Comparative Effects of Home-Based and Aquatic Resistance Training on Hand Tremor Severity and Manual Dexterity in Older Adults with Essential Tremor: A Preliminary Randomized Controlled Trial

Essential tremor (ET) negatively affects neuromuscular control and hand function in older adults. Resistance exercise may enhance musculoskeletal and functional capacity, yet its modality-specific effects in ET remain unclear. This study compared the effects of home-based and aquatic resistance training on tremor severity, manual dexterity, and handgrip strength in older adults with ET. Twenty-seven participants were randomly assigned using block randomization to a home-based resistance exercise group (HBREG; n = 9), an aquatic resistance exercise group (AREG; n = 9), or a control group (CG; n = 9). Both intervention groups completed an 18-session resistance exercise program, with initial sessions supervised and subsequent sessions performed independently under regular monitoring. Tremor severity (FTMTRS), manual dexterity (Nine-Hole Peg Test), and handgrip strength were assessed pre- and post-intervention. Within-group changes were analyzed using the Wilcoxon signed-rank test and between-group differences using the Kruskal-Wallis test with Bonferroni-adjusted Mann-Whitney U tests (p < 0.05). Both HBREG and AREG demonstrated significant improvements in drawing and pouring tremor tasks, manual dexterity, and handgrip strength compared with the control group, with large effect sizes across outcomes. No significant differences were observed between the two exercise modalities, and no improvement occurred in the highest-difficulty spiral-B task. These findings indicate that both home-based and aquatic resistance training are safe and effective non-pharmacological strategies for reducing tremor severity and enhancing upper-extremity function in older adults with ET.