The influence of body mass index on thoracic injuries in frontal impacts.

For this study, a comprehensive analysis was performed to assess the influence of body mass index on thoracic injury potential. The data for this study were obtained from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database for years 1993-2005. Obese occupants had a 26 and 33% higher risk of AIS > or = 2 and AIS > or = 3 thoracic injury when compared to lean occupants. The increased risk of AIS > or = 3 injury due to obesity was slightly higher for older occupants, but the influence of age was greater than that of obesity. The increase in injury potential was higher for unbelted obese occupants than unbelted. Non-parametric and parametric risk curves were developed to estimate the risk of thoracic injury based on occupant BMI, belt use and delta-V. Overall, increase in thoracic injury risk due to obesity is more prominent in males and older occupants and for occupants sustaining AIS > or = 3 thoracic injuries.