A three-dimensional multibody system model of the lower extremity was used to simulate two series of previously performed experiments with lower extremity specimens at lateral impact speeds of 15 and 20 km/h. In the simulation of lateral shearing response of the knee joint, the predicted peak shearing displacement was 8-9 mm during the first 10 ms of the impact. This displacement is the main effect of the intra-articular failure of the knee joint to the lateral shearing force. In simulations of response of the knee joint to lateral bending load, the predicted lateral bending angle was about 8-13 degrees at 20 ms after impact, the corresponding strain of the medial collateral ligament (MCL) was 12-15%. The results confirmed (MCL) was 12-15%. The results confirmed that bending failure of the knee is dominated by the knee lateral rotation during the period of 15-50 ms after impact. The outcomes from the simulations are analysed and discussed in terms of the injury mechanisms of the knee joint. The mathematical modelling of the response of the knee joint to transient shearing and bending loads gives a better understanding of the injury mechanism of this body region in car-pedestrian accidents, and it is able to predict the risk of knee injuries corresponding to these two mechanisms.
Samenvatting