Bilateral deficit in explosive force related to sit-to-stand performance in older postmenopausal women

Abstract

The purpose of this study was to determine whether the bilateral deficit (BLD) for maximal voluntary force (MVF) and rate of force development (RFD) influences sit-to-stand in older postmenopausal women. Fourteen women performed unilateral and bilateral maximal voluntary contractions during isometric leg-extension. The MVF and RFD over consecutive 50 ms periods (0–50, 50–100 and 100–150 ms) after force onset and the time to sit-to-stand test were calculated. There was only a BLD for RFD 0–50 ms and 50–100 ms. The time of sit-to-stand was moderately correlated to BLD for RFD 0–50 ms (r = 0.505; 95% CI: −0.035 to 0.817; P = 0.06), but after controlling for physical activity level the relationship was stronger and statistically significant (r = 0.605; 95% CI: 0.109 to 0.859; P = 0.029). These results suggest that the BLD for explosive force (0–50 ms) might represent a performance-limiting factor for sit-to-stand transfer in postmenopausal women and could be dependent of the physical activity level.