The Chair Sit-To-Stand Test as a Measure of Leg Strength in Older Adult Women

The purpose of this study was to determine the relationship between isokinetic hip, knee, and ankle joint strength and performance on two chair-sit-to-stand (STS) tests (five- chair STS and 30-sec. chair STS test) in older adult women. Forty-seven women ages 60-70, performed both chair STS tests on the same day, and bilateral isokinetic hip extensor, hip flexor, knee extensor, knee flexor, ankle plantar flexor, and ankle dorsiflexor strength testing (60°/sec.) within seven days of chair STS testing. Regression analyses were performed using the average weight-adjusted isokinetic hip, knee and ankle joint strength scores as the independent variables and five-chair STS test and 30-sec. chair STS test scores as the dependent variables. Pearson correlation results indicated a moderate correlation for all symmetrical bilateral leg muscle groups (r=.67-.80, p=.0001), except the ankle dorsiflexors (r=.33, p=.023). Regression analyses using all six leg strength variables explained 48% (p=.0001) of the variance in five-chair STS test scores and 35% (p=.007) of the variance in 30-sec. chair STS scores. Regression results tend to support ankle plantar flexor strength as the leg muscle with the highest predictive value in both chair STS tests, followed by hip flexor and knee extensor strength, indicating the essential role of the ankle plantar flexors, hip flexors, and knee extensors in completing the chair STS maneuver. The R² values of the regression models tested suggest that variables other than hip, knee, and ankle joint strength influenced chair STS test performance in the sample studied.