Global Quasi-Static Mechanical Characterization of the Human Knee Under Single- and Multi-Axis Unconstrained Loading Conditions

A substantial number of knee injuries are reported in the United States annually, and are principally observed among young athletes. ACL (anterior cruciate ligament) injury is one of the most common and devastating knee injuries [1]. Many factors influence such injuries, from anatomical variability to magnitude and direction of loading. A better understanding of knee biomechanics and injury mechanisms may improve current preventative, surgical and rehabilitation strategies, and thus, mediate injury risk. Considerable study of knee joint biomechanics under various modes of loading has been undertaken [2–4]. Additional work is needed to characterize the effects of different loading factors on knee biomechanics, especially ACL loading patterns under more physiologically relevant conditions. The purpose of this study is to develop a new technique to investigate the effects of various single- and multi-axes loading conditions on knee kinematics, ACL and MCL (medial collateral ligament) strains, and TF (tibiofemoral) articular cartilage pressure distribution under quasistatic loading conditions that simulate various weight bearing activities.