Abstract

The purpose of this study is to determine the effect of active muscle on lower limb injury in frontal vehicles collision, and to provide corresponding biomechanical parameters for the protective design of lower limbs. Based on a Chinese 50th percentile male lower extremity anatomy information, a human body numerical model with active muscle signals during emergency braking is established. A real vehicle model with a defined constraint system is combined with the human body model to build a crash environment of frontal impact. Nine different occupants’ postures with or without active muscle variables in lower limb are set in terms of the variation of different hip joint postures. The tests were performed under the regular test and the results of dynamic responses were compared to determine the effect of active muscle and hip postures on lower limb injuries in knee, thigh and hip during frontal collision. Results show that active muscle function causes a significant decrease in the risk of pelvic and right femur injuries in standard sitting position. With the active muscle function, the vulnerable part of the pelvis is transferred from the back of the hip joint to the lower side, and the vulnerable area of the femur spreads from the hip joint to the knee joint. The risk of pelvic injury increases when the thigh is rotated inside or outside, and this risk increases when the thigh is rotated upward. Results can explain the differences in the statistics of lower limb injuries in trials and accidents.