A Statical Model of the Human Knee Joint

摘要

The knee joint is the largest and unprotected synovial joint in the human body. It is called a hinge joint, but actually it is more complicated than that. The knee joins the patella, the distal femoral condyles and the proximal tibial plateaus. It has two degrees of freedom: the first degree involves flexion-extension movement of a 'true hinge joint'; and second degree, involves rotary movement and is only possible in flexion. The present work is an attempt to apply a statical model for the knee joint and to analyze the force during flexed-knee stance with the aid of computed tomography (CT) technique, in order to measure the quadriceps force (FQ), tibiofemoral reactive force (FT), and the patella-femoral joint reactive force (FP). The results showed that the quadriceps and joint reactive forces are greater at higher degrees of knee flexion. The contact forces at the tibio-femoral and patella-femoral are both functions of quadriceps force. The quadriceps force required to maintain a static equilibrium in a flexed-knee stance is a function of body weight and the angle of knee flexion. The results obtained are in fair agreement with some results in literature.