Kinematical and geometrical analysis of the human knee joint - second part - Using the theory of four-bar mechanism.

Abstract

Kinematics of the human knee joint consist of flexion-extension and “screw home”, some passive varus-valgus and rotation movements during flexion. Two conflicting factors must be satisfied: not only a wide range of movement but also a large load bearing capacity. To evaluate the kinematics quantitatively and mathematically, it is necessary to know the anatomical configuration, structure and mechnics. Few related studies have been done in the past, except for Menscik's descriptive work. In this paper, we described a two-dimensional kinematical knee joint model, which treats both articular surface configurations in the sagittal plane and ligaments, as a single functional unit: a four bar mechanism. Using this model, calculation was made for sectional configurations of femoral condyles and some specific sliding ratios at the contact points. Some of the local regional characteristics were examined.