Bridging Preventive Care and Active Ageing: Effects of Home-Based Open and Closed Kinetic Chain Exercise on Functional Performance, Trunk Biomechanics and Quality of Life in Women with Mild Knee Osteoarthritis

Abstract

Background and Objectives: Preventive physiotherapy supports active ageing and reduces knee osteoarthritis burden. Although exercise is recommended, the comparative effects of open kinetic chain (OKC) and closed kinetic chain (CKC) home-based exercise on function, trunk biomechanics and quality of life remain unclear. This study evaluated an eight-week physiotherapist-guided OKC and CKC programme in women with mild knee osteoarthritis. Methods: This single-blind randomized controlled trial recruited 66 women aged ≥50 years in Putrajaya, Malaysia. Participants were randomized into OKC, CKC or education-only control groups. Sample size was calculated using G*Power based on WOMAC function, with effect size 0.50, 90% power and alpha 0.05. Exercise groups performed home exercises three times weekly, guided by an initial physiotherapy session, exercise diary and bi-weekly telephone follow-up. Outcomes were assessed at baseline and post-intervention by a blinded assessor. Trial registration: NCT04678609. Results: Fifty-nine participants completed the study. Compared with education-only control, both exercise groups showed significant improvements in pain, WOMAC physical function, quality of life, walking speed and five-time sit-to-stand performance. Large effects were observed for pain reduction (p<0.001, partial η²=0.658), WOMAC physical function (p<0.001, partial η²=0.454), walking speed (p<0.001, partial η²=0.527) and five-time sit-to-stand performance (p<0.001, partial η²=0.444). Trunk flexion also improved significantly with a moderate effect size (p=0.007, partial η²=0.123). Conclusion: Physiotherapist-guided home-based OKC and CKC exercise improved pain, mobility, biomechanics and quality of life, supporting active ageing in community physiotherapy care