Computational Modelling of Human Gait: Muscle Coordination of Walking and Running

Abstract

Walking is a task that most people perform with ease. Although seemingly simple, it is an extraordinarily complex skill that takes years to develop. The various actions of the leg muscles are exquisitely timed to provide support against gravity, maintain forward progression, and control balance from step to step. Many experiments have been undertaken to better understand the biomechanics of gait, yet little is currently known about the way individual muscles coordinate body movement, primarily because experiments provide very limited information on muscle function. This applies even for walking at the preferred speed, and virtually nothing is known about individual muscle function under other conditions, such as walking and running at different speeds.

Biomechanical computer modelling has risen to new heights in recent years, mainly because of the belief that this approach can yield new insights into how the neuromuscular and musculoskeletal systems interact during daily physical activity. Recent advances in imaging technology, numerical modelling techniques, and computing power have enabled elaborate models of the body to be built for the purpose of studying tissue function in vivo. In this presentation, I review how the structure of the neuromusculoskeletal system is commonly represented in a multi-joint model of movement; how musculoskeletal modelling may be combined with optimization and nonlinear control theory to simulate the dynamics of human gait; and how model output can be analysed to describe and explain leg-muscle function during locomotion.