MUSCULOSKELETAL AND BIOMECHANICS PERFORMANCE IN HUMAN MOTION: EFFECTS OF AGE, SPEED AND DEPTH

Abstract

Speed and depth are essential in assessing and predicting health deterioration. However, quantifications of these conditions are often inconsistent due to different methodologies. In particular, speed-related walking assessments are often experimented on the treadmill instead of over-ground. Moreover, the effect of advancing age in mobility has not been fully elucidated. Hence, this study focuses on the speed and depth effects in over-ground forward (FW) and backward (BW) walking, and squatting among the recreational-active young and elderly individuals. Altering speeds necessitate varying efforts from the hip and ankle during FW and BW, and hip and knee during squatting. Faster speed adapts more slow-twitching fibers, and vice versa. Speed increment elevates the muscle force, which is affected by muscle velocity. Deeper squat enhances slow-twitching fiber adaptation. Elderly is found to employ a distal-to-proximal strategy in FW but not in BW. More fast-twitching fibers are adapted during slower movement among the elderly.