Injury Prevention Ankle Sprains/Anterior Cruciate Ligament Injuries

Ankle inversion sprains >23,000 ankle sprains/day in USA 1 sprain/10,000 people/day Recurrence rates > 70% Females at a 25% greater risk of injury

Epidemiology 23%/25% of all collegiate basketball injuries for women/men 38,000 hs basketball players over 3 years ▪ 38% of girls/36% of boys sustained a foot or ankle injury

Lateral ankle sprains Ankle injuries are the most common sports related injury Reinjury rates as high as 80% Result in time lost from sports and long term disability

Epidemiology Landing most common mechanism Classified as: ▪ Mechanical instability: pathologic ligament laxity ▪ Functional instability: sensation of joint instability due to proprioceptive and neuromuscular deficits

Chronic Ankle Instability (CAI) Repetitive bouts of lateral ankle instability Results in numerous ankle sprains May be due to deficits in ▪ Mechanical stability ▪ Proprioception ▪ Neuromuscular coordination

CAI Functional Instability Proprioceptive deficits ▪ Don’t know where you are in space Impaired neuromuscular firing patterns ▪ Slow reflexes Impaired postural control ▪ Those w/ poor balance had 7x more injuries than those w/ good balance Impaired strength ▪ Insufficient strength to hold good posture

Risk Factors Previous sprain ▪ Mixed findings but may be design differences Sex ▪ 25% higher Grade I sprains in females ▪ No difference in Grade II-III or syndesmosis Postural sway Failure to tape or brace following injury

Acute injury and position sense Passive ankle replication error increased 100% one week post acute inversion sprain No rehab and after 12 wks, a 33% increase in error still existed So get some rehab! The injury is more than what you see!

Focus: ACL injuries

Current Issues Bone bruises and long term outcomes Gender issues Proprioceptive & neuromuscular training Prevention

Gender Issues Increased incidence of ACL injuries in females 4-6x that of male athletes in same sports Most injuries are non-contact

Epidemiology Knee injury rate/1000 exposures ▪ Soccer ▪Men: 1.3 ▪Women: 1.6 ▪ Basketball ▪Men: 0.7 ▪Women: 1.0

Scope & Mechanism of Injury 76 female bktbl injuries in 30 months 72% were knee injuries ▪ ACL 25% of all injuries ▪ 19 in women, 4 in men Mechanism ▪ landing from jump 58% ▪ pivoting 38% ▪ knocked down 4%

Contributing factors Extrinsic ▪ Training & conditioning ▪ Coaching ▪ Position Intrinsic ▪ Anatomy ▪Notch size, Q angle ▪ Physiologic laxity ▪ Hamstring flexibility ▪ Neuromuscular ▪ Biomechanical ▪ Hormonal

Sorting it all out... What is the relationship between.. ▪ Training and conditioning ▪ Coaching ▪ Kinesthesia ▪ Strength ▪ Coordination ??? Neuromuscular control?

Neuromuscular Control Gender differences in motor programming Frontal, sagittal and transverse planes Kinematics and kinetics of landing and cutting

Neuromuscular Control Training neuromuscular control at hip may decrease ACL injuries esp in females

Neuromuscular Control Research consistently finds in females: ▪ Increased LE valgus & hip IR ▪ Decreased hip abduction and ER ▪ Increased quadriceps & decreased hamstring activation

Neuromuscular Control 205 females in high risk sports prospectively studied in jump-land task 9 who subsequently tore their ACL ▪ Knee valgus angle 8x greater ▪ 2.5x greater knee valgus moment ▪ 20% higher ground reaction force ▪ Stance time 16% shorter

Proprioceptive & NM Training Where is the deficit? ▪ Knee joint proprioception ▪ CNS processing ▪ Elasticity of SEC in quadriceps

Predictive value of Results Active proprio positioning predicted knee injury status w/ 90% sensitivity & 56% specificity In female athletes

Neurocognition and ACL injuries n = 80 intercollegiate athletes w/ noncontact ACL injuries & 80 controls Measures ▪ ImPACT neurocog test battery ▪ Post-recon: ACL injured had signif slower reaction time, processing speed and performed worse on visual & verbal memory Diminished capacity for neuromuscular control

Implications for Prevention

Motor Learning Skill learning path ▪ cognitive: requires attention to task, gross strategies developed ▪ associative: gross strategies further developed, increasing efficiency ▪ autonomous: little cognitive processing Goal: get to autonomous level

Motor Learning Cognitive Phase Associative Phase Autonomous Phase What to do How to do it better Just do it

Prevention Proprioceptive ex Neuromuscular retraining Postural exercises Strength training

Postural instability Sway and instability addressed w/ 3 strategies: ▪ Ankle strategy ▪ Hip strategy ▪ Stepping strategy Let’s get up and try this….

Rationale Combination of position sense, kinesthesia, mobility, strength, neuromuscular reeducation “Triple crown” of balance training ▪ Visual ▪ Vestibular ▪ somatosensory

Neuromuscular Retraining Ankle disk training ▪ Improved muscle reaction time Proprioceptive program ▪ Improved joint position sense, postural sway, muscle reaction times Supervised rehab vs. control ▪ No difference at 4 mos. in strength, sway, BUT ▪ 29% reinjury in controls, 7% in training

Ankle disc intervention Same CAI group trained with ankle disk exercises Significant decreases in postural sway Also, 8/15 showed decreased sway in contralateral limb, even though only injured limb was trained

Neuromuscular retraining Single leg stance progression ▪ Visual and cognitive input ▪ Surface adjustments ▪ Reactibility – perturbations ▪ Examples Aerobic training Stepping exercises

What about strength? Ankle strength deficits not highly correlated with CAI But correlated with ACL injury, but only one piece Strength training may also improve proprioception

Functional Training Aerobic conditioning Core stability Running progression Cutting programs Return to sport/work progressions

What does good landing posture look like?

How is this achieved? Same way you get to Carnegie Hall…. Practice!!!!