Balance Ability, Not Muscle Strength and Exercise Endurance, Determines the Performance of Hemiparetic Subjects on the Timed-Sit-to-Stand Test

Abstract

To examine the contribution of balance ability, muscle strength, and exercise endurance to performance in the timed-sit-to-stand test among chronic hemiparetic subjects. A cross-sectional study with 68 community-dwelling stroke survivors. By using Pearson correlation coefficient, the five-times-sit-to-stand (FTSTS) test scores showed the highest negative correlation with Berg Balance Scale scores (r = -0.837, P < 0.001), and it showed significant moderate correlation with muscle strength index (r = -0.577, P < 0.001) and distance covered in a 6-min walk test (r = -0.598, P < 0.001). After controlling for demographic factors, significant partial correlation was identified between FTSTS scores and Berg Balance Scale scores only (r = -0.630, P < 0.001). Linear regression model, after accounting for demographics and subjective balance confidence, showed that FTSTS scores were independently associated with Berg Balance Scale scores (beta = -0.630, P < 0.001), whereas muscle strength index and distance covered in the 6-min walk test were not significant predictors of FTSTS scores. The whole model could explain 71% of the variance in FTSTS scores. This is the first study documenting the importance of balance ability, not muscle strength and exercise endurance, as an important determinant of performance on the FTSTS test by community-dwelling stroke patients. These findings suggest that the FTSTS test may be a more appropriate proxy indicator of balance performance in chronic community-dwelling stroke subjects.