Factors causing abdominal injuries to a vehicle occupant in frontal impact accidents

Abstract

ABSTRACTVehicle occupants were killed in 33% of all fatal traffic accidents in Japan in 2014. The abdomen is associated with the highest risks of serious injuries and fatalities, so we have investigated the causes of abdominal injuries to vehicle occupants. Fifty-four percent of vehicles struck in vehicle-versus-vehicle accidents were impacted from the front. An investigation on accident details determined that lap belts caused serious abdominal injuries. Residual deformation marks suggest that seats move vertically during a frontal impact. The purpose of this study was to clarify the effect of vertical movements of the seat on the lap belt in the event of a frontal impact. We investigated the phenomenon using simulations and an anthropomorphic 50th percentile male Hybrid III dummy model wearing a three-point seat belt. Our results revealed that the lap belt slipped from its initial position around the dummy waist when the seat height was lowered by 150 mm. We concluded that abdominal injuries could be caused by vertical movements in the seat during vehicle-versus-vehicle frontal impacts.