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Neurocognitive Aspects of Sports Injury Prevention & Rehabilitation

Assessment of Injury Risk

Gary Wilkerson, EdD, ATC

American Academy of Physical Medicine & RehabilitationOctober 2, 2015

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Research Evidence: Injury Risk Factors

1.Volume of Exposure to High-Stress Activities Gender; Age; Sport; Position; Level of Competition

2.Previous Injuries Incomplete recovery; Pre-injury functional

deficiencies

3.Anthropometric Characteristics Body mass to height relationship; Structural

alignment

4.Mobility (Muscle Flexibility/Joint Stability) General joint hypermobility; Ligament laxity

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Research Evidence: Injury Risk Factors

5.Neuromuscular Performance Capabilities Core stability; Postural balance; Strength;

Agility

6.Reaction Time Neurocognitive; Visuomotor

7.Psychosocial Stress Anxiety; Depression, Negative life events

8.Behavioral Factors Sleep quality; Dietary habit

Interrelationships Among Determinants of Injury Susceptibility

↑ Core & LE Sprain/Strain

Injury Risk

Previous Core or LE Injury

Slow Reaction

Time

Malalignment and/or

Asymmetry

↑ Processing

Time (Latency)

Ligament Laxity

(↓ Stiffness)

↓ Strength and

Endurance

↓ Agility(Avoid Impact)

↓ Postural Balance

ArthrogenicMuscle

Inhibition

↑ EMD

↓ Spindle Sensitivity

Y BalanceAnt. Reach

Wall SitHold

ImPACT Test

High Exposure to CompetitiveEnvironment

↓ Muscle Splinting

(Cocontraction)

LESCA Survey

↑ Moment

Arm

Depression

Anxiety

Negative Life Events

Low Self-Efficacy

Unfavorable Mass – Height Relationship

Suboptimal Neuromuscular

Function

PsychosocialStress

Joint Hypermobility

kg x m2

Horizontal Trunk Hold

↑ Loading Frequency

Injury Hx Survey

SuddenUnexpected

Loading

↓ Peripheral

Vision

↓ Mobility

FunctionalMovement

Screen

LESS

↓ Mental Focus

kg / m2

2009 – 2011 Football Core/LE Sprains & StrainsLow Back Strain/S-I Sprain 9

Abdominal/Hip Flexor/Groin Strain 36

Hamstring Strain 15

Quadriceps Strain (Distal Thigh) 3

Knee MCL Sprain 10

Knee ACL Tear 3

Knee PCL Tear 1

Knee Meniscus/Osteochondral Lesion

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Knee Hyperextension Sprain 1

Patello-Femoral Sprian/Subluxation 3

Achilles Tendon Strain 1

Lateral Ankle Sprain 27

Syndesmosis (High Ankle) Sprain 10

Medial Ankle Sprain 1

Mid-Foot Sprain 6

First Metatarsophalangeal Sprain 3

Total Core + LE Injuries 132*

* 29 players sustained >1 injury during same season40% of players (103/256) sustained at

least 1 injury during a given season (2009 – 2011)

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2009 – 2011Wall-Sit Hold Modifications

Mean = 79 s SD = 34 s

2009 N = 83

≤ 60 sOR=2.08

Mean = 61 s SD = 27 s

2010 N = 88

≤ 45 sOR=2.18

Mean = 28 s SD = 14 s

2011 N = 85

≤ 30 sOR=2.04

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2009 – 2011 Combined Analysis3-Factor Prediction Model N=256

Injury No Injury

% Injured

≥ 2 Factors 58 30 66%0 or 1 45 123 27%

Total 103 153Fisher’s Exact One-Sided p < .001

Sensitivity= 56%

Specificity= 80%

OR = 5.3 90% CI: 3.31 – 8.44

1. Starter (≥1 game) 2. Hi ODI (≥4) 3. Lo WSH (≤88-41-30 s)

Wilkerson GB, Colston MA. A refined prediction model for core and lower extremity sprains and strains among collegiate football players. J Athl Train. 2015;50:doi: 10.4085/1062-6050-50.2.04.

