[Gait analysis of patients with osteoarthritis of the hip and those with total hip arthroplasty].

For the purpose of quantitative evaluation of gait after total hip arthroplasty (THA), the author performed gait analysis using a force plate and a light source spot-measuring device. In this study, the author laid emphasis on measuring the moments of the hip joint on the coronal and sagittal planes, using a rigid body link model. On the sagittal plane, an extension moment began to be noted in the early stance phase. This moment was lower in patients showing escape limping. Flexion moment appeared in the middle to late stance phases. This moment was lower in patients with restricted hip extension. On the coronal plane, an abduction moment appeared in the single stance phase. This moment was lower in patients showing Duchenne limping. Abnormalities in these moments were sometimes observed even in patients in whom distance-related factors, temporal factors, and floor reaction force curves had been normalized. Therefore, the measurement of hip joint moments is expected to facilitate the evaluation of the hip joint function itself, unmodified by the compensatory effects by other joints.