Neurocognitive Aspects of Sports Injury Prevention - PowerPoint Presentation

Neurocognitive Aspects of Sports Injury Prevention & RehabilitationAssessment of Injury Risk Gary Wilkerson, EdD, ATC 1 American Academy of Physical Medicine & Rehabilitation October 2, 2015

Disclosure2Travel expense reimbursement for conference presentation sponsored by Dynavision, International (2014)

Research Evidence: Injury Risk Factors3Volume of Exposure to High-Stress Activities Gender; Age; Sport; Position; Level of CompetitionPrevious InjuriesIncomplete recovery; Pre-injury functional deficienciesAnthropometric CharacteristicsBody mass to height relationship; Structural alignment Mobility (Muscle Flexibility/Joint Stability)Ligament laxity; General hypermobility or hypomobility

Research Evidence: Injury Risk Factors4Neuromuscular Performance Capabilities Core stability; Postural balance; Strength; AgilityReaction TimeNeurocognitive; VisuomotorPsychosocial StressAnxiety; Depression, Negative life events Behavioral FactorsSleep quality; Dietary habits

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 Arthrogenic Muscle Inhibition ↑ EMD ↓ Spindle Sensitivity Y Balance Ant. Reach Wall Sit Hold I mPACT Test High Exposure to Competitive Environment ↓ 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 m 2 Horizontal Trunk Hold ↑ Loading Frequency Injury Hx Survey Sudden Unexpected Loading ↓ Peripheral Vision ↓ Mobility FunctionalMovementScreen LESS ↓ Mental Focus kg / m 2

2009 – 2011 Football Core/LE Sprains & StrainsLow Back Strain/S-I Sprain 9 Abdominal/Hip Flexor /Groin Strain36 Hamstring Strain 15 Quadriceps Strain (Distal Thigh) 3 Knee MCL Sprain 10 Knee ACL Tear 3 Knee PCL Tear 1 Knee Meniscus/ Osteochondral Lesion 3 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 3Total Core + LE Injuries 132* * 29 players sustained >1 injury during same season 40% of players (103/256) sustained at least 1 injury during a given season (2009 – 2011)

2009 – 2011Wall-Sit Hold Modifications7 Mean = 79 s SD = 34 s 2009 N = 83 ≤ 60 s OR = 2.08 Mean = 61 s SD = 27 s 2010 N = 88 ≤ 45 s OR = 2.18 Mean = 28 s SD = 14 s 2011 N = 85 ≤ 30 s OR = 2.04

2009 – 2011 Combined Analysis3-Factor Prediction Model N=2568 Injury No Injury % Injured ≥2 Factors 58 30 66% 0 or 1 45 123 27% Total 103 153 Fisher’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 Risk Factors Injury No Injury Incidence 0 9 47 16% 1 36 76 32% 2 45 25 64% 3 13 5 72% Total 103 153 40%

Relationship of Core Stability to Lower Extremity Injury Risk9Alteration 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

Postural Sway – Unilateral Squat HoldA-P Postural Inertia Variability (Jerk SD; 60-s test)10 Injury No Injury % Injured ≥ .024 34 32 52% < .024 4 19 17% Total 38 51 Sensitivity 90% Specificity 37% OR = 5.1 90% CI: 1.87 – 13.60 2014 Football N=89 Core or LE Sprain or Strain 135 ° Knee Flexion 1” Heel Elevation

Neurocognitive Reaction TimeSwanik et al. Am J Sports Med. 2007Pre-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 ms Controls: 530 ms11

2011 Neurocognitive Reaction TimeWilkerson GB. Neurocognitive reaction time predicts lower extremity sprains and strains.Int J Athl Ther Train. 2012 .12 Injury No Injury % Injured ≥ 545 ms 18 29 38% < 545 ms 6 27 18% Total 23 52 Fisher’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

Concussion – MSK Injury Incidence 13Herman et al, 2013, Clin J Sports MedCollege athletes with concussion Hx (n=49) vs. matched controls (n=90)LE sprain or strain; Men’s Football + Women’s Basketball, Soccer, & Lacrosse90-day period: 46% of cases injured vs. 17% of controls injured; RR = 2.7Nordström et al, 2014, Br J Sports MedMale 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 ExercRetired NFL football players (n=2429); concussion history prevalence 61%LE MSK injury # - adjustment for years played, BMI (during career), & positionConcussions 1 vs. 0 : OR = 1.6 ; 2 vs. 0 : OR = 2.3 ; 3 vs. 0 : OR = 2.9

Concussion – MSK Injury Incidence 14Lynall 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 AEsCases vs. Controls Pre: 1.78 / 2.56 RR = 0.7Cases vs. Controls Post: 3.51 / 2.14 RR = 1.6Cases Post vs. Pre: 3.51 / 1.78 RR = 2.0

Concussion History Association withCore or Lower Extremity Sprain or Strain15 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 Team N=89 2014 Top 20 FBS Team N=89

16Time-Loss Core or LE Sprain or Strain Risk Factors Injury No Injury Incidence 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 History 2) Concussion History FCS Team N=89

Visual Target Detection Time17Elapsed time (ms) between target button illumination and release of depressed button (non-illuminated)Central focus maintained; central vs. peripheral detection A B C D Central – Right Hand Central – Leftt Hand Peripheral – Right Hand Peripheral – Left Hand

17 Concussion History Cases – 17 Matched Control Players (Football)18Scott AC, Varnell AD University of Tennessee at Chattanooga Graduate Research Project, 2015 Variable Cut-PointSensitivitySpecificity 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

Injury Risk Reduction Strategy19Evidence suggests that both CNS processing and generation of mechanical force can be acceleratedVisual Detection Central Processing Spindle SensitivitySensory Input Integration with Memory = Anticipatory Muscle Activation

Execution of Motor Commands 20Descending driveOutput  α &  MNs Facilitation of excitatory pathways Suppression of inhibitory pathways

Prolonged Effects of Concussion21Persistent alterations in brain function cannot be detected by standard neuropsychological testsChronic subclinical motor system dysfunction Intracortical inhibition of neural transmission (GABAB)De Beaumont et al. 2012, Cereb CortexDe Beaumont et al. 2012, Neurosurg Focus Thériault et al. 2011, J Clin Exp NeuropsycholTremblay et al. 2011, J NeurotraumaDe Beaumont et al. 2007, NeurosurgMcDonell et al. 2006, Exp Brain Res

Inhibition – Neuron Hyperpolarization22 GABA B GABA A

Intracortical Inhibition23Post-concussion elevation of GABA activity believed to be a protective response against glutamate toxicity De Beaumont et al, 2012; Tremblay et al, 2011Subclinical effects may persist for decadesDespite normal neurocognitive test performanceSubtle long-term effects:Stimulus identification and proper response selectionImpairment of visual working memory Slowed reaction timeImpairment of motor learning (decreased neuroplasticity)

Subclinical Effects of Head Impacts24FB players with low visual/sensory performance sustain more severe head impacts (Harpham et al, 2014, Ann Biomed Eng) 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)Current tests insufficiently sensitive to detect subtle changes ( Talvage et al, 2014, J Neurotrauma) Impairments may be more pronounced during multi-task assessment (Lynall et al, 2015, Med Sci Sports Exerc)

Dual-Task Assessment25Imposition of simultaneous cognitive demandImpairment of reaction time, gait, and/or 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

≥ 705 ms Visuomotor Reaction Time 26 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 = 2.9 90% CI: 1.05 – 5.06 * Upper Extremity, Core, or Lower Extremity 2013 N=76

6-Week VMRT Training Program16 120-s sessions (> 50% completion)27 Control: Faster than Baseline Median Value (< 705 ms) 221 ms 134 ms 87 ms 64 ms

Neurocognitive vs. Visuomotor RTCore or Lower Extremity Sprain or Strain28 2014 N=52 Injury No 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 Injury No Injury % Injured ≥ 655 ms 7 4 64% < 655 ms 19 22 46% Total 26 26 Sensitivity = 27 % Specificity = 85% OR = 2.0 90% CI: 0.64 – 6.42

Rapid Multisegmental Response Visual Awareness of Environment Visuomotor Processes Premotor Time Motor Time Neurocognitive Processes Stimulus Detection Stimulus Discrimination Response Selection Task Execution Target Location(s) Cognitive Demand Task Complexity

Psychosocial Stress3014% slower RT + 3.5% reduction in peripheral visionWilliams 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 incidence196 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 ≥ 1439 NCAA Division 1-FCS football players Injury No Injury % Injured ≥ 14 9 10 47% <14 4 16 20% Total 13 26 OR = 3.6 90% CI: 1.10 – 11.84 Henley S University of Tennessee at Chattanooga, Graduate Research Project, 2011

Interrelationships Among Factors Influencing Responsiveness to Environmental Stimuli NEUROCOGNITIVEEXECUTIVEFUNCTION SLEEP QUALITY DIETARY HABITS MENTAL STATUS Life Events Survey for Collegiate Athletes Pittsburgh Sleep Quality Index Healthy Eating Index

Movement Variability (MV)32Accumulating evidence supports MV as an indicator of adaptability to changing demandsPreatoni et al, 2013, Sports BiomechStergious & Decker, 2011, Hum Mov SciPollard et al, 2005, J Appl BiomechVariability traditionally viewed as unexplainable “noise” that inflates measurement “error”Alternate view: Low MV may be an indicator of suboptimal sensorimotor control

Variability: Error vs. Hidden Pattern33 Biological SignalsCyclic Movement Patterns

Low MV – Post-Concussion Balance34Cavanaugh et al, 2006, J Athl TrainMale + Female college athletes with concussion (n=29) Baseline performance vs. 48-96 hours post-concussionLow MV (COP) compared to pre-injury baseline valuesDe Beaumont et al, 2011, J Athl TrainCollege 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)

Inertial Sensor Data – Load VariabilityN=45 17 Weeks (12-Game Season)35 An infinite variety of neuromuscular responses control relative positions of kinetic chain segmentsLow Load Variability (CV ≤ 0.15): OR = 8.2 (OR Adj = 7.8) High Exposure (Plays ≥ 289): OR = 6.4 (ORAdj = 6.1) Low CV ≤ 0.15 High CV > 0.15

NEUROMECHANICAL RESPONSIVENESS TO INJURY POTENTIAL MULTI-SEGMENTAL ALIGNMENT BRAIN PROCESSING OF NEURAL INPUT POSTURAL BALANCE MUSCLE STRENGTH & ENDURANCE VISUOMOTOR REACTION TIME REFLEXIVE MUSCLE RESPONSES

Summary37Risk prediction models are highly specific to cohort characteristics and exact definition of “injury” Core stability and visuomotor reaction time appear to be potentially modifiable injury risk factors Accumulating evidence of long-term impairment of sensorimotor control following concussion Gary-Wilkerson@utc.edu