The effect of automatic brake system on the response of the lower limbs based on active muscle force

This article employs a finite element model integrated with the Hybrid III dummy to investigate how automatic braking and active muscle forces influence lower-limb injuries in frontal collisions. Prolonged braking can increase the tibial index, indicating more severe injury to the lower leg. Braking mitigated thigh injury at 50 km/h but exacerbated it at 40 km/h. Active muscle activation increased the femoral axial force and tibial index but decreased tibial and fibular peak stresses by approximately 0.006-0.009 GPa. These findings highlight the complex role of braking and muscle activation in lower-limb injuries and inform the development of advanced safety system designs.