Analysis of the functional adaptation of biological tissues and its application to mechanical design

点击翻译按钮获取中文摘要

We have been studying adaptation of tendons and ligaments to mechanical environments at various structure levels. In the present study, considering a locational dependence of applied stress to the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), a relationship between the load distribution in the ligaments under anterior-posterior drawer load and their mechanical properties was determined at different flexion angles. The following findings were obtained.1) ACLThe load carried by the ACL depended on both the flexion angle and ligament bundle. In extension, the posterolateral (Pl) bundle carried more load than the anteromedial (AM) portion did. As the flexion angle increased, the load carried by the AM portion icreased while that carried the PL portion decreased. The mechanical property of the ACL was also dependent on both the flexion angle and ligament bundle. As the flexion angle increased, the stiffness of the PL bundle increased.2) PCLBoth the load carried by the PCL and the mechanical property of the PCL were dependent on the ligament bundle. The anterolateral bundle always carried a considerable load, while the stiffness of the bundle was always great.These findings indicate that the load distribution corresponds to the distribution of mechanical properties in the cruciate ligaments at different flexion angles. This suggests that the knee joint is optimally designed so that its ligaments function most effectively at specific flexion angles, and that the external and internal loading to the knee maintains the uniformity of the optimal structure and property. It is possible that this mechanism could be applied to the development of a novel mechanical design.