Abstract
BACKGROUND: The demand for anterior cruciate ligament (ACL) reconstruction is steadily rising, necessitating a comprehensive post-ACL rehabilitation plan to accelerate recovery. This study explores the comparative effects of Open Kinetic Chain (OKC), Closed Kinetic Chain (CKC), and their combined effect at a specific knee angle (60° to 90°) in post-ACL reconstruction patients. METHODOLOGY: This clinical trial was registered in the Iranian Registry of Clinical Trials (IRCT) on 21-04-2020 (Ref# IRCT20200331046903N1) and conducted on 54 post-ACL reconstruction patients, randomly allocated to three groups (OKC, CKC, and Combined KC) using the lottery method. All groups underwent 16-week rehabilitation programs. Outcomes assessed were pain, range of motion (ROM), and knee function using the visual analog scale, goniometer, and Lysholm score, respectively. Statistical analysis was conducted using one-way and repeated measures ANOVA in SPSS-25. RESULTS: The mean age was 27.25±4.16 years and BMI 25.12±4.03 kg/m². All groups showed statistically significant improvement over 16 weeks (p<0.0001). At week 16, mean pain scores were 10.56±4.38 (Group A), 9.78±3.81 (Group B), and 3.28±3.12 (Group C) (p<0.001); ROM improved to 131.83±7.35, 129.22±7.57, and 140.61±6.13, respectively (p=0.001); knee function scores reached 90.78±4.83, 91.67±4.49, and 97.50±2.15, respectively (p=0.001). All outcome measures showed significant main effects of Group and Visit, with large effect sizes and significant Group×Visit interactions. From baseline to week 16, pain decreased by 85% (Group A), 86% (Group B), and 95% (Group C); ROM increased by 73%, 72%, and 90%; knee function improved by 58%, 63%, and 72%, respectively. CONCLUSION: These findings indicate that the combined kinetic chain approach is most effective in improving ROM, knee function, and pain reduction following ACL reconstruction. TRIAL REGISTRATION: https://irct.behdasht.gov.ir/.