Information about the loading of the human acetabulum during walking is necessary for a functional understanding of the morphology of the pelvic girdle and the hip joint as well as for the optimization of endoprosthetic therapy in osteo-arthritis. For this purpose, experimental data of the forces acting on the femur in walking taken from the literature [Bergmann et al.: J. Biomech. 1993;26: 969–990] were combined with our own kinematic and morphometric data, to transform the force vectors from the femoral into a pelvic and an acetabular frame. During the walking cycle, the resultant force vector takes a rather constant course relative to the pelvis and its orientation seems to be highly regulated to act within a small range of angles. Only small deviations occur from the angles against the vertical which the resultant peak force forms in the frontal plane (F=11°, medially orientated) and in the sagittal plane (S = 5°, ventrally orientated). The experimental results form the basis for a model of the incongruous hip joint as an elastic joint, the femoral head being centered between compliant elements.