Between-Limb Symmetry during Double-Leg Vertical Hop Landing in Males an Average of Two Years after ACL Reconstruction is Highly Correlated with Postoperative Physiotherapy Supervision Duration

Abstract

This study investigates whether double-leg and single-leg vertical hops (VH) landing between-limb symmetry in males, an average of two years after anterior cruciate ligament (ACL) reconstruction (ACLR), is associated with postoperative physiotherapy supervision duration. Thirty-eight healthy controls and thirty-eight males after primary unilateral ACLR, with the use of ipsilateral semitendinosus and gracilis tendon autograft, on average two years before, underwent bilateral peak vertical ground reaction force (vGRF) measurements during double-leg and single-leg VH landing, using two force plates. The vGRF was normalized to the body mass (vGRF BM). The vGRF BM limb symmetry index (LSI) was calculated. Tests for dependent and independent samples and linear Pearson’s correlation coefficient (r) calculations were performed. There were significant between-leg differences in the double-leg (p < 0.001) vGRF BM values. The longer the postoperative physiotherapy supervision duration was, the higher the double-leg VH LSI values (r = 0.727; p < 0.001). There was also a significant but weak positive association between the single-leg VH landing LSI value and the physiotherapy supervision duration (r = 0.333; p = 0.041). Between-limb symmetry during double-leg VH landing in males, an average of two years after ACLR, was correlated with postoperative physiotherapy supervision duration. Fully supervised postoperative physiotherapy for a minimum of six months is more effective for improving VH landing limb symmetry in patients after ACLR.