Finite element modeling of the muscle effects on kinematic responses of head-neck complex in frontal impact at high speed

In the present study, a previously developed finite-element model of the ne ck was modified by adding the hill-type muscle elements. The modified model was utilized to investigate the muscle effects un the kinematic responses of the head neck complex in a frontal impact at a speed of around 60 km/h. The behavior of this model was consistent with the literature data describi ng kinematic responses of volunteers and cadavers subjected to such an impa ct. The present results suggest the following : 1) It is likely that, when the neck muscles are activated at around 25 50 ms after the start of the im pact acceleration, they can significantly reduce the peak values of the hea d-gravity center displacements and angular acceleration in a high-speed fro ntal impact; and 2) When the activation of neck muscles starts at around 10 0 ms or later, their effects can be disregarded.