In order to analyze the human properties for impacts, authors are developing the finite element (FE) model of the whole human body. In this report, the FE model of the lower extremity was developed and validated to analyze the impact responses of the lower extremities. Furthermore, the injury mechanism of the lower leg was investigated using this model. The results are as follows: 1) The FE model of the lower extremity was found to have good agreement with experiments, and 2) In case of toe impact, the results acquired from the simulations could explain one of the injury mechanisms in actual front impact situations.