The size and the shape of the weight bearing area in adult human hips depen
d on the forces acting in the hip and therefore change during the body moti
on. In this work the size and the shape of the weight bearing area in sever
al phases of gait are estimated. The forces acting in the hip were determin
ed through laboratory measurements and analyzed by mathematical models. The
dysplastic hips are distinguished from the normal ones by a smaller center
-edge angle of Wiberg while the time course of the forces acting in the hip
is assumed to be the same in both cases. It is shown how radial articular
stress is distributed over the weight bearing area in both cases. In normal
human hips the weight bearing area occupies a rather large portion of the
acetabulum-femoral head contact area while in dysplastic hips stress distri
bution is unfavourably concentrated in a smaller weight bearing area.