Strength-Endurance Training Reduces Tremor Severity and Improves Manual Dexterity and Upper Extremity Function in...

Essential tremor (ET) is among the most prevalent movement disorders, causing significant impairment in manual dexterity and daily functioning. Although ET affects individuals across the lifespan, exercise intervention research has focused almost exclusively on older adults, leaving young adults, for whom early intervention may prevent long-term neuromuscular deterioration, critically underrepresented. Furthermore, the effects of strength-endurance oriented exercise combined with task-specific motor activities remain insufficiently explored in any ET population. This quasi-experimental pre-test-post-test study investigated the effects of a 6-week progressive strength-endurance and task-specific exercise program on tremor severity, manual dexterity, and upper extremity functional performance in young adult males with ET (n = 18; mean age: 22.6 ± 4.1 years). The 24-session intervention (four sessions/week) combined proximal upper extremity strength-endurance exercises with seven ADL-specific fine motor tasks. Tremor severity was assessed using the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS), manual dexterity using the Nine-Hole Peg Test (NHPT), and upper extremity stability using the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST). The Wilcoxon signed-rank test was used for within-group comparisons, with rank biserial correlation (r) and Cohen's d reported as effect size indices. Significant pre-to-post improvements were observed across nearly all outcome measures, with medium-to-large effect sizes. Spiral drawing performance improved significantly in five of six conditions (r = 0.47-0.62), with the exception of the Spiral left-B task (p = 0.083). Postural tremor, NHPT (both hands), and CKCUEST also showed significant improvements (r = 0.47-0.73). A composite tremor score, integrating all tremor sub-scores, demonstrated a 14.1% overall reduction (p = 0.001, r = 0.83), providing strong evidence of program-wide effectiveness. Session adherence was 95.8%. To our knowledge, this is one of the first studies to show that a structured strength-endurance and task-specific exercise program was associated with reductions in tremor severity and improvements in upper extremity function, specifically in young adults with ET. These findings support the clinical utility of exercise as a non-pharmacological intervention in this underserved population and highlight the importance of early, targeted intervention during young adulthood.