Injury Patterns Among Belted Drivers Protected by Air Bags in 30 to 35 mph Crashes

Abstract

One issue associated with second generation air bags is the concern that the performance in higher severity crashes may be reduced. The purpose of this study is to examine the kinds of injuries sustained by belted drivers in the higher severity crashes, based on cases from the Lehman Injury Research Center at the University of Miami, which conducts interdisciplinary investigations of seriously injured restrained occupants in frontal automobile collisions. The crash severity range examined is the upper limit anticipated by the tests required by the federal standard for air bags and for consumer information: 30 mph (48 kph) and 35 mph (56 kph), respectively. Among 30-mph (48-kph) cases, impacts with narrow objects were overrepresented. The common injury mode for the narrow object impact was liver laceration. These injuries were attributed to the safety belt rather than the air bag. In the higher severity crashes, there were no head injuries. The chest injuries were the most life threatening and included rib fractures and injuries to the liver, spleen, heart, and lungs. Injuries to lower and upper limbs were also present in the higher severity crashes. All cases had liver lacerations. Two different crash conditions may contribute to liver injury: a shoulder belt only, without the lap belt fastened, and a centerline crash with a narrow object at a crash speed around 30 mph (48 kph). In the centerline pole crashes, the belt loading appears to be the initial source of injuries to the liver. It is concluded that the air bag and three-point belt system is providing high levels of protection to belted drivers in car-to-car crashes for the 30-35 mph (48-56 kph) severity range. However, the combined belt and air bag loading may be excessive in some centerline crashes with narrow objects.