Hill-type muscle model for analysis of mechanical effect of muscle tensionon the human body response in a car collision using an explicit finite element code

A string of series-connected Hill-type bars is proposed for modeling the ef fect of muscle tension on human body kinematics in a car collision. The pre liminary results indicated that such strings exhibit oscillations and insta bilities when subjected to a large and transient stretch. A new algorithm f or calculation of the force-velocity of the deformation relationship and th e concept of the Hill-type multi-bar muscle element are introduced as count ermeasures against these instabilities. In the Hill-type multi-bar muscle e lement, muscle force is computed from the sum of the deformations and the v elocities of deformation of all the series-connected bars applied to model a given muscle. When the Hill-type multi-bar muscle element was applied to model experiments on fast stretching of an activated muscle, the calculated force well corresponded with the results published in the literature. More over, the current approach to muscle modeling yielded results consistent wi th the literature data on volunteers subjected to transient acceleration wh en it was utilized in simulations of the effect of muscle tension on the he ad-neck kinematics in a frontal car collision.