Mathematical simulations of passive knee joint motions

In view of the complex biomechanical behavior of the knee joint, mathematical simulations of its mechanical behaviour are found to be useful in the scientific process of untwining the complex relationships between the functional biomechanical characteristics and the structural properties. As far as the passive properties are concerned, several three-dimensional models are known. Of the more sophisticated models (1,2) only few results are known. The purpose of the present investigation is to measure and describe the passive freedom-of-motion characteristics of the human knee joint, on a subject-to-subject basis. The approach is to obtain experimentally the passive motion characteristics of the joint for various combinations of external loads and to simulate this behavior in a mathematical model. The geometric properties of the individual joint specimens are measured and are used as input for the model.