Computer simulations of obesity effects on occupant injury in frontal impacts

Abstract

Obese occupants in motor-vehicle collisions experience different injury risks compared to non-obese occupants and there is little data available to explain these differences. The purpose of this study was to examine mechanisms of injury and injury risk to obese male occupants in frontal motor-vehicle collisions. Computer models were created to investigate the contributions of increased occupant mass and the interaction between the obese torso and seatbelt on occupant injury risk. A design-of-experiments approach was used to investigate the effects of body mass index (BMI) on occupant injury while controlling for vehicle environment variables. Results suggest that occupant mass is the most significant factor contributing to different injury risks in obese occupants. Changes in obese torso/seatbelt interaction, due to increased BMI alone, do not significantly affect occupant injury risk. However, changes in torso/seatbelt interaction coupled with increased occupant mass alter the overall kinematics of the occupant causing increased risk of injury to the lower extremities.