Injury Prevention Ankle Sprains/Anterior Cruciate Ligament Injuries.
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Transcript of 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!
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
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
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