The role of physical activity in mitigating age-related changes in the neuromuscular control of gait.

Exercise induces neural and muscular adaptations, improving muscle mass and function in older adults. We investigated its impact on gait neuromuscular control in young and older adults, classified as more active (young: n = 15, 5185 ± 1471 MET-min/week; old: n = 14, 6481 ± 4846 MET-min/week) or less active (young: n = 14, 1265 ± 965 MET-min/week; old: n = 14, 1473 ± 859 MET-min/week). Isometric maximal voluntary torques were assessed for proximal (knee) and distal (ankle) extensors, and muscle mechanical properties of these muscles were assessed using Myoton. Gait was analysed using ground reaction forces, motion capture, and electromyography. Less active older adults exhibited shorter steps, higher mechanical cost, and greater collision at heel strike. These differences were linked to altered neuromuscular control, wider activation of lumbar and sacral motor pools, different activation timing, and reduced muscle-tendon stiffness. Our findings highlight that physical activity preserves neuromuscular control, muscle mechanical properties, and gait efficiency, mitigating age-related decline.