The effects on pain, physical function, and quality of life of quadriceps strengthening exercises combined with Baduanjin qigong in older adults with knee osteoarthritis: a quasi-experimental study

BACKGROUND: Exercise is recommended as a principal treatment for individuals with knee osteoarthritis (KOA). However, the best choice for an optimal exercise program able to promote long-term compliance in KOA patients is not clear. This study aims to compare the effect of combined exercise (CE: quadriceps strengthening exercises (QSE) and Baduanjin qigong training (BDJ)) versus QSE alone and BDJ alone on older adults with KOA. METHODS: A three-arm, quasi-experimental trial with repeated measurements was used. As a cluster randomized trial, participants from three community centers were assigned respectively to QSE group, BDJ group and CE group. We assessed pain intensity, physical function, self-efficacy, and health-related quality-of-life (HRQoL) using standardized instruments at baseline, 3 months and 6 months follow-up. RESULTS: One hundred and twenty-eight participants with KOA aged over 60 completed the study. Over the 6 months, there were significant group interaction effects on pain intensity (F = 28.888, P < 0.001), physical function (F = 26.646, P < 0.001), and self-efficacy (F = 22.359, P < 0.001), and, based on a short form-12 item health survey questionnaire (SF-12), physical component summary (F = 7.470, P < 0.001), and mental component summary (F = 10.207, P < 0.001). Overall, the CE group exhibited significantly greater improvement in all outcomes when compared to the QSE group and the BDJ group. CONCLUSIONS: CE treatment is more effective than QSE and BDJ in pain relief, increasing physical function, improving self-efficacy, and raising quality-of-life in community-dwelling KOA older adults. Moreover, it promotes long-term compliance in KOA community patients. TRIAL REGISTRATION: Chinese Clinical Trails Registry number ChiCTR2000033387 (retrospectively registered). Registered 30 May 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-021-04179-8.