Influence of Human Body Size on Lower Limb Injury Parameters in Car-Pedestrian Collisions

Lower extremities are the most vulnerable parts in vehicle-pedestrian traffic accident. At present, EC78/2009 (European Community.No78/2009) and GTR9 (Global Technical Regulation.No.9) are the major regulations of pedestrian protection. A fixed mass and length of lower leg impactor is applied to predict the lower limb injuries in these regulations. But, in the real world, the pedestrian's body characteristics, such as height and weight, are significantly different, therefore there may exist certain limitations in the present regulations for testing the injury parameters of lower limbs. In current study, three typical car models and three different percentile pedestrian models were established using multi-body dynamics method. Then the influence of pedestrian weight and height on lower limbs injuries were thoroughly investigated by comparing the tibia acceleration, shear displacement and bending angle of the knee. The results showed that the maximum knee shear displacement rose up as the height and weight of pedestrian models increased. While the knee bending angle was greatly affected by the collision location of the vehicle to pedestrian, the collision position was closer to the knee joint, the bending angle was bigger. The maximum tibia acceleration illustrated different variation tendency with the change of vehicle front structure.