Is aquatic exercise more effective than land-based exercise for knee osteoarthritis?

Background: This study aimed to systemically review the effectiveness of aquatic exercise (AQE) compared to land-based exercise (LBE) in treating knee osteoarthritis (OA). Methods: The Medline, Embase, Web of Science, Cochrane Central Register of Controlled Clinical Trials, CINAHL, and psyclNFO databases were comprehensively searched for randomized controlled trials (RCTs) evaluating the effectiveness of AQE and LBE for knee OA from their inception date to September 24, 2018. The risk of bias was examined using the Cochrane Collaboration Tool, and Review Manager 5.3 was used for data collation and analysis. Results: Eight RCTs were included, involving a total of 579 patients. The meta-analysis showed that there was no significant difference between AQE and LBE for pain relief, physical function, and improvement in the quality of life, for both short-and long-term interventions, in patients with knee OA. However, the adherence and satisfaction level for AQE was higher than for LBE. Compared to no intervention, AQE showed a mild effect for elevating activities of daily living (standardized mean difference [SMD]: -0.55, 95% confidence interval [CI] [-0.94, -0.16], P=.005) and a high effect for improving sports and recreational activities (SMD: -1.03, 95% CI [-1.82, -0.25], P=.01). Conclusion: AQE is comparable to LBE for treating knee OA.