Abstract
The purpose of this study was to determine the causes other than pain and leg-length discrepancy that could generate the limping found in the frontal plane in patients with osteoarthritic hip. Subjects were 34 patients with osteoarthritic hip, who were divided into four groups according to the degree of limping in the frontal plane. The isometric torque of the hip abductor muscles was measured using a REHAMATE kinetic evