Injury PreventionAnkle 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!!!!