HIP-JOINT FORCES DURING LOAD-CARRYING

In some diseases affecting only 1 hip joint, it is necessary to keep t he contact force between femoral head and acetabulum (hip joint force) permanently low at the affected side, Six subjects were examined whil e they were walking and carrying a load in 1 or 2 hands, It was determ ined how the forces in both hip joints are influenced by the magnitude of the load and the manner in which it is carried, A mathematical mod el was used to calculate the maximum forces in the frontal plane, One subject had instrumented endoprostheses implanted in both hips, For hi m the measured values were slightly higher than the calculated ones, b ut the overall results were similar, Carrying a load on 1 side keeps t he force constant at the ipsilateral hip joint or even slightly lowers it, At the same time, there is a large increase on the opposite side, Carrying 25% of body weight with 1 hand causes about 2/3 higher force s in the contralateral joint than on tile loaded side, If this load is evenly distributed between the 2 sides, both hip joint forces increas e by 25%, In unilateral load carrying, additional relief of the ipsila teral joint can be achieved if the upper body is held upright and the loadcarrying arm is abducted, such as when using a large shopping bask et.