Comparison of muscle function predictions using mass-enhanced and massless Hill-type muscle models in human locomotion

Muscle mass significantly shapes skeletal muscle behavior and might partially clarify why traditional massless Hill-type models struggle to predict larger muscle functions in dynamic, submaximal contractions. However, the applicability of mass-enhanced Hill-type models in human locomotion remains unexplored. In my thesis, I compared predictions of human muscle performance (force, work output) between mass-enhanced and massless Hill-type models across varied scaled muscle sizes, tasks, and locomotion conditions. I observed minor but noteworthy mass effects in human-sized muscles across different tasks and muscles, escalating with scaled muscle mass. These effects were more pronounced at higher cycling cadences, unaffected by crank loads. Additionally, increased muscle mass resulted in a reduction in muscle mechanical work per cycle.