Association of Muscle Power With Functional Status in Community-Dwelling Elderly Women

TLDR

Muscle power is increasingly viewed as a key physiologic determinant of functional independence in older adults, potentially more directly linked to performance deficits than muscle strength. The study examined whether peak muscle power predicts self‑reported functional status in sedentary community‑dwelling elderly women, using baseline data from a 1‑year randomized controlled trial of combined strength, power, and endurance training in 80 women with functional impairment or falls. Leg power emerged as the strongest univariate correlate of self‑reported functional status (r = –.47, p < .0001) and, together with habitual physical activity level, explained 40 % of its variance in a stepwise regression model (r = .64, p < .0001).

Abstract

Identification of the physiologic factors most relevant to functional independence in the elderly population is critical for the design of effective interventions. It has been suggested that muscle power may be more directly related to impaired physical performance than muscle strength in elderly persons. We tested the hypothesis that peak muscle power is closely associated with self-reported functional status in sedentary elderly community-dwelling women.We used baseline data that were collected as part of a 1-year randomized controlled clinical trial of a combined program of strength, power, and endurance training in 80 elderly women (mean age 74.8 +/- 5.0 years) with 3.2 +/- 1.9 chronic diseases, selected for baseline functional impairment and/or falls.Functional status at baseline was related in univariate analyses to physiologic capacity, habitual physical activity level, neuropsychological status, and medical diagnoses. Leg power had the strongest univariate correlation 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 factors that contributed independently to functional status (r = .64, p < .0001), accounting for 40% of the variance in functional status.Leg power is a strong predictor of self-reported functional status in elderly women.