Development And Validation Of A Finite Element Model Of Human Lower Extremity For Dynamics Analysis

The lower extremities are frequently injured by vehicle front structures in vehicle-pedestrian crashes. In order to investigate biomechanics responses of the lower extremity to a lateral bumper impact and injury mechanisms, a 3D finite element (FE) model of the human lower extremity was developed and presented in this paper.The FE model was based on anatomical structure of lower extremity which consists of the pelvis, the femur, the tibia, the fibula, the patella, the foot bones, primary tendons, capsules, and ligaments. The geometry data of the extremity was obtained from Viewpoint Company. The mass distribution and material properties of the bones and soft tissues were based on biomechanical data from the published literature. The model was constructed using shell and linear spring-damper elements, including 13861 nodes and 18966 elements. The boundary and loading conditions were defined in accordance with the configuration of a car-pedestrian lateral collision.The model was implemented by using the finite element program LS-DYNA3D. The validity of the tibia segment model was evaluated against three point bending test in terms of tibia stress. The whole model was validated by using shearing and bending test data in terms of tibia displacements. An analysis was performed in terms of the dynamic response and stress distribution of the lower extremity in lateral impact loading. The relations between impact location and lower extremity injury risk were analyzed.The numerical results indicated that the depressed bumper height can reduce the risk of lower extremity injury. The model enabled to study biomechanics response and injury mechanisms of the lower extremity by means of stress analysis. The model has a high bio-fidelity and will contribute to the research on lower extremity injury mechanisms and development of injury protective device.