Postmortem evidence on head injuries was used in conjunction with data on vehicle damage and crash circumstances to describe the mechanisms of head injury in a group of 30 fatal car crashes. The experience of a neuropathologist was linked with that of an accident investigator to explore the possibilities for improving understanding of how loading is transmitted through the car structure to the head. The load paths within the head were also traced to provide insight into the mechanism of injury, and to assist in linking injury tolerance work with accident reality. Accident selection was aimed at crash situations similar to those frequently evaluated with dummies. This was a pilot study to explore the possible benefits of this technique.

The sample was structured to contain equal numbers of frontal and side impacts. In the frontal impacts studied, loading to the skull was usually transmitted via the facial bones. In both crash types, basal skull fractures were more common than fractures of the vault. There were differences in the patterns of loading to the head and the injuries suffered in frontal as opposed to side impacts. The loading conditions in both crash types were different from those used to establish the original tolerance curves that underpin the Bead Injury Criterion calculated from dummy accelerations. Improved methods of recording the information from routine postmortem investigations would aid future injury tolerance work.