Effect of functional electrical stimulation on maximum joint angles and gait asymmetry in female athletes post-anterior cruciate ligament reconstruction when crossing obstacles

BACKGROUND: Functional electrical stimulation (FES) can effectively stimulate muscle contraction and has shown great potential in improving human motor function. Female athletes post-anterior cruciate ligament reconstruction (post-ACLR) have pervasive bilateral asymmetries. Moreover, asymmetric gait is often considered one of the risk factors for falls. METHODS: Twenty female athletes post-ACLR were divided into the FES group and the control (CON) group to cross different obstacle heights [(30%, 20%, and 10% of the leg length (LL)]. The two-way repeated analysis of variance was employed to examine the effects between groups and heights, as well as Bonferroni post-hoc comparison and an independent samples t-test. RESULTS: The FES group exhibited significantly decreased maximum hip joint angles (P < 0.001–0.001), knee joint angles (P < 0.001–0.008), swing time (P < 0.001–0.048), gait asymmetry (GA; P < 0.001–0.048), stance time GA (P < 0.001–0.029), and swing/stance time GA (P < 0.001) compared to the CON group when crossing obstacles at 30% and 20% LL, Furthermore, the step length was shorter in the FES group when crossing 30% LL obstacles (P < 0.001). CONCLUSIONS: This study indicated that FES intervention effectively reduces bilateral asymmetry in spatiotemporal gait parameters and enhances lower neuromuscular control ability in female athletes with post-ACLR when crossing obstacles at 20% and 30% of LL. TRIAL REGISTRATION: This trial was prospectively registered with the Chinese Clinical Trial Registry (ChiCTR2100053942) on 04/12/2024.