Effectiveness of aquatic exercise in lower limb osteoarthritis: a meta-analysis of randomized controlled trials

The objective of this study was to evaluate the short-term and follow-up effectiveness of aquatic training on the health status of lower limb osteoarthritis. Randomized controlled trials (RCTs) on related topics were systematically searched in PubMed, Embase, Web of Science, the Cochrane Library, Physiotherapy Evidence Database (PEDro), the China National Knowledge Infrastructure and Wanfang databases from inception to January 2021. RevMan 5.3 was used for statistical analysis, and the standardized mean difference (SMD) was used to present pooled effect sizes. As a result, 19 RCTs (1592 patients) were included. Compared with unsupervised home exercise or usual care (land-based training excluded), aquatic training showed short-term pain relief (SMD, -0.54; 95% CI, -0.81 to -0.28), physical function improvement (SMD, -0.64; 95% CI, -1.00 to -0.28), stiffness reduction (SMD, -0.40; 95% CI, -0.79 to -0.01) and improved function in sport and recreation (SMD, -0.30; 95% CI, -0.59 to -0.02). Analyses restricted to patients with knee osteoarthritis only also confirmed the positive effects of aquatic training on most dimensions excluding physical function. At medium-term follow-ups, improvements in physical function and function in sport and recreation were observed. No significant difference was observed between arms in the above four outcomes at long-term follow-ups. All studies reported no major adverse event with relation to aquatic training, and the minor adverse events were not common. It is concluded that aquatic training likely has short-term benefits on pain, physical function, stiffness and sport ability in lower limb osteoarthritis patients, but these positive effects may not last long.