Head Injuries to Restrained Occupants in Single-Vehicle Pure Rollover Crashes

Abstract

Objective: Studies performed previously of seat-belted occupants in real-world passenger vehicle rollover-only crashes have identified the head as one of the body regions most often seriously injured. However, there have been few studies investigating how these head injuries occur in any detail. This study aims to investigate the characteristics and patterns of head injury to seat-belted occupants in real-world rollover-only crashes and to identify possible biomechanical mechanisms responsible for head injury to aid in the development of a dynamic rollover test protocol.

Methods: National Automotive Sampling System–Crashworthiness Data System (NASS-CDS) data were used to generate summary statistics and perform logistic regression analysis of restrained and contained occupants in U.S. pure trip-over rollover crashes. Specific information from selected CDS cases focused on identifying potential mechanisms and patterns of serious head injury and the rollover conditions under which the injury occurred are also presented.

Results: Twenty-one percent of seriously injured occupants in pure trip-over rollovers had a serious head injury. On average, occupants seated on the far side of the rollover sustained serious head injuries more frequently and were more likely to receive injuries to the inboard side of the head than near-side occupants. Serious head injuries appear to be decoupled from serious injuries to other body regions except for a relationship found between basal skull fractures and cervical spine fractures. Serious head injuries were sustained by some occupants who had less than 15 cm of roof crush above their seated position.

Conclusions: Serious brain injuries appear to occur frequently as a result of loading to the periphery of the head from contact with the roof assembly. Two mechanisms of injury for basal skull fractures in rollover crashes were identified. The injury patterns and locations of contact to the head are sensitive to the seated position of the occupant.

Keywords:

• rollover
• brain injury
• injury mechanism
• NASS-CDS
• serious injury

Acknowledgments

The authors thank the Australian federal government's

Australian Research Council for providing funds to carry out this research through the Linkage Projects grants scheme (No. LP110100069). The authors also thank the industry partners for providing funding, namely, the New South Wales state government's Centre for Road Safety at Transport for New South Wales, the Victorian state government's third-party insurer Transport Accident Commission (TAC), the West Australian (WA) state government's Office of Road Safety at Main Roads WA, the mining company BHP Billiton Ltd., and the U.S. Center for Injury Research (CFIR). The assistance of Professor Ken Digges from George Washington University's National Crash Analysis Center (NCAC) and Professor Frank Pintar from the Medical College of Wisconsin for providing some manuscripts and discussions is also gratefully acknowledged.

Supplemental materials are available for this article. Go to the publisher's online edition of Traffic Injury Prevention to view the supplemental file.