Plantar flexor muscle size, composition and strength and the redistribution of joint work in gait of healthy older adults

Background

Older adults have altered gait mechanics that may contribute to mobility loss. These changes are suggested to be precipitated by decreased mechanical output from the ankle plantar flexor muscles. However, the extent of age-related changes within individual triceps surae muscles and the consequences for plantar flexor specific torque (torque per unit muscle) and walking mechanics remain unclear. The study aims were (1) to quantify age related differences triceps surae muscle cross-sectional area (CSA), fat fraction and peak absolute and specific plantar flexor torque; (2) quantify differences between younger and older adults in sagittal plane gait kinetics and (3) to examine the relationships between gait kinetics and muscle morphology and function.