Lower extremity muscle quality and gait variability in older adults

Methods: seventy-two older adults (43 females and 29 males; age: 69.5 +/- 6.1 years) underwent assessments of gait, leg strength and body composition. Leg strength was assessed with an isokinetic dynamometer and body composition by dual-energy X-ray absorptiometry (DXA). MQ was calculated from the information muscle strength and body composition. Gait was assessed by having the subjects walk down a pressure sensitive walkway at self-selected normal speed. Variability of spatial and temporal parameters of gait was calculated. Results: there were minimal correlations between muscle strength and spatial parameters. However, both lower leg and upper leg MQ were negatively associated with spatial (r's = -0.24 to -0.49, P < 0.05) and temporal gait variability (r's = -0.27 to -0.35, P < 0.05). Also, lower leg MQ was found to be a better predictor of gait variability than upper leg MQ. Conclusions: the results highlight that MQ may be an important determinant of gait function, even in healthy older adults.