Muscle Force and Range of Motion as Predictors of Function in Older Adults

Musculoskeletal impairments and functional limitations are linked to disability in older adults. The purposes of this study were to identify the extremity musculoskeletal impairments that best predict functional limitations in older adults and to assess the validity of measurements obtained for the Physical Performance Test (PPT) as a predictor of disability. Eighty-one older adults residing in independent and dependent care facilities were tested for extremity muscle force, range of motion, and function. Data were analyzed using multiple regression analysis to identify extremity impairments that predicted function scores and logistic regression analysis to determine whether PPT scores predicted subjects' living situation as dependent versus independent. Subject age, lower-extremity muscle force, and lower-extremity range of motion explained 77% of the variance in function as measured by the PPT. Results differed when analysis was done by subject living situation, with a higher percentage of the variance in function scores explained by musculoskeletal measures for the dependent living group as compared with the independent living group. Extremity musculoskeletal impairments have a strong relationship to function, especially in older adults living in dependent care settings. The results of this study can be used to design interventions to address the musculoskeletal disorders most related to function in the older population.