Comparing the effects of aquatic-based exercise and land-based exercise on balance in older adults: a systematic review and meta-analysis

Balance plays a crucial role in the daily activities of older adults. Aquatic-based exercises (AE) are widely conducted as an alternative to land-based exercises (LE). Previous studies have compared AE and LE as effective ways to improve balance and have yielded inconsistent results. Therefore, this review aimed to compare the effects of AE and LE on balance function in older adults. Electronic databases, including PubMed, Web of Science, Scopus, and Embase, were searched. Randomized controlled trials published from January 2003 to June 2023 were included following predetermined criteria. Data extraction was carried out by two independent reviewers. Data synthesis was conducted using RevMan 5.3 software. The fixed-effect model or random-effect model was chosen based on the results of the heterogeneity test. Meta-analysis for the effect sizes of balance outcomes was calculated as standardized mean difference (SMD) with 95% confidence intervals (CI). The quality of the included studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale. This review was registered at PROSPERO CRD42023429557. A total of 29 studies involving 1486 older adults (with an average age of 66.2 years) were included. Meta-analysis results indicated that AE could improve balance ability based on two tests: the Berg balance scale (BBS: SMD = 1.13, 95% CI 0.25 to 2.00, p = 0.01, I2 = 94%) and the 30-s chair stand test (30 CST: SMD = 2.02, 95% CI 0.50 to 3.54, p = 0.009, I2 = 96%). However, there were no significant differences between the AE group and the LE group in terms of the 6-min walking test (6 MWT: SMD = 0.13, 95% CI -0.16 to 0.43, p = 0.38, I2 = 62%) and time up to go test (TUGT: SMD = 0.44, 95% CI -0.44 to 0.91, p = 0.07, I2 = 85%). Older adults with different health conditions have different gains in different balance measurements after AE intervention and LE intervention. Although this was influenced by participant health status, transfer effects, sample size, and other factors, AE offers better benefits than LE for improving balance function in older adults.