New injury reference values determined for TRL legform impactor from accident reconstruction test

New injury reference values for evaluation of injury risk to pedestrian leg by means of the legform impactor with rigid leg and thigh developed by the Transport Research Laboratory (TRL) are proposed in the present study. Lower extremity responses related to the risk of pedestrian leg injuries induced by the bumper contact in a real-world pedestrian accident, such as knee angle and lower leg acceleration in the impact direction, were reconstructed using this legform impactor. The injury reference values for the TRL legform impactor for estimation of the risk of collateral ligament injury and tibia fracture were determined from application of t-test and the maximum likelihood method of logistic regression to these responses. Furthermore, the bumper areas that cause the most severe lower extremity injuries in car-pedestrian impacts were identified from in-depth accident databases in Japan.