An evaluation of the association between vertical crush and head, neck and spine injury in rollover motor vehicle crashes: NASS-CDS 1997 through 2007

The relationship between roof deformation in motor vehicle rollover crashes and head, neck, and spine injuries remains debated. While industry-sponsored studies often report no causal link, emerging evidence suggests otherwise. Using data from the National Automotive Sampling System – Crashworthiness Data System (NASS-CDS), this study identifies a significant statistical association between roof crush and injury severity. Each 10 cm increase in roof crush correlates with a 44% increase in odds of head, neck, and spine injury (95% CI: 8–91%) and a 64% increase in odds of severe injury as measured by the Head, Neck, and Spine New Injury Severity Score (HNS-NISS) (95% CI: 26–114%). Employing both cross-sectional and case-control designs, findings support the intrusion hypothesis: stronger roof structures that resist compartment intrusion can mitigate these injuries in rollover crashes.