What Measure of Lower Extremity Muscle Strength Best Explains Walking Independence?

Abstract

This study was conducted to determine if any one strength measure or combination of strength measures provided an explanation of ambulatory independence among 107 acute rehabilitation patients. This was a retrospective, descriptive, and correlational study where ambulatory function was quantified using the Functional Independence Measure (FIM). Lower extremity strength was quantified by sit to stand performance, and knee extension force measured by manual muscle testing and hand held dynamometry. Descriptive, correlational, and multiple regression statistical analysis were used. Correlation coefficients between ambulatory independence and the different strength measures ranged from .414 to .585. Sit to stand had the highest correlation coefficient with ambulatory independence (r=.585). However a combination of sit to stand performance and total knee extension force offered the best explanation of ambulatory independence (r=.617). A combination of functional and instrumental strength testing is therefore indicated in the prediction of ambulatory performance of patients in acute rehabilitation.