Stepping into a safer movement: The relationship between foot progression angle and lower extremity biomechanics...

Anterior cruciate ligament injury rates are high and often associated with change-of-direction movements. Analysis of youth movement patterns is critical for avoiding injury and foot progression angle affects lower extremity kinematics during cutting movements. Knee abduction and hip adduction are known predictors of anterior cruciate ligament injury. The relationship between foot progression angle and lower extremity biomechanics lacks exploration in youth athletes following anterior cruciate ligament reconstruction. This study aimed to assess the relationship between foot progression angle at max knee flexion, and mechanics predictive of anterior cruciate ligament injury during a change-of-direction task in youth athletes following anterior cruciate ligament reconstruction.

Thirty-four participants (12 m, 15.0 ± 2.5 years) who previously underwent anterior cruciate ligament reconstruction participated in the study. Participants performed a 45-degree run cut task on both affected and unaffected limbs. Trunk and lower extremity biomechanics were collected using 3D motion capture and force plates.

Moderate correlations were observed on the affected limb for trunk, pelvis, hip, knee, and ankle angles, as well as ankle moments (r = -0.34-0.52). On the unaffected limb, moderate correlations were seen in pelvis, hip, and ankle angles (r = 0.41-0.44). Significant differences exist between limbs for pelvis, hip and knee angles, as well as knee moments (p ≤ 0.038).

Youth athletes appear to exhibit cutting movement patterns following anterior cruciate ligament reconstruction that may increase their risk of anterior cruciate ligament reinjury. Foot progression angle is a potential component of cutting tasks that clinicians and coaches can use to reduce an athlete's injury risk.