By Jordana Bieze Foster
Hip adduction on landing is a significant predictor of anterior cruciate ligament (ACL) injury risk, according to a large prospective study from the University of North Carolina at Chapel Hill, presented in June at the NATA meeting.
As part of the JUMP-ACL (Joint Undertaking to Monitor and Prevent ACL Injury) study, researchers analyzed landing mechanics in 5700 freshman cadets, 113 of whom suffered noncontact ACL injuries in the next four years.
ACL injury was associated with decreased knee valgus, knee internal rotation, hip abduction, and hip external rotation at baseline. Cadets with hip adduction greater than 0° at initial contact had a relative injury risk (RR) of 4.34. Interestingly, that risk was even higher for hip adduction plus knee varus (RR=6.29-27.62) than for hip adduction plus knee valgus (RR=2.97-4.58).
“If you’re hip-adducted with knee valgus, that’s problematic. If you’re hip-adducted with knee varus, that’s really problematic,” said Darin Padua, PhD, ATC, director of the university’s Sports Medicine Research Laboratory, who presented the findings.
Padua DA, Boling MC, Goerger BM, et al. Prospective differences in lower extremity biomechanics between ACL injured and healthy individuals. Presented at the 63rd annual meeting of the National Athletic Trainers Association, St. Louis, MO, June 2012.