Purpose
Anterior cruciate ligament (ACL) tear greatly increases the risk of osteoarthritis, a leading cause of chronic pain and disability. At 2 years post ACLR, altered knee mechanics have been associated with structural changes and longitudinal patient-reported outcomes (PROs). Specifically, increased knee adduction moment (KAM) correlated with cartilage deep tissue matrix degeneration, and greater KAM and flexion moment (KFM) predicted worse PROs in 8 years. In-person laboratory based active feedback gait retraining to produce medial weight shift under the foot has been shown to reduce KAM without increasing KFM in healthy and osteoarthritic knees. This intervention has not been tested in ACLR knees. Recent advancements in wearable technologies render active feedback gait retraining feasible in natural environments. It is unknown whether in-person and remote gait retraining would have similar effects on the KAM and KFM. Thus, this study tested the hypotheses that (1) changes of KAM and KFM after in-person and remote active feedback gait retraining would not differ and that (2) the KAM would reduce without altering the KFM before and after 8 weeks of active feedback gait retraining.