Assessment of Injury Mitigation by Safety Belts in Real World Car Crashes

摘要

Currently, there is common consensus that in car crashes safety belts for the most part are effective to prevent or at least to reduce severe and serious injuries of occupants. However, certain accident situations occur as well, in which belt usage is unclear and divergent opinions arise, whether or not injuries sustained could have been mitigated by safety belts. The objective of this study is to demonstrate such relevant cases and evaluate individually the injury causation relating to seat belt usage. 108 moderate and severe car crashes with unclear belt usage investigated at the Munich University Institute of Legal Medicine within the time period of 2000 to 2011 have been analysed with respect to causation and potential mitigation of injuries with or without seat belt. In all cases detailed accident reconstruction with PC-Crash was performed in order to determine collision severity and vehicle dynamics (Δv, deceleration, EES, intrusion). MADYMO?-Simulations were applied for each case in order to identify the biomechanical loading and injury mechanisms of the occupants - real and fictive - both with and without seat belt. Case by case analysis reflects a number of uncommon injury patterns which exclude safety belt usage as an effective mitigating factor. One tragic example is neck-fracture with complete paraplegia sub C3 in a moderate frontal crash without airbag activation. Other uncommon injury patterns will be presented in the paper. The findings of the study suggest that in 80% of the cases the injuries sustained would have been prevented or at least mitigated when using the seat belt. This means that in these particular cases safety belts were definitely not worn or used incorrectly, even sometimes with an activated airbag. In special impact situations, safety belts could not prevent or reduce the injuries sustained, e.g. lateral impacts with extensive intrusion, rollover crashes with ejection, under riding of trucks.