The purpose of this study is to present an analytical technique to evaluate the nonlinear, coupled stiffness characteristics of the human knee joint. In the present work, a model of the knee is developed which permits the contribution of the ligaments to the nonlinear, coupled stiffness characteristics of the knee to be determined from their nonlinear load-elongation properties, the geometric location of their insertion sites, and the relative position of the femur with respect to the tibia. Calculations with the model are compared to those obtained using Crowninshield, et al. [1] model and experimental data.
