ACL Prevention ACL Prevention Neuromuscular Enhancement Russ Paine, PT ISMI Memorial Hermann Hospital Houston, Texas Much interest recent years Identification of possible factors Testing to demonstrate factors Exercise progression/mechanics Program implementation Big question is: ability to follow through to actual sports participation 70%-84% Boden 2000 Orthopedics. Noyes 83 Non-Contact ACL Theories and Proposed Action Neuromuscular control (time to peak T) Lower in female HS. Wojtys AJSM, Meyer Increased valgus & decreased flexion during landing Hewitt AJSM 2005 Axial compressive loading at 25 degrees posterior tibial slope Wall AJSM 2012, Meyer cl.biomech 2009 Foot position during landing (cone of stability, decreased pf) Ireland 99 JATA, Quad domination female HS/Q% weaker in ACL tear females compared to control of both sexes Meyer ClinSportsmed 09 Weakness of LE/core/hips ACL Tears Landing Goal: 60% HS/Q Ratio Over active quad = possible active anterior tibial Altered foot position, outside core/body control Occurs near full extension (5-20 degrees) Olsen AJSM 2004 Training: core/hip/le strength and NM Plyometric positioning 70 Milliseconds to tear ACL 1
Closed chain reduced anterior Closed chain does very little for rotational forces about the knee Markolf 95 Knee Angle During ACL Tear Minimizes Posterior Shear Component of Hamstring Contractile Force Less Able To Offset Anterior Shear Forces Hamstring Resultant Vector Increased Flexion Maximizes Posterior Shear Component of Hamstring Contractile Force More Efficient in Offsetting Anterior Shear Forces Quad F near full extension More compressive than anterior Torzilli AJSM 94 Compressive force anterior force vector near full extension Meyer 2009 could produce ACL tear Posterior tibial slope land less pf θ Ireland JATA 1999 Tennis serve position Mimics landing ACL tear position Greatest ACL strain is with IR Markolf 95 JOrth res, Possible increased notch impingement with ER & Valgus Fung Clin Biom 2003 Position of no Return ACL and Valgus/Abduction Combined ACL/MCL injuries expected with valgus loading theory BUT concomitant ACL/MCL injuries only 4%-17% of total ACL injuries Kaeding Arthosc. 2005 Pivot shift during ACL tear MCL? 2
Does valgus occur after ACL injury? Pivot shifting occurs during ACL tear primarily anterior tibial followed by valgus moment at knee Valgus and ACL Tears ACL consequences DJD Stabilization = Good Evolution DJD = Not Good Yet OA rate 10-20 years after ACL = 50% Lohmander AJSM 2007 Prevention! OA and ACL Dale Daniel AJSM 94 Fate of the ACL Injured Patient Greatest impact MD of his time 55 y/o Daniel AJSM 1994 O Donoghue Award 1993 Honest Researcher Greater DJD in ACL reconstructed knees vs active ACL deficient >injury? vs conservative ACL Joint injury surgery Stress deprivation (immobilization) Prolonged inflammation following surgery Abnormal jt. Mechanics after surgery 3.5 x Basketball 2.8x more prevalent in soccer Based on NCAA ISS (injury surveillanc e system) Female Collegiate ACL Female ACL Military Gwinn 2000 AJSM Military US Naval Academy 1.40 Intramural (soccer, b.ball, softball, v. ball) 3.96 Intercollegiate (soccer, b.ball, s.ball, v. ball) 9.74 Military training (unfamiliar?) SL Squat Trunk Control Test Prone Plank Step down test Figure of 8 run Drop Jump Strength LE/hip Assessment 3
Drop Vertical Jump KAM knee abduction moment Observe Valgus Meyer, Hewitt BJSM 2010,Hewitt AJSM 2005 Testing ACL at risk Target high risk individuals DiStefino 2009, Meyer 2007, Hewett 2005 Respond best to training Land in valgus, knee extension, poor body control Evaluation of ACL Risk Factors Petushek AJSM 2015 ACL Risk Estimation Quiz visual observation to identify at risk athletes Video jump drop test More focused carve-out for prevention 108 trained to prevent 1 ACL Female: hip adduction, femoral internal rotation, tibial external rotation, lumbar lordosis, anterior pelvic rotation Single Leg Squat Male versus Female Effectiveness of Training Programs Noyes 2014 Arthroscopy 42 programs only 2 were effective PEP (prevention and enhance performance program) and Sportsmetrics Compliance big factor 4
Identify individuals with risk factors through evaluation (drop jump test) No substitute for normal strength Include in ACL rehabilitation end stage Conclusions 5