Risk Factor

s

Injury

No Injur

y

Incidence

0 9 47 16%

1 36 76 32%

2 45 25 64%

3 13 5 72%

Total 103 153 40%

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Relationship of Core Stability to Lower

Extremity Injury Risk Alteration of posture changes the center of

mass location over the base of support Generation of muscle tension required to counteract

external moments acting on joints

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Postural Sway – Unilateral Squat HoldA-P Postural Inertia Variability (Jerk SD; 60-s test)

Injury No Injury

% Injured

≥ .024 34 32 52%

< .024 4 19 17%

Total 38 51Sensitivity 90% Specificity 37%

OR = 5.190% CI: 1.87 – 13.60

2014 N=89Core or LE Sprain or Strain

45° Knee Flexion1” Heel

Elevation

Neurocognitive Reaction TimeSwanik et al. Am J Sports Med. 2007

Pre-season assessment of college athletes at 18 universities 80 non-contact ACL tear cases (45 female, 35 male) 80 matched controls (gender, height, weight, age, sport,

position)

Non-contact ACL tear cases compared to controls –

Composite Reaction TimeCases: 570 msControls: 530 ms

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2011 Neurocognitive Reaction TimeWilkerson GB. Neurocognitive reaction time predicts lower extremity sprains and strains.Int J Athl Ther Train. 2012.

InjuryNo

Injury%

Injured

≥ 545 ms

18 29 38%

< 545 ms 6 27 18%

Total 23 52Fisher’s Exact One-Sided p =.044

Sensitivity = 75%

Specificity = 48%

OR = 2.8 90% CI: 1.15 – 6.81

≥ 545 ms

Core + LE Strains & Sprains

AUC = .57

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Concussion – MSK Injury Incidence Herman et al, 2013, Clin J Sports Med

College athletes with concussion Hx (n=49) vs. matched controls (n=90) LE sprain or strain; Men’s Football + Women’s Basketball, Soccer, & Lacrosse 90-day period: 46% of cases injured vs. 17% of controls injured; RR = 2.7

Nordstrom et al, 2014, Br J Sports Med Male soccer players with concussion Hx (n=66) vs. no concussion Hx

(n=1599) 12-mo post-concussion surveillance period; any MSK injury 11.5 ±8.6 vs. 5.0 ±5.2 injuries; RR = 2.2

Pietrosimone et al, 2015, Med Sci Sports Exerc Retired NFL football players (n=2429); concussion history prevalence 61% LE MSK injury # - adjustment for years played, BMI (during career), &

position Concussions 1 vs. 0: OR = 1.6; 2 vs. 0: OR = 2.3; 3 vs. 0: OR = 2.9

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Concussion – MSK Injury Incidence

Lynall et al, 2015, Med Sci Sports Exerc “Acute lower extremity injury rates increase

following concussion in college athletes.”Concussion Hx (n=44) vs. matched controls

(n=58)13 Sports – Cases: 28 M/16 F; Controls: 39 M/19 FLE MSK injuries 1 year pre & post concussion

occurrence Incidence rate per 1000 AEs

Cases vs. Controls Pre: 1.78 / 2.56 RR = 0.7 Cases vs. Controls Post: 3.51 / 2.14 RR = 1.6 Cases Post vs. Pre: 3.51 / 1.78 RR = 2.0

Concussion History Association withCore or Lower Extremity Sprain or Strain

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Injury No Injury

% Injured

YES 12 8 60%

NO 26 43 38%

Total

38 51

Sensitivity 32% Specificity 84%

OR = 2.5 RR = 1.6

90% CI: 1.06 – 5.83

Injury No Injury

% Injured

YES 18 4 82%

NO 29 38 43%

Total

47 42

Sensitivity 38% Specificity 91%

OR = 5.9 RR = 1.9

90% CI: 2.18 – 15.96

2014 Top 20 FCS TeamN=89

2014 Top 20 FBS TeamN=89

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Time-Loss Core or LE Sprain or Strain

Risk Factors Injury No

InjuryInciden

ce

0 2 37 5%

1 15 18 46%

2 11 6 65%

Total 28 61

Butler MK, Madson HM University of Tennessee at Chattanooga Graduate Research Project, 2015

Hazard Ratio = 12.84

1 or 2 Factors

Neither Factor

2014 N=89 Risk Factors: 1) Core/LE Injury History2) Concussion History

FCS Team N=89

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Visual Target Detection Time

Elapsed time (ms) between target button illumination and release of depressed button (non-illuminated) Central focus maintained; central vs.

peripheral detection

A B C DCentral – Right Hand

Central – Leftt HandPeripheral – Right Hand Peripheral – Left Hand

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17 Concussion History Cases – 17 Matched Control Players (Football)

Scott AC, Varnell AD University of Tennessee at Chattanooga Graduate Research Project, 2015

Variable Cut-Point

Sensitivity Specificity Odds

Ratio 90% CI

Visual Memory Score (0-100) ≤ 73.5 65% 71% 4.40 1.31 - 14.75

Composite Reaction Time (ms) ≥ 675 29% 94% 6.67 0.99 - 44.94

Central Visual Detection (ms) ≥ 270 82% 41% 3.27 0.87 - 12.27

Peripheral Visual Detection (ms) ≥ 298 82% 41% 3.27 .0.87 - 12.27

Postural Inertia Variability (Jerk) ≥ .042 40% 87% 4.33 0.95 - 19.83

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Injury Risk Reduction Strategy

Evidence suggests that both CNS processing and generation of mechanical force can be accelerated

Visual Detection Central Processing Spindle Sensitivity

Sensory Input Integration with Memory = Anticipatory Muscle Activation

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Execution of Motor Commands

Propriospinal neurons Proprioceptive & cortical

inputs (excitatory & inhibitory)

Output α & MNs

1. Facilitation of excitatory pathways

2.Suppression of inhibitory pathways

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Prolonged Effects of Concussion Persistent alterations in brain function cannot

be detected by standard neuropsychological tests Chronic subclinical motor system dysfunction Intracortical inhibition of neural transmission

(GABAB)

De Beaumont et al. 2012, Cereb CortexDe Beaumont et al. 2012, Neurosurg FocusThériault et al. 2011, J Clin Exp NeuropsycholTremblay et al. 2011, J NeurotraumaDe Beaumont et al. 2007, NeurosurgMcDonell et al. 2006, Exp Brain Res

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Inhibition – Neuron Hyperpolarization

GABABGABAA

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Intracortical Inhibition

Post-concussion elevation of GABA activity believed to be a protective response against glutamate toxicity De Beaumont et al, 2012; Tremblay et al, 2011

Subclinical effects may persist for decades Despite normal neurocognitive test performance

Subtle long-term effects: Stimulus identification and proper response

selection Impairment of visual working memory Slowed reaction time Impairment of motor learning (decreased neuroplasticity)

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Subclinical Effects of Head Impacts Current tests insufficiently sensitive to detect

subtle changes (Talvage et al, 2014, J Neurotrauma)

Subconcussive head impacts are associated with significant fMRI changes (Breedlove et al, 2014, J Biomech)

Compensatory mechanisms may sustain normal cognitive/motor function (De Beaumont et al, 2012, Neurosurg Focus)

FB players with low visual/sensory performance sustain more severe head impacts (Harpham et al, 2014, Ann Biomed Eng)

Impairments may be more pronounced during multi-task assessment (Lynall et al, 2015, Med Sci Sports Exerc)

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Dual-Task Assessment

Imposition of simultaneous cognitive demand Slower RT, altered gait, and/or impaired postural balance

Howell et al, 2015, Med Sci Sports Exerc

Howell et al, 2015, J Biomech

Dorman et al, 2013, J Sci Med Sport

Lee et al, 2013, J Sci Med Sport

Register-Mihalik et al, 2013, Neuropsychol Rev

Teel et al, 2013, J Sci Med Sport

Al-Yahya et al, 2011, Neurosci Biobehav Rev

Catena et al, 2011, J Neuroeng Rehabil

Resch et al, 2011, J Athl Train

Ross et al, 2011, J Sport Rehabil

Catena et al, 2009, J Neuroeng Rehabil

Catena et al, 2007, Exp Brain Res

Parker et al, 2007, Br J Sports Med

Parker et al, 2006, Med Sci Sports Exerc

Parker et al, 2005, Clin Biomech

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≥ 705 ms

Visuomotor Reaction Time

Any Sprain or Strain*

Injury No Injury

% Injured

≥ 705 ms

22 20 52%

< 705 ms

11 23 33%

Total 33 43

Sensitivity 67% Specificity 54%

OR = 2.990% CI: 1.05 – 5.06

* Upper Extremity, Core, or Lower Extremity

2013 N=76

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6-Week VMRT Training Program16 120-s sessions (> 50% completion)

Baseline Follow-Up0

100

200

300

400

500

600

700

800

900

641 ms667 ms

792 ms

571 ms

Control Group (N=27) Training Group (N=15)

Vis

uo

mo

tor

Reacti

on

Tim

e (

ms)

Control: Faster than Baseline Median Value (< 705 ms)

221 ms

134 ms

87 ms

64 ms

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Neurocognitive vs. Visuomotor RTCore or Lower Extremity Sprain or Strain

2014 N=52

InjuryNo

Injury%

Injured

≥ 743 ms

21 14 60%

< 743 ms 5 12 29%

Total 26 26

Sensitivity = 81%

Specificity = 46%

OR = 3.6 90% CI: 1.27 – 10.22

2014 N=52

InjuryNo

Injury%

Injured

≥ 655 ms

7 464%

< 655 ms

19 2246%

Total 26 26

Sensitivity = 27%

Specificity = 85%

OR = 2.0 90% CI: 0.64 – 6.42

RapidMultisegmental

Response

Visual Awareness of Environment

VisuomotorProcesses

Premotor Time

MotorTime

Neurocognitive Processes

StimulusDetection

StimulusDiscrimination

ResponseSelection

TaskExecution

Target Location(s) Cognitive Demand Task Complexity

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Psychosocial Stress

14% slower RT + 3.5% reduction in peripheral vision

Williams JM, Andersen MB. Psychosocial influences on central and peripheral vision and reaction time during demanding tasks. Behav Med. 1997:22(4):160-167.

Negative life events and narrowing of peripheral vision associated with injury incidence 196 NCAA Division I athletes

Andersen MB, Williams JM. Athletic injury, psychosocial factors and perceptual changes during stress. J Sports Sci. 1999;17(9):735-741.

LESCA Neg Score ≥ 14 39 NCAA Division 1-FCS football players

InjuryNo

Injury%

Injured

≥ 14 9 10 47%

<14 4 16 20%

Total 13 26

OR = 3.6 90% CI: 1.10 – 11.84

Henley SUniversity of Tennessee at Chattanooga, Graduate Research Project, 2011

Interrelationships Among Factors Influencing Responsiveness to Environmental Stimuli

NEUROCOGNITIVEEXECUTIVEFUNCTION

SLEEPQUALITY

DIETARYHABITS

MENTALSTATUS

Life EventsSurvey for CollegiateAthletes

PittsburghSleep

Quality Index

HealthyEating Index

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Movement Variability (MV)

Accumulating evidence supports MV as an indicator of adaptability to changing demands

Preatoni et al, 2013, Sports BiomechStergious & Decker, 2011, Hum Mov SciPollard et al, 2005, J Appl Biomech

Variability traditionally viewed as unexplainable “noise” that inflates measurement “error”

Alternate view: Low MV may be an indicator of suboptimal sensorimotor control

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Variability: Error vs. Hidden Pattern

Biological Signal (ECG, EEG) Movement Pattern

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Low MV – Post-Concussion Balance

Cavanaugh et al, 2006, J Athl Train Male + Female college athletes with

concussion (n=29) Baseline performance vs. 48-96 hours post-

concussion Low MV (COP) compared to pre-injury

baseline values

De Beaumont et al, 2011, J Athl Train College FB players: Cases (n=21) vs.

Controls (n=15) ≥ 9 months post-concussion (9 – 34

months, Avg = 19) Cases: Significantly lower MV in COP

oscillations (A-P)

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Inertial Sensor Data – Player LoadN=45 17 Weeks (12-Game Season)

An infinite variety of neuromuscular responses control relative positions of kinetic chain segments

Low MV (Load CoV ≤ 0.15): OR = 8.2 (ORAdj = 7.8) High Exposure (Plays ≥ 289): OR = 6.4 (ORAdj = 6.1)

NEUROMECHANICALRESPONSIVENESS TO INJURY POTENTIAL

MULTI-SEGMENTAL ALIGNMENT

BRAIN PROCESSING OF NEURAL

INPUT

POSTURAL BALANCE

MUSCLE STRENGTH & ENDURANCE

VISUOMOTOR REACTION

TIME

REFLEXIVE MUSCLE

RESPONSES

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Summary

1. Risk prediction models are highly specific to cohort characteristics and exact definition of “injury”

2. Core stability and reaction time appear to be potentially modifiable injury risk factors

3. Accumulating evidence of long-term post-concussion impairment of sensorimotor control processes

Gary-Wilkerson@utc.edu