Changes to Muscle S Tructure in S Eniors May Lead to Deterioration in Contractile Performance

INTRODUCTION Muscle performance depends on the geometrical arrangement of fascicles and contribution of connective tissue both external and internal to the muscle belly. During concentric contractions the muscle belly shortens, the pennation angle increases and the belly thickness changes as a muscle produces force and power. As we age, the muscle structural parameters change [1] and this may contribute to the reduction in strength and consequent loss of mobility and quality of life. Thus, the primary goal of this study was to perform a detailed muscle structural (fascicle length, pennation angle, belly thickenss and belly gearing) and functional (ankle torque and power) comparison between young adults and seniors to determine the differences in muscle structure and links to possible causes of deterioration in performance with ageing. The ankle plantarflexors, Medial Gastrocnemius (MG) and Lateral Gastrocnemius (LG) were tested for this study as these perform d ifferently from each other.