Abstract
Simple goniometer for hip joint was developed utilizing universal joint. It uses two angular sensors and a displacement meter of the strain gauge-type. Accurate positioning is not necessary for the goniometer developed, which was the problem of conventional goniometer. Basing upon a mechanical model, the center of hip joint was estimated theoretically by the least-square method. The slide tracks on a femoral head were calculated. According to the results, characteristic patterns were obtained that reflected the way of walking of each subject.
