Association of muscle power with functional status in community-dwelling elderly women

Background. Identification of the physiologic factors most relevant to func tional independence in the elderly population is critical for the design of effective interventions. It has been suggested that muscle power may be mo re directly related to impaired physical performance than muscle strength i n elderly persons. We tested the hypothesis that peak muscle power is close ly associated with self-reported functional status in sedentary elderly com munity-dwelling women. Methods. We used baseline data that were collected as part of a I-year rand omized controlled clinical trial of a combined program of strength, power, and endurance training in 80 elderly women (mean age 74.8 +/- 5.0 years) wi th 3.2 +/- 1.9 chronic diseases, selected for baseline functional impairmen t and/or falls. Results. Functional status at baseline was related in univariate analyses t o physiologic capacity, habitual physical activity level, neuropsychologica l status, and medical diagnoses. Leg power had the strongest univariate cor relation to self-reported functional status (r = -.47, p < .0001) of any of the physiologic factors we tested. In a forward stepwise regression model, leg press power and habitual physical activity level were the only two fac tors that contributed independently to functional status (r = .64, p < .000 1), accounting for 40% of the variance in functional status. Conclusions. Leg power is a strong predictor of self-reported functional st atus in elderly women.