Predictors of change in walking velocity in older adults

OBJECTIVE: To determine factors that predict change in walking velocity in older people using a multivariate model. DESIGN: Longitudinal observational study. SUBJECTS: A total of 588 persons older than age 60, including subjects residing in a continuing care retirement community (CCRC) (n = 248), and homebound (n = 79) and ambulatory (n = 261) subjects. Mean age at baseline = 77. MEASUREMENT: independent variables included demographics, physician measures of lower-extremity joint impairment and other musculoskeletal and neurological variables, comorbidities derived from physical examination and chart abstract, self-assessed arthritis pain, depression, and anxiety. The major dependent variables were 2- and 4-year decline in walking velocity below a threshold associated with nursing home placement. MAIN RESULTS: From baseline to Year 4, median walking velocity declined from 61.8 to 53.0 m/min, and the proportion of subjects above a threshold value of 11.5 m/min declined from 95.3% to 80.4%. Age, joint impairment, and weakness of quadriceps, measured at baseline, predicted 2-year and 4-year decline in walking velocity. CONCLUSIONS: The findings indicate that joint impairment and quadriceps strength contribute significantly to crossing a clinically significant threshold in walking velocity among older people over time. Future research is needed to determine whether these risk factors can be modified through preventive interventions such as muscle-strengthening exercises and pain medication.