LIMITATIONS OF QUASI-STATIC ESTIMATION OF HUMAN JOINT LOADING DURING LOCOMOTION

The forces and moments at the ankle, knee and hip joints of the human lower limbs are divided into static and inertial components. They are calculated for various activities ranging from slow walking to running . The relative roles of these two components in the 'total' joint load s are studied, and the limitations of using a quasi-static analysis ap proach for joint load approximation are discussed. The results indicat e that the static loads only reflect the gravitational and external re actions between the body and the environment, whereas the inertial loa ds provide dynamic information on each body segment involved, The effe ct of the inertial forces and moments becomes more important as the sp eed of locomotion increases; where the more proximal joints in the hum an lower extremity are concerned; and where the shear components of th e force and moment are of interest. On the other hand, it seems that m ost of the joint moments in the lower extremity during walking and eve n running could reasonably be approximated by static components.