Finite Element Analysis of Pedestrian Lower Extremity Injuries in Car-to-Pedestrian Impacts

In order to prevent lower extremity injuries to a pedestrian when struck by a car, it is important to elucidate the loadings from car front structures on the lower extremities and the injury mechanism caused by these loadings. In this study, using a human finite element (FE) model, a bending moment diagram and a stress diagram of tibia were introduced to examine the effects of loading from car structures. By the lower absorber of the car, the bending moment was distributed over the tibia with small moment at the upper tibia location that can reduce knee injury risk. Certain positions of the lower absorber reduced the tibia fracture risk. An FE analysis of a legform impact test using the TRL legform impactor was also conducted, and a relation was found between the injury criteria of the TRL legform impactor and the human FE model. High acceleration of the TRL legform impactor corresponded to the tibia fracture or MCL rupture of the human FE model.