Objective: This paper presents a systematic review and meta-analysis of the effectiveness of aquatic exercise for treatment of knee osteoarthritis (OA).
Methods: PubMed, the Cochrane Library, Embase, CAMbase, and the Web of Science were screened through to June 2014. Only randomized controlled trials (RCTs) comparing aquatic exercise with control conditions were included. Two authors independently selected trials for inclusion, assessed the included trials, and extracted data. Outcome measures included pain, physical function, joint stiffness, quality of life (QOL), and safety. Pooled outcomes were analyzed using standardized mean difference (SMD).
Results: There is a lack of high quality studies in this area. Six RCTs (398 participants) were included. There was moderate evidence for a moderate effect on physical function in favor of aquatic exercise immediately after the intervention, but no evidence for pain or QOL when comparing aquatic exercise with nonexercise. Only one trial reported 3 months of follow-up measurements, which demonstrated limited evidence for pain improvement with aquatic exercise and no evidence for QOL or physical function when comparing aquatic exercise with nonexercise. There was limited evidence for pain improvement with land-based exercise and no evidence for QOL or physical function, when comparing aquatic exercise with land-based exercise according to follow-up measurements. No evidence was found for pain, physical function, stiffness, QOL, or mental health with aquatic exercise immediately after the intervention when comparing aquatic exercise with land-based exercise. Two studies reported aquatic exercise was not associated with serious adverse events.
Conclusion: Aquatic exercise appears to have considerable short-term benefits compared with land-based exercise and nonexercise in patients with knee OA. Based on these results, aquatic exercise is effective and safe and can be considered as an adjuvant treatment for patients with knee OA. Studies in this area are still too scarce and too short-term to provide further recommendations on how to apply this therapy.