RESUMEN
BACKGROUND: More than half of car crash fatalities are belted occupants, and the majority of these occur as a consequence of frontal crashes. In an earlier study of crash configuration characteristics, we have shown that 48% of fatalities occurred in frontal small overlap (SO) crashes in which less than 30% of the vehicle front was engaged. Only 23% of fatalities occurred in large overlap (LO) crashes engaging the drive train, similar to most barrier front crash testing procedures. The main purpose of this study was to analyze the characteristics of injury mechanisms and injuries in fatal SO and LO car crashes in Sweden. METHOD: Retrospective examination and analysis of 61 fatally injured occupants from 53 car crashes within a sample area covering 40% of the population of Sweden was conducted. RESULTS: A clear difference in injury mechanisms and injuries was found between SO and LO crashes. The major injury mechanisms in SO crashes are explained by an oblique torso movement and rotation toward the outboard side, which causes a high proportion of serious lateral chest and head injuries. In contrast, LO crashes were generally characterized by serious anterior chest injuries in elderly occupants (> or =60 years). CONCLUSION: Current government and consumer barrier crash test procedures are not designed to estimate the performance of cars and restraint systems for the type of crashes which caused the majority of occupant fatalities in this data set.