Lower extremity muscle quality and gait variability in older adults

Background: it is not clear if gait variability is linked to muscle strength or muscle quality (MQ). This study examined the relation between leg strength and lower extremity MQ and gait variability in healthy ambulatory 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.