Absolute vs. relative machine strength as predictors of function in older adults

Abstract

This study examined the relationship between absolute and relative (1 repetition maximum/LBM) strength vs. 13 different functional measurements in 143 older adults (mean = 70.28, standard deviation = 7.90 years). Strength for 11 machine lifts was determined using a predicted 1-repetition maximal strength measurement. Zero-order correlation results between absolute and relative strength vs. function measures demonstrated very weak to moderate correlations in the range of 0.02-0.57 and 0.01-0.44, respectively, with the lowest correlations present between strength and balance measures and the highest correlations present between strength and the carrying task (p </= 0.05). Stepwise multiple regression results also confirmed the low predictability of functional tasks using strength measures, with absolute and relative strength measures accounting for only 3-38% and 3-33% of the various functional measures, respectively. This study identified specific strength measurements that contribute to the variance in a functional task but also clearly indicated that strength alone cannot serve as a predictor of function in older adults.