Biomechanics laboratory-based prediction algorithm to identify female athletes with high knee loads that increase risk of ACL injury.
OBJECTIVE
Knee abduction moment (KAM) during landing predicts non-contact anterior cruciate ligament (ACL) injury risk with high sensitivity and specificity in female athletes. The purpose of this study was to employ sensitive laboratory (lab-based) tools to determine predictive mechanisms that underlie increased KAM during landing.


METHODS
Female basketball and soccer players (N=744) from a single county public school district were recruited to participate in testing of anthropometrics, maturation, laxity/flexibility, strength and landing biomechanics. Linear regression was used to model KAM, and logistic regression was used to examine high (>25.25 Nm of KAM) versus low KAM as surrogate for ACL injury risk.


RESULTS
The most parsimonious model included independent predictors (β±1 SE) (1) peak knee abduction angle (1.78±0.05; p<0.001), (2) peak knee extensor moment (0.17±0.01; p<0.001), (3) knee flexion range of motion (0.15±0.03; p<0.01), (4) body mass index (BMI) Z-score (-1.67±0.36; p<0.001) and (5) tibia length (-0.50±0.14; p<0.001) and accounted for 78% of the variance in KAM during landing. The logistic regression model that employed these same variables predicted high KAM status with 85% sensitivity and 93% specificity and a C-statistic of 0.96.


CONCLUSIONS
Increased knee abduction angle, quadriceps recruitment, tibia length and BMI with decreased knee flexion account for 80% of the measured variance in KAM during a drop vertical jump.


CONCLUSIONS
Females who demonstrate increased KAM are more responsive and more likely to benefit from neuromuscular training. These findings should significantly enhance the identification of those at increased risk and facilitate neuromuscular training targeted to this important risk factor (high KAM) for ACL injury.
Myer
Gregory D
GD
Cincinnati Children's Hospital Medical Center, and Department of Pediatrics, College of Medicine, University of Cincinnati, 3333 Burnet Avenue, MLC 10001, Cincinnati, OH 45229, USA. greg.myer@cchmc.org
Ford
Kevin R
KR
Khoury
Jane
J
Succop
Paul
P
Hewett
Timothy E
TE
D000293:Adolescent; D000465:Algorithms; D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000517:prevention & control; D001490:Basketball / Q000293:injuries* / Q000502:physiology; D001696:Biomechanical Phenomena; D015992:Body Mass Index; D002648:Child; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D053580:Muscle Strength / Q000502:physiology; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012916:Soccer / Q000293:injuries* / Q000502:physiology