Angular displacement of the pelvis and the lumbar spine was measured in a group of 19 patients with unilateral osteoarthrosis of the hip joint and a group of 10 control subjects of similar ages for comparison, and the means for each were calculated. All of the patients showed an increase in both sagittal plane (P less than 0.005) and coronal plane (P less than 0.01) movements of the pelvis, when compared with the control group. Two patterns of spinal movement were evident. One group showed a significant decrease in coronal plane movements and the other group showed a significant increase in coronal plane movements. Characteristic patterns of movement were identified and the variations between different patients recorded.