Dynamic contribution of muscle forces to ACL loading during sidestep-cutting maneuvers

Abstract

Knee is one of the most frequent-injured joints in the human body, in which anterior cruciate ligament (ACL) rupture is common serious and frequent injury. However, since it is difficult to measure the ACL loading during motion in vivo, it is still not clear which muscles generate ACL loading and what roles of these muscles playing in cutting maneuvers. Therefore, the purpose of this study was to quantify the dynamic contribution of the muscle forces to the ACL loading and ground reaction forces (GRF) generated during sidestep-cutting maneuvers based on multi-body dynamics using a musculoskeletal modelling method. Three-dimensional movement analysis was carried out to investigate five female participants performing anticipated 90° sidestep-cutting maneuvers. Trajectories of 49 marker on the body and GRF of the support leg were measured with VICON-MX system and a force plate, respectively. ACL forces were estimated by optimizing calculation to be equal to the horizontal component of the tibia force generated by muscles during the first 50ms of the contact phase. The results indicate that 1) quadriceps muscles mainly contributed positively to the ACL tension, and it contributed to braking in the approaching direction, and 2) hamstrings muscles mainly contributed negatively to the ACL tensions and positively to the ground reaction force in the cutting direction.