Exercise effect on dynamic stability in older women: a randomized controlled trial.

Abstract

OBJECTIVE: To determine whether a 12-month program of regular exercise can improve dynamic postural stability in older women. DESIGN: Randomized controlled trial of 12 months' duration. SETTING: Conducted as part of the Randwick Falls and Fractures Study, in Sydney, Australia. PARTICIPANTS: One hundred and twelve community-dwelling women aged 60 to 85 years (mean age 71.2, SD = 5.4). OUTCOME MEASURES: Quantitative measures of dynamic postural stability: maximal balance range and coordinated stability. MAIN RESULTS: Exercise and control subjects were tested before, midway through, and at the end of the trial. The stability measures had good test-retest reliability, and test performances were significantly associated with measures of lower limb muscle strength, reaction time, neuromuscular control, and body sway. At initial testing, exercisers and controls performed similarly in the two stability measures. The mean number of classes attended for the 48 exercise subjects who completed the program was 58.4 (range 26-77). At the end of the trial, the exercise subjects showed significantly improved performance in both the maximal balance range and coordinated stability tests, with no improvement evident in the controls. Improvements in coordinated stability were associated with corresponding improvements in ankle dorsiflexion, hip extension, and hip flexion strength. CONCLUSION: These findings show that exercise can significantly improve dynamic postural stability in older persons and elucidate some possible mechanisms by which such improvements may be mediated.