Head injuries due to unrestrained objects during frontal collisions

Abstract

This paper evaluates the consequences of the impact of an unrestrained object against the head of vehicle occupant during a frontal crash by means of a computational head-neck biomechanical model. The correct positioning of head restraints can partially protect the rear side of the head, but there is still a significant probability of being injured. However, because head restraints are typically not properly adjusted as whiplash studies have shown, the probability of being impacted by an unrestrained object during a frontal crash is noticeably high and hence the risk of being injured is also high. In this work, head injury risk is evaluated through the Head Injury Criterion (HIC), by simulating a complete head-neck biomechanical model with realistic motion under frontal crash condition. The model developed includes all cervical vertebrae, intervertebral discs, ligaments and muscles. The model was validated against experimental data. Results have shown that the risk of severe head injury in frontal collision due to unrestrained objects cannot be neglected. The risk is directly related to the mass of the impact object, the relative velocity between the object and the head and the incorrect use of the head restraint.

A concept for mitigating head injury under translational blunt impact

“…Here, t 2 D t o and t 1 is obtained by maximising the quantity within f:::g in Equation (2). It has the solution…”

“…drop tests on cadaver heads) and from re-created real-life impact events in which the injury outcome had been well documented. Such re-creations have been performed both experimentally using instrumented test dummies [2,3,10,36,38] and by computational simulations [2À4, 16,18,29,36,40]. The metrics have found utility in guiding the designs of a wide range of systems for mitigating head injury, ranging from interior cabins of transport vehicles (e.g.…”