ACL Injury Prevention Programs

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ACL Injury Prevention Programs

• Al T. Douex, Jr., MS, ATC
• Medical Aspects of Sports Conference
• University of Delaware
• 02/25/06

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Anatomy

• Anterior Cruciate Ligament
• Originates at posteromedial corner of lateral
  femoral condyle
• Inserts at anterolateral aspect of tibial spine
• Functions
• Prevents anterior translation of tibia on the
  femur
• Prevents hyperextension
• Secondary stabilizer to valgus and rotational
  stress

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Mechanisms of Injury

• Common MOIs
• Slight knee flexion w/ tibial EROT/IROT at foot
  strike
• Excessive valgus, varus, hyperextension or
  rotation
• Guillotine
• Quads active

• Skiing
• Phantom Foot
• Knee Hyperextension in ski boot
• Valgus rotation
• Other Sports
• Sudden Deceleration
• Abrupt change of direction (fixed foot)
• Single leg landing

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Background

4 7x increased risk for ACL injury
500 900 increased female participation in
sports
Overall increased incidence of ACL injuries
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Healthcare Implications

• In U.S., estimated 38,000 Female ACL
  injuries/year (athletics)
• 200,000 ACL injuries/yr.
• 75,000 total ACL Reconstructions/yr.
• Estimated cost of 17K each
• Increased risk for OA

http//www.youcanbefit.com/ACL.html
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Intervention Programs Do Work!!!
Hewett et al. 1999
Mandalbaum et al. 2005
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Hewett et al. (2005)

• there appear to be 3 major etiological
  contributions to the gender disparity observed in
  ACL injury rates, namely, anatomical (in essence
  nonmodifiable by nature), hormonal (extent to
  which these can be modified remain unclear), and
  neuromuscular.
• Specifically, dynamic joint stabilization is
  achieved via a combination of active muscle force
  and passive ligament restraints.

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Training Perspectives

• Prophylactic training
• Comprehensive neuromuscular training
• ID at-risk athletes
• Sport/Position
• Age/Developmental stage
• Potentially dangerous maneuvers
• Address specific deficits
• Weakness
• Technique
• Endurance
• Neuromuscular Imbalances

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Neuromuscular Imbalances

• 3 typical traits in females
• Ligament Dominance
• Athlete allows ligaments to absorb GRF
• Quadriceps Dominance
• Athlete preferentially increases knee extensor
  moments
• Leg Dominance
• Athlete demonstrates side-to-side differences in
  lower extremity measures

http//www.udel.edu/sportsinfo/womens_basketball
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Neuromuscular Components
http//accelerationclinic.tripod.com/foursquare.jp
g

• Strength Training
• Resistance
• Plyometrics
• Proprioception
• Sport Specific
• Dynamic Training
• Education

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Address Landing Phenomenon
Hewett et al. 2002
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Strength Training

• Appropriate functional ratio between quadriceps
  and hamstrings
• Co-contraction, coordination timing
• Knee dynamic stabilizers
• Strength to control load vs. GRF
• ? peak landing forces, valgus/varus torques
• Incorporate plyometrics

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Proprioceptive Training

• ACL plays a significant role in normal
  proprioception of the knee
• Uninjured females inherently more stable than
  males injured/reconstructed females less stable
  and recover slower (SLS)
• Learn to control loads in coronal plane
• Develop dynamic balance

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Proprioception - Athletic Position
Myer et al. 2004
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Proprioceptive Training
Soderman et al. 2000
Myer et al. 2004
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Sport-Specific Training

• Train Jump/Cut landings
• Control for Dynamic Valgus
• Land using a more bent-knee position
• Train deceleration
• Incorporate speed and agility drills
• ? muscle dominance, ? ligament dominance

Hewett et al. 2005
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Wall Jumps
Myer et al. 2004
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Tuck Jumps
Myer et al. 2004
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Broad Jump Single Leg Hop Hold
Myer et al. 2004
Myer et al. 2004
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180 Jump
Myer et al. 2004
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Squat Jumps
Myer et al. 2004
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X Hops - Bounding
Myer et al. 2004
Myer et al. 2004
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Jump, Jump, Jump, Vertical Jump
Myer et al. 2004
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Education

• Emphasize awareness of dangerous positions,
  MOIs, etc.
• Vermont Ski Instructors
• Feedback/critical analysis of technique
• Partner training

http//www.skivermont.com/
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Continue to Emphasize Technique

• For jumps/cuts, 4 basic techniques should be
  stressed
• Correct posture throughout jump
• Alignment and distribution
• No excessive side-to-side or A/P movement
• Soft landings
• Toe-Heel rocking, knees bent, etc.
• Instant recoil
• Preparation for next jump

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Take Home

• We need to train athletes in such a way that they
  develop feed-forward mechanisms designed to
  protect them when presented with a
  biomechanically dangerous and disadvantageous
  position
• Sell Performance Enhancement (not just Injury
  Prevention)

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Thank You - Questions

• For more information on specific protocols, refer
  to
• Cincinnati Childrens Hospital, Sports Medicine
  Biodynamics Center and Human Performance
  Laboratory (Cincinnati, OH)
• Santa Monica Orthopaedic and Sports Medicine
  Research Foundation (Santa Monica, CA)
• adouex_at_udel.edu

http//www.onlineathens.com/images/120300/women_ca
n_dunk.jpg