Mass-spring-damper modelling of the human body to study running and hopping--an overview.

Several mass-spring-damper models have been developed to study the response of the human body to the collision with the ground during hopping, trotting, or running. The mass, spring, and damper elements represent the masses, stiffness properties, and damping properties of hard and soft tissues. The masses that models are composed of are connected to each other via springs and dampers. The present paper reviews the various types of mass-spring-damper models including one-body and multi-body models. The models are further categorized as being either passive or active. In passive models, the mechanical properties (stiffness and damping) of soft tissues remain constant regardless of the type of footwear, ground stiffness, etc. In active models, the mechanical properties adapt to external loads. The governing equations of motion of all models as well as their parameters are presented. The specific ways that the models take account of the shoe-ground interactions are discussed as well. The methods used for determination of different modelling parameters are briefly surveyed. The advantages and disadvantages of the different types of mass-spring-damper models are also discussed. The paper concludes with a brief discussion of possible future research trends in the area of mass-spring-damper modelling.