MORE INFORMATION
I understand that I have the right to ask and have answered questions concerning this
study at any time. Dr. Peggy Trueblood, the principal investigator, is available to answer
my questions or concerns at 278-3008. I will receive a copy of this consent form to refer
to for further reading or clarification if needed.
REFUSAL OR WITHDRAWAL OF PARTICIPATION
I understand that my participation is voluntary and that I may refuse to participate or
withdraw consent and discontinue participation in this study at any time. I also
understand that the investigators may terminate my participation in this study at any time
after they have explained the reasons for doing so.
INJURY STATEMENT
I understand that in the event of any physical injury resulting from my participation in
this study, my physician will be notified and treatment will be available at my own
expense. There will be no form of legal or monetary compensation available from the
California State University, Fresno, my referring physician, or the above listed
investigators.
40 40
I have explained to ______________________________ the purpose of this study, the
procedures, and the possible risks and benefits to the best of my ability.
______________________________ ______________________
Investigator Date
CONSENT
I confirm that the investigators have explained to me the purpose of the project, interview
process, screening, and procedures that I will undergo. I also understand the possible
risks and benefits that I may experience as a result of this study. The procedures for this
research have been reviewed and approved by California State University, Fresno,
Committee on Protection of Human Subjects. I have read and understand this consent
form. Therefore, I agree to give my consent to participate as a subject in this project.
______________________________ ______________________
Participant Date
______________________________ ______________________
Witness to Signature Date
I do/do not authorize the taking of photographs or videotapes of myself for either
publication or use as educational materials.
_____________________________ ______________________
Participant Date
_____________________________ ______________________
Witness to Signature Date
41 41
I.D.#
MEDICAL RESEARCH PATIENT’S BILL OF RIGHTS
California law requires that any person asked to take part as a subject in research
involving a medical experiment, or any person asked to consent to such participation on
behalf of another, is entitled to receive the following list of rights written in a language in
which the person is fluent. This list includes the right to:
1. Be informed of the nature and purpose of the experiment.
2. Be given an explanation of the procedures to be followed in the medical experiment
and any drug or device to be utilized.
3. Be given a description of any attendant discomforts and risks reasonably to be
expected from the experiment.
4. Be given an explanation of any benefits to the subject reasonably to be expected from
the experiment, if applicable.
5. Be given a disclosure of any appropriate alternative procedures, drugs, or devices that
might be advantageous to the subject, and their relative risks and benefits.
6. Be informed of the avenues of medical treatment, if any, available to the subject after
the experiment if complications should arise.
7. Be given an opportunity to ask any questions concerning the experiment or the
procedures involved.
8. Be instructed that consent to participate in the medical experiment may be withdrawn
at any time and the subject may discontinue participation in the medical experiment
without prejudice.
9. Be given a copy of the signed and dated written consent form.
10. Be given the opportunity to decide to consent or not to consent to a medical
experiment without the intervention of any element of force, fraud, deceit, duress,
coercion, or undue influence on the subject’s decision.
APPENDIX B: HEALTH QUESTIONNAIRE
43 43
Subject Questionnaire Computerized Posturography using the Bertec in Healthy Adults
1) Have you experienced dizziness or been diagnosed with inner ear or any other
balance or vestibular disorder?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
2) Have you a prior head injury, open or closed?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
3) Have you had any prior cervical injury?
[ ] Yes [ ] No
4) Do you currently use an assistive device (e.g cane)?
[ ] Yes [ ] No
5) Are you able to stand unsupported for a minimum of 20 minutes?
[ ] Yes [ ] No
6) Do you have any visual impairments?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
7) Have you had a concussion after which you experienced headaches and/or other
symptoms?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
8) Have you been diagnosed with diabetes?
[ ] Yes [ ] No
9) Have you been diagnosed with peripheral vascular disease?
[ ] Yes [ ] No
10) Have you had any significant lower extremity joint disorder or injury?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
44 44
11) Have you experienced any motion sickness or sensitivity?
[ ] Yes [ ] No
12) History of any neurological disease?
[ ] Yes [ ] No
13) Any history of surgeries?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
14) Any recent illnesses or ear infections?
[ ] Yes [ ] No
If Yes, please explain
_________________________________________________________
15) Have you consumed any alcohol in the past 12 hours?
[ ] Yes [ ] No
16) Please list (or provide) your current prescribed and/or over-the-counter medications.
_____________________________________________________________________
_____________________________________________________________________
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I, _____________________________, confirm that the above information is true to my
knowledge.
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Participant Date
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Witness to Signature Date