Stress distribution on the hip joint articular surface during gait.

The magnitude and the direction of the resultant hip joint force are different in different body positions during gait. Therefore the stress distribution in the hip joint articular surface also changes. The aim of this work is to study how the stress distribution changes if the magnitude and the direction of the hip joint force is changed during gait. For this purpose a three-dimensional mathematical model is developed. We calculated the values of the peak stress and the location of the pole on the articular surface (where the stress is maximal) in the successive phases of the walking cycle. The values of the peak stress range from 0.8 MPa in the one limb stance phase to 2.6 MPa in the heel strike phase.