The effect of aquatic therapy on postural balance and muscle strength in stroke survivors - a randomized controlled pilot trial

Objective: To evaluate the effect of an aquatic therapy programme designed to increase balance in stroke survivors. Design: A randomized, controlled pilot trial. Setting: Rehabilitation department of a university hospital. Subjects: Ambulatory chronic stroke patients (n=25):13 in an aquatic therapy group and 12 in a conventional therapy group. Interventions: The aquatic therapy group participated in a programme consisting of Ai Chi and Halliwick methods, which focused on balance and weight-bearing exercises. The conventional therapy group performed gym exercises. In both groups, the interventions occurred for 1 hour, three times per week, for eight weeks. Main measures: The primary outcome measures were Berg Balance Scale score and weight-bearing ability, as measured by vertical ground reaction force during four standing tasks (rising from a chair and weight-shifting forward, backward and laterally). Secondary measures were muscle strength and gait. Results: Compared with the conventional therapy group, the aquatic therapy group attained significant improvements in Berg Balance Scale scores, forward and backward weight-bearing abilities of the affected limbs, and knee flexor strength (P<0.05), with effect sizes of 1.03, 1.14, 0.72 and 1.13 standard deviation units and powers of 75, 81, 70 and 26%, respectively. There were no significant changes in the other measures between the two groups. Conclusions: Postural balance and knee flexor strength were improved after aquatic therapy based on the Halliwick and Ai Chi methods in stroke survivors. Because of limited power and a small population base, further studies with larger sample sizes are required.