The relationship of body mass index, belt placement, and abdominopelvic injuries in motor vehicle crashes: A Crash Injury Research and Engineering Network (CIREN) study

Objective: Obesity has important implications for motor vehicle safety due to altered crash injury responses from increased mass and improper seatbelt placement. Abdominal seatbelt signs (ASBS) above the anterior superior iliac spine (ASIS) in motor vehicle crashes (MVCs) often correlate with abdominopelvic trauma. We investigated the relationship of body mass index (BMI), lap belt placement, and the incidence of abdominopelvic injury using computed tomography (CT) evaluation for subcutaneous ASBS mark and its location relative to the ASIS. Methods: A retrospective analysis of 235 Crash Injury Research and Engineering Network (CIREN) cases and their associated abdominal injuries was conducted. CT Scans were analyzed to visualize fat stranding. 150 positive ASBS were found and their ASBS mark location was classified as superior, on, or inferior to the ASIS. Results: Obese occupants had a higher incidence rate of belt placement superior to the ASIS, and occupants with normal BMI had a higher incidence of proper belt placement (p < 0.05). Trends of interest developed, notably that non-obese occupants with superior belt placement had increased incidence of internal abdominopelvic organ injury compared to those with proper belt placement (Normal BMI: 53.3% superior vs 39.4% On-ASIS, Overweight: 47.8% superior vs 34.7% On-ASIS). Conclusions: Utilizing CT scans to confirm ASBS and lap belt placement relative to the ASIS, superior belt placement above the ASIS was associated with elevated BMI and a trend of increasing incidence of internal abdominopelvic organ injury.