Injury causation scenarios in belt-restrained nearside child occupants.

Successful development of side impact safety systems for rear row child occupants requires an understanding of injury causation and mitigation. However, data to guide the design of such safety systems for seat belt-restrained occupants is limited to injury risk assessments. Thus, we sought to elucidate Injury Causation Scenarios (ICS's) in children restrained by seat belts in nearside impacts. Included in the study were 4 to 15 year old children, involved in a side impact, seated on the nearside in the rear rows, restrained by a seat belt alone (no booster seats or side airbags) and who received an AIS 2+ injury. A Contact Point Map summarized the vehicle components that contribute to the injuries. The majority of head and face contacts points were found horizontally within the rear half of the window, and vertically from the window sill to the center of the window, and were a result of contact with both interior structures and structures on the crash partner. The most prevalent intracranial injuries included cerebral contusions, diffuse axonal injury (DAI), and subdural or subarachnoid hematoma/hemorrhage. The most common cause of torso and abdominal injury was contact with the side interior structure, and injuries included spleen lacerations or ruptures, liver lacerations and contusions, lung contusions, rib fractures, and clavicle fractures. Protuberances on the door interior, such as the armrest, were the most common source of abdominal injury in this dataset. These data provide important guidance for the development of rear row safety systems for belt-restrained children with no side airbags in nearside crashes.