Hip biomechanics differ in responders and non-responders to an ACL injury prevention program

Purpose To investigate the differences in demographic, anthropometric, biomechanical, and/or performance variables between those that do (responders) and do not (non-responders) exhibit reductions in knee abduction moments after an anterior cruciate ligament injury prevention program (ACL-IPP). Methods Forty-three adolescent female athletes completed biomechanical (3D motion analysis of a drop vertical jump) and performance testing before and after randomization into a 6-week ACL-IPP. Participants were classified into responders and non-responders based on their level of reduction of knee abduction moment from pre- to post-test. Results Compared to non-responders, responders exhibited increased hip adduction excursion at baseline ( p = 0.02) and trended towards attending more training sessions ( p = 0.07) and participating in soccer and not basketball ( p = 0.07). Responders also showed greater improvements in hip flexion angles ( p = 0.02) and moments ( p