Dynamic contribution of joint torque to knee joint load associated with ACL injury during sidestep-cutting maneuvers

Abstract

Since the anterior cruciate ligament(ACL) rupture is a serious sports injury, it is important to clarify the injury mechanism to establish a preventive method. Although the knee joint valgus torque and knee joint anterior shear forces in sidestep-cutting maneuvers are one of the main risk factors of ACL injury, it is not clear how this torque and force is generated and what role it plays in cutting maneuvers. Therefore, the purposes of this study were to quantify the dynamic contribution of the joint torques to the knee joint valgus torque, the knee joint force, and ground reaction forces(GRF) generated during sidestep-cutting maneuvers based on multi-body dynamics. Three-dimensional movement analysis was carried out to investigate one male participant performing anticipated 90° sidestep-cutting maneuvers. Trajectories of 47 marker on the body and GRF of the support leg were measured with VICON-MX system and a force plate, respectively. Knee joint valgus torque and-, knee joint anterior/posterior force, were calculated during the first 50 ms of the contact phase. The results indicate that 1) internal rotation of the hip joint torque mainly contributed positively to the knee joint valgus torque, and it did not contribute to the ground reaction force, and 2) extension of the knee joint torque mainly contributed positively to the knee joint anterior shear forces, and it contributed negatively to the ground reaction force in the invasion direction.