Medial Hamstrings Used as Autograft for ACL Reconstruction Show an Abnormal Neuromuscular Pattern at the Time of Return to Sport

The grafted medial HS showed consistently faster sEMG time-to-peak in the ACLR group than in the control group at all tested velocities. No differences emerged on sEMG amplitude for the medial HS and on both sEMG amplitude and timing for the lateral HS. Those who underwent HS-grafted ACLR showed a higher neuromuscular demand on the grafted medial HS at RTS. This altered overall HS muscle coordination could affect lower limb biomechanics during active movements, potentially increasing the risk of ACL reinjury.