The impact of body composition, pain and resilience on physical activity, physical function and physical performance at 2 months post hip fracture.

The purpose of this study was to test a model of the factors influencing physical activity, physical function and physical performance at 2 months post hip fracture and compare model fit between men and women. Age, cognitive status, comorbidities, pain, resilience, bone mineral density, total body lean mass, total body fat and grip strength were hypothesized to be directly and/or indirectly related to physical activity, physical function and physical performance. This analysis used data from the seventh Baltimore Hip Studies (BHS-7), a prospective cohort study that included 258 community-dwelling participants, 125 (48%) men and 133 (52%) women, hospitalized for treatment of a hip fracture; survey and objective data were obtained at 2 months post hip fracture. In addition to age, sex and comorbidities (modified Charlson scale), data collection included body composition from dual-energy x-ray absorptiometry (DXA) scans, grip strength, and physical activity, function and performance based on the Yale Physical Activity Survey, the Short Physical Performance Battery and the Lower Extremity Gain Scale. Age, cognition, and comorbidities were not significantly associated with resilience; and, resilience was not associated with pain. In addition, bone mineral density was not associated with physical activity, physical performance or physical function. Total lean body mass, resilience and pain were associated with physical activity, physical function and physical performance in women, but were not consistently associated with physical and functional outcomes in men. Future research should consider evaluation of muscle quality and additional psychosocial factors (e.g., depression, social supports) in model testing.