5-repetition sit-to-stand test in subjects with chronic stroke: reliability and validity.

Abstract

To examine the (1) intrarater, interrater, and test-retest reliability of the 5-repetition sit-to-stand test (5-repetition STS test) scores, (2) correlation of 5-repetition STS test scores with lower-limb muscle strength and balance performance, and (3) cut-off scores among the 3 groups of subjects: the young, the healthy elderly, and subjects with stroke. Cross-sectional study. University-based rehabilitation center. A convenience sample of 36 subjects: 12 subjects with chronic stroke, 12 healthy elderly subjects, and 12 young subjects. Not applicable. 5-Repetition STS test time scores; hand-held dynamometer measurements of hip flexors, and knee flexors and extensors; ankle dorsiflexors and plantarflexors muscle strength; Berg Balance Scale (BBS); and limits of stability (LOS) test using dynamic posturography. Excellent intrarater reliability of intraclass correlation coefficient (ICC) (range, .970-.976), interrater reliability (ICC=.999), and test-retest reliability (ICC range, .989-.999) were found. Five-repetition STS test scores were also found to be significantly associated with the muscle strength of affected and unaffected knee flexors (rho=-.753 to -.830; P<.00556) of the subjects with stroke. No significant associations were found between 5-repetition STS test and BBS and LOS tests in subjects with stroke. Cut-off scores of 12 seconds were found to be discriminatory between healthy elderly and subjects with stroke at a sensitivity of 83% and specificity of 75%. The 5-repetition STS test is a reliable measurement tool that correlates with knee flexors muscle strength but not balance ability in subjects with stroke.