Effects of Dynamic Stability Training with Water Inertia Load on Gait and Biomechanics in Older Women: A Randomized Clinical Trial

Background: Gait decline in older adults is closely linked to reduced ankle propulsion and a compensatory reliance on proximal joints. This randomized trial investigated whether dynamic stability training using water inertia can improve gait mechanics and redistribute lower-limb joint moments in older women. Hypotheses: (1) The training would improve gait speed, stride length, and cadence. (2) The ankle plantar flexor moment and positive mechanical work would increase, while hip extension moment would decrease. Method: Twenty-four women aged 65 years and older were randomly assigned to either an experimental or control group. The experimental group wore a water-filled aquavest, and the control group wore a weighted vest. Both groups performed the same training program twice weekly for 12 weeks. Outcome measures included gait speed, stride length, cadence, ankle plantar flexion moment, hip extension moment, and positive mechanical work during terminal stance. A two-way mixed (between–within) analysis of variance (ANOVA) evaluated the group × time interaction effects. Results: Significant group × time interactions were found for gait speed (p < 0.001), stride length (p < 0.001), ankle moment (p = 0.017), and positive work (p < 0.001). Cadence increased in both groups over time (p < 0.05), with no interaction. The hip moment declined slightly in the experimental group. Conclusions: Water inertia load training enhanced propulsion and promoted an ankle-dominant gait, supporting its use to improve gait function and reduce proximal compensation in older women.