Acute effects of ipsilateral semitendinosus and gracilis autograft anterior cruciate ligament reconstruction on lower limb muscle activation

There is little information regarding the acute repercussions of anterior cruciate ligament (ACL) reconstruction on muscle activation, especially on the proximal hip muscles. Thus, this study analyzed the acute effects of ACL reconstruction with doubled semitendinosus/gracilis (ST/G) autografts on lower limb muscle activation. Fourteen male recreational athletes that presented a primary unilateral ACL rupture and underwent the ACL reconstruction with an ST/G graft. Surface electromyographic (sEMG) signal were recorded from each participant during the maximal voluntary isometric contraction (MVIC) of the gluteus maximus and gluteus medius, vastus lateralis and vastus medialis, semitendinosus, biceps femoris, and medial gastrocnemius muscles and also during bipodal mini-squatting with open and closed eyes, before surgery and 15 days postoperatively. (sEMG) signal were normalized to isometric peak electromyography. The postoperative assessment showed reduced muscle activation in the gluteus maximus (p = 0.013, d:0.48) in non-operated limb and also in the muscle gluteus medius (p = 0.013, d:0.79), vastus medialis (p = 0.035, d:0.63) semitendinosus (p = 0.001, d:2.46), biceps femoris (p