Association Between Quantitative Gait and Balance Measures and Total Daily Physical Activity in Community-Dwelling Older Adults.

Background: Total daily physical activity is associated with a wide range of adverse health outcomes. We examined the extent to which quantitative measures of gait and balance abilities were associated with total daily physical activity, controlling for a variety of potential covariates.
Methods: Participants (n = 608) were older adults participating in the Rush Memory and Aging Project, a community-based cohort study of aging. Objective measures of total daily physical activity were derived from a wearable device. Gait and balance abilities were objectively quantified using a body-fixed sensor. We also collected measures of other motor functions, cognitive and psychosocial factors, and chronic health. We employed linear regression models to identify facets of mobility significantly associated with total daily physical activity, and tested for independence of these associations when all significant covariates were considered together in a final model.
Results: Three gait and balance measures were independently associated with total daily physical activity (p < .01), together accounting for approximately 16% of its variance. Other motor measures, cognitive and psychosocial factors, and chronic health accounted for 8.8%, 4.9%, and 6.4% of the variance, respectively, when considered in isolation. Considered together in a single model, all significant covariates accounted for approximately 21% of the variance in physical activity. Conclusions: Gait and balance measures from a body-fixed sensor are strongly associated with objectively measured total daily physical activity in older adults. However, given the importance of physical activity to many health outcomes, further work is needed to more completely characterize the factors that may influence physical activity.