Muscle Contraction Is Essential for Tendon Healing and Muscle Function Recovery After Achilles Tendon Rupture and Surgical Repair

This study investigated the role of muscle contraction in tendon healing and muscle function recovery following Achilles tendon rupture and surgical repair using a mouse model. Three postoperative rehabilitation strategies were compared: non-exercise, static stretching, and electrical muscle stimulation (EMS). Tendon mechanical testing, collagen alignment imaging, and muscle histomorphometry revealed that EMS-induced muscle contractions significantly improved early restoration of tendon tensile strength and collagen organization compared to stretching or immobilization. Muscle contraction promoted tendon remodeling without elongation, enhancing both tendon quality and gastrocnemius muscle recovery. The findings highlight that early muscle activation is critical for effective rehabilitation and tendon healing after surgical repair.