Purpose: The anterior cruciate ligament (ACL) of the knee is not only a mechanical stabilizer but also provides dynamic sensory feedback that acts as a neuromuscular control function. The purpose of this study was to investigate the effect of perturbation training over 8 weeks on return-to-sport (RTS) criteria in female athletes with ACL injuries classified as “Copers.”
Methods: In this quasi-experimental study, 30 female athletes experiencing unilateral ACL rupture (Coper) were allocated to perturbation training (n=15) and a control group (n=15). The intervention group received 8 weeks of perturbation training (3×/week, 60 min), while the control group continued daily activity and did not include any additional training. Outcome measures included maximum isometric strength of hamstrings and quadriceps (handheld dynamometer), three-hop performance tests (side hop, figure-eight hop, triple hop), and the ACL-return to sport after injury (ACL-RSI) questionnaire. Statistical analyses involved paired t-tests and ANCOVA, and effect sizes (Cohen’s d) were provided.
Results: The perturbation group displayed significant increases in quadriceps strength (mean change: +4.5 Nm, P=0.003, d=0.78), hamstring strength (+10.0 Nm, P=0.001, d=1.02), and hamstring-to-quadriceps ratio (+23%). There were significant improvements in hop performance: side hop (−5.89 s, P=0.002, d=1.65), figure-eight hop (−6.86 s, P=0.005), and triple hop (+117.92 cm, P=0.001). The ACL-RSI score increased significantly by 27% in the perturbation group (P=0.001, d=0.93).
Conclusion: The strength factors of the hamstring and quadriceps muscles and the ratio between these two muscles were enhanced, as well as the functional test results of these athletes. Thus, perturbation training improves RTS criteria in female ACL Copers, improving neuromuscular performance and reducing the fear of reinjury.
Type of Study:
Research |
Subject:
General Received: 2025/03/8 | Accepted: 2025/08/19 | Published: 2026/06/23