The effect of preloads on muscles in the multi-body model for the analysis of whiplash by rear end impact
Jung JE., Han HS., Yang SJ.
Whiplash injury is caused when a neck receives a sudden movement such as rear-end impact by Motor Vehicle Collision (MVC). At the time of impact, hyper-extension and hyper-flexion occurs less than 1 second after the impact, where the head is forcefully thrown backwards while the body is going forwards. Resulting action caused by the whiplash snaps the head violently and causes damages in the soft tissue components of the neck such as disc, muscles and ligaments. The injury in the neck has been considered as a significant public health problem and it is known that about 20% of car accidents results in a whiplash injury. This paper presents a multi-body model of the human neck developed for the study of whiplash motion. The model is composed of a head, each separated vertebra, upper torso body with muscles and ligaments attached in the cervical region. Differing from any other models suggested in the former simulation of the whiplash, our model is specified with some active muscle forces which are determined by optimization with the concept of the follower load. The cognitive and non-cognitive preloads on the muscles at the time of rear-end impact are also evaluated. The dynamic data of the head and the responses of the soft tissues are obtained comparing with preloaded and non-preloaded muscles as well as cognitive and non-cognitive loads. The physiological range of motion of the cervical spine is compared with the angular motion of the model by the impact to see the possible damage of the spine. The responses of the soft tissues are correlated with the damages of the neck in order to show the feasibility of a new multi body model for the whiplash. Copyright (c) 2010 by JSME.