Can We Prevent ACL
Injuries?
Texas Girls Coaches Association
2011 Summer Clinic
Randy Brewer MS, PES, CES
rbrewer413@hotmail.com
817-368-3578
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One Mother’s Perspective
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Our Situation?
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Female athletes are injuring knees at an alarming
rate.
We have been aware of the ACL issue for close
to 20 years but have yet to make a big dent in the
injury rate.
Lack of “coach friendly” assessment tools in the
field that could be used to potentially identify “at
risk” athletes.
Haven’t implemented a wide scale program for
training female athletes to reduce ACL injury rate.
Female Athletes
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As they mature:
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Up to 8 more times likely to tear their ACL’s
Changes during pubertal process negatively effect
neuromuscular control (Hewett et al, JBJS 2004)
Land differently from a jump than boys (Hewlett, et al, JBJS
2004)
Increase quadriceps strength greater than hamstring strength
(Ahmad et al, AJSM 2005)
Exhibit less muscular protection of knee ligaments during
external loading (Wojtys et al, JBJS 2003)
Aggressive quadriceps loading with the knee in slight flexion can
produce significant anterior tibial translation ie. ACL injury! (De
Morat et al, AJSM 2004)
Background
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Musculoskeletal growth during puberty, in the
absence of corresponding neuromuscular
adaptation, may facilitate the development of
certain intrinsic ACL injury risk factors.
Lack of core proprioception and decrease lumbopelvic strength has been implicated as a major
risk factor for the female athlete.
Core stabilization appears to be just as much
about neuromuscular control as it is about
strength.
Up to 80% of ACL injuries are “non-contact” in
nature and many may be preventable.
Why the Concern?
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How does the ACL get
stressed
 Lack of proprioception and
kinesthesia lead to increased
stress on the ACL during
functional loading activities
Non Contact Mechanism
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Mechanism of injury
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Non contact forceful valgus collapse in near
full extension with rotation of the tibia (internal
or external)
Deceleration plant and twist with foot fixed
Higher risk with turf
High risk sports:
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NonContact (80%) vs Contact (20%)
Soccer
Basketball
Football
Etiological Theories
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Anatomical
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Hormonal
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Collagen strength
Joint laxity
Neuromuscular
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Q-angle
Narrow Intercondylar notch
Thigh length
Ligament Dominance
Quadriceps Dominance
Leg Dominance
Trunk Dominance “Core” Dysfunction
Neuromuscular Issues
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Ligament Dominance
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Quadriceps Dominance
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Imbalance between the two legs with respect to
strength, coordination and control (many times from
previous injury)
Trunk Dominance “Core” Dysfunction
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Imbalance between quad and hamstring strength,
recruitment and coordination
Leg Dominance
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Imbalance between neuromuscular and ligamentous
control of dynamic knee stability (lack of shock
absorption)
Imbalance between the inertial demands of the trunk
and control and coordination to resist it.
Knee is “dumb joint” stuck in the middle of the hip
and ankle (“It’s not my fault!)
What does the research say?
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Decrease in Neuromuscular Control with Pubertal
Growth Spurt (Hewett et al, JBJS 2004)
Core Stability Measures as Risk Factors for
Lower Extremity Injury in Athletes (Leetun et al,
MSSE 2004)
Deficits in Neuromuscular Control of the Trunk
Predict Knee Injury Risk (Zazulak et al, AJSM
2007)
The Drop-Jump Video Screening Test: Retention
of Improvement in Neuromuscular Control in
Female Volleyball Players (Barber-Westin et al,
JSCR 2010)
A Training Program to Improve Neuromuscular
Indices in Female High School Volleyball Players
(Noyes et al, JSCR 2011)
What does the research say
about screening?
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Biomechanical Measures Predict ACL Risk in
Female Athletes (Hewett et al, AJSM 2005)
Two Dimensional Analysis Screening and
Evaluation Tool (McLean et al, BJSM 2005)
Correlation Between two-dimensional Video
Analysis and Subjective Assessment in
Evaluating Knee Control Among Elite Female
Team Handball Players (Stensrud et al, BJSM
2010)
Real-Time Assessment and Neuromuscular
Training Feedback Techniques to Prevent
Anterior Cruciate Ligament Injury in Female
Athletes (Myer et al, Strength and Conditioning
Journal 2011)
Three Pronged Approach
to Preventing ACL Injuries
 Injury
Risk Screening
 Intervention
 Dynamic Neuromuscular Training
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Recommendations
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Implement Wide Spread Injury Prevention
Programs for Female Athletes
Focus on ages 12 and up
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Individual Orthopedic and Functional Injury Risk
Assessments
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Identify “at risk” athletes
Injury History Review
Implement injury prevention warm-up
Implement “functional” strength program (inseason and off-season) designed to
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Injury Risk Increases at onset of Puberty
Correct biomechanical dysfunction
Strengthen and improve core function
Improve overall performance and athleticism
Improve neuromuscular control
Recommendations
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Injury History Review (previous injury is a big
predictor of future injury) – Smoke Alarm!!
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Perform Orthopedic and Functional Injury Risk
Assessments
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Performance Enhancement Specialists
Athletic Trainers
Physical Therapists
“Every Nerve and Fiber”
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Low Back Pain
Ankle Sprains
Knee Pain
Unilateral hip pain/discomfort or muscle pulls
When your determination changes, everything will begin
to move in the direction you desire. The moment you
resolve to be victorious, every nerve and fiber in your
being will immediately orient itself toward your success.
 Daisaku Ikeda
Functional Screen
Bi-Lateral Squat technique
 Single leg squat technique
 Balance reach tests
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Lower quarter
Upper quarter
Vertical Drop Jump
 Repeat Tuck Jumps
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Bi-Lateral Squat
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Single Leg Squat
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Vertical Drop Jump
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Tuck Jump Screen
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Orthopedic Screen Intervention
Previous Injuries
 Screen for biomechanical deficiencies
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SI dysfunction
Ankle mobility
Hip mobility
Knee Pain
 Back Pain
 Muscular Injuries
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Training Program
Corrective Soft Tissue Work
 Core Activation
 Core Strength
 Dynamic Warm-Up
 Injury Prevention – Neuromuscular
Control
 Performance Training – Vertical Jump,
Agility, Speed, Explosion
 Strength – Multi-Planar Strength
 Flexibility
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Core Activation - Strength
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Core Activation - Strength
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Core Activation - Strength
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Warm-Up
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Neuromuscular Control
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Neuromuscular Control
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Workout
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The Future
The ACL Prevention Program Must
Correct Poor Functional Movement
Neuromuscular Control
 Dynamic Joint Stabilization
 Rate of Force Production
 Eccentric Strength
 Dynamic Flexibility
 Postural Control
 Previous Injuries
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The Future
The ACL Prevention Program
“Must-Haves”
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Prevention efforts should be included in overall
performance enhancement training program
Prevention efforts should be “user/coach friendly”
and easily implemented in the field
All athletes should complete functional injury risk
assessments
“At Risk” athletes may need medical intervention
followed by corrective exercise program
The Future
Biggest Areas “in the field” That Can
Impact ACL Injury Rates
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Education and Awareness efforts for parents,
athletes, and coaches
Appreciate the significance of previous ankle
sprains, knee and back pain, and muscle injuries
Can’t “power-through” dysfunction
 Piling training on a dysfunctional athlete
creates bigger injury risk
Creating dysfunction with poor training
The Future
Implementation
Train the Trainer
 DVD training program
 Monthly TGCA Newsletter
 E-Learning Options
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