The association between anthropometric, lower limb strength, and balance variables with 5-repetition sit-to-stand test performance in physically active elderly women

BACKGROUND: Sit-to-stand test is very often used as measure of lower limb strength in elderly adults. However, the recent findings indicate that performance in this test is also influenced by other factors. OBJECTIVE: To investigate the association between anthropometric, lower limb strength, and balance variables with the 5-repetition sit-to-stand test (5RSTST) in elderly women. METHODS: Forty physically active elderly women ⩾ 60 years underwent the 5RSTST and anthropometric, balance, and lower limb strength assessment. Anthropometric measurements included height and weight. Balance was quantified in the bipedal upright stance on the basis of the centre of pressure sway in the anteroposterior (CoPAP) and mediolateral (CoPML) direction. Bilateral concentric strength of the ankle plantarflexors and dorsiflexors, knee flexors and extensors, and hip extensors was measured. RESULTS: The time to complete the 5RSTST was significantly but mildly associated with height (r= 0.356, p= 0.024), ankle dorsiflexor strength (r=-0.413, p= 0.017), knee flexor strength (r=-0377, p= 0.030), knee extensor strength (r=-0.411, p= 0.017), hip flexor strength (r=-0.359, p= 0.040) on dominant limb, and balance in both directions (AP, r= 0.651, p< 0.001; ML, r= 0.647, p< 0.001). Balance control in AP direction and knee extensor strength on dominant limb were the only factors that contributed independently to 5RSTST, accounting for 55% of the variance. Balance control in AP direction alone explained 41% of the variance in 5RSTST. CONCLUSIONS: Balance control in AP seems to be the most important factor explaining the 5RSTST performance.