Relationship between impact velocity and injuries in fatal pedestrian-car collisions

The most common type of fatal pedestrian-car collision, i.e. a passenger ca r with a wedge or pontoon shaped front striking an erect adult with this fr ont, was investigated. A reliable calculation of the impact velocity range by a technical expert and a comprehensive autopsy suitable for traffic acci dents were performed in every case. A total of 47 fatalities fan the materi al of this study and the impact velocities varied between Is and 142 km/h. Primary and secondary injuries did not show a relationship to impact veloci ty. The occurrence of four types of indirect injuries revealed a clear rela tionship to impact velocity, i.e. spinal fractures, ruptures of the thoraci c aorta, inguinal skin ruptures and dismemberment of the body. Important pa rameters such as the type of car, impact velocity range and indirect injuri es are listed for each individual case. Because of the Limited number of ca ses, the impact velocity ranges (3-30 km/h) instead of mean values were con sidered. A cautious interpretation of the data can be summarised in the fol lowing conclusions: If there is no spinal fracture, the velocity was below 70 km/h and probably below 50 km/h. Aortic and inguinal skin ruptures are a lways present if the velocity was above 100 km/h but never occur-ed below 5 0-60 km/h. If dismemberment occurs, the velocity was above 90 km/h. Consequ ently, an estimation of the impact velocity from the presence or absence of indirect injuries is possible in pedestrian-car collisions of the type exa mined. However, the selection criteria applied in this study and additional parameters influencing the collision dynamics have to be considered carefu lly.