Document Type



We aimed to determine the influence of triceps surae (TS) muscle strength and Achilles tendon (AT) stiffness on age-related changes in locomotor performance and motor task execution strategy during a drop jump (DJ) task. After matching 12 young and 12 middleaged adults for TS muscle strength and AT stiffness, all subjects performed a series of DJs from different starting heights. Matched young and middle-aged adults showed similar DJ performance but the middle-aged adults showed significantly longer ground contact times, lower values in maximum vertical ground reaction force during the support phase and lower mechanical power, independent of starting height. These results suggest that leg extensor muscle strength and tendon stiffness are the primary drivers of age-related changes in locomotor performance, but not motor task execution strategy selection during jumping.