This paper contains the results of 50% offset frontal collision tests which were conducted in order to analyze impact situation of ankle/foot regions during car-to-car crashes with both 50km/h running speeds. We took high-speed films of the footwell regions, and measured impact forces of Hybrid-III lower legs, three-axis accelerations of the toe-board, floor and brake pedal in the tests. In the same collision configuration, we conducted the tests under four different test conditions of driver seating situations as follows:​ with seatbelts + stepping on the brake pedal, with seatbelts + stepping on the accelerator pedal, without seatbelts + stepping on the brake pedal, and without seatbelts + stepping on the accelerator pedal.

In this paper, we focused on motions and impact forces of lower legs, on intrusions and movements of the floor, toe-board and pedals, and on interactions with them during crashes. The floor, toe-board and pedals were observed to not only longitudinally move or deform but also transversely and vertically, and different motions and varied forces of lower legs were obtained in each of the four test conditions. The test results indicated that it would be necessary to pay attention to the transverse and vertical motions of the occupant and the various sections of the vehicle, and to the foot positions in relation to the foot pedals and floor as well.