Long-Term Knee Joint Loading Alterations in Athletes 5 Years Post-ACL Reconstruction: A Comparative Gait Analysis

Abstract

Anterior cruciate ligament (ACL) reconstruction is widely used to restore knee stability and enable return to sport; however, long-term recovery of normal gait biomechanics remains uncertain. This study investigated projected knee joint loading and gait mechanics five years post-ACL reconstruction across different rehabilitation paradigms using a predictive modeling approach. Four cohorts were analyzed: healthy controls, standard physiotherapy-based rehabilitation, neuromuscular training-based rehabilitation, and advanced feedback-assisted rehabilitation. Results indicate persistent alterations in knee biomechanics in the standard rehabilitation group, characterized by reduced knee flexion moments, elevated loading rates, and increased gait asymmetry. The neuromuscular training group demonstrated partial improvements in temporal coordination and muscle activation patterns, although kinetic normalization remained incomplete. In contrast, the feedback-assisted rehabilitation group exhibited gait patterns closely resembling healthy controls, with near-normal knee loading, improved symmetry, and more physiological neuromuscular timing. Overall, findings suggest that long-term biomechanical recovery following ACL reconstruction is highly dependent on rehabilitation strategy. Conventional rehabilitation alone may be insufficient for full restoration of knee joint loading, whereas integrated feedback-based approaches may offer superior outcomes in achieving durable neuromechanical normalization and reducing long-term risk of degenerative joint changes.