Abstract
Introduction We investigated the effect of progressive resistance exercise on knee-muscle strength and joint function in anterior cruciate ligament reconstructed (ACLR) participants with persistent hamstring muscle deficiency, 12–24 months post-surgery.
Materials and Methods A prospective, superiority, randomised controlled trial (RCT) with parallel groups, balanced randomization (1:1) and blinded outcome assessment (level of evidence: II). ACLR (hamstring autograft) participants with persistent hamstring muscle deficiency were recruited, 12–24 months post-surgery, and randomised to either 12-weeks of supervised progressive strength and neuromuscular training (SNG), or home-based low-intensity exercises (CON). Primary outcome was between-group change in maximal isometric knee flexor muscle strength at 12-weeks follow-up. Secondary outcomes included measures of objective strength, MRI and patient reported outcomes.
Results Fifty-one participants (45% women, 27 ± 6 years) were randomized to SNG (n = 25) or CON (n = 26), with data obtained from 88% of participants at 12-weeks follow-up. SNG improved more than CON from baseline to 12 weeks in knee flexor muscle strength (0.18 Nm/kg, 95% CI 0.07 to 0.29; p = 0.002). Furthermore, the SNG group improved in KOOS Pain (4.56, 95% CI 0.43 to 8.69; p = 0.031) and KOOS activity of Daily Living Function (4.71, 95% CI 1.20 to 8.22; p = 0.010) than CON.
Conclusion In ACLR participants with persistent hamstrings muscle deficiency, 12 weeks of supervised progressive strength training was superior compared to low-intensity home based exercises (usual care) for improving knee flexor muscle strength and some patient reported outcomes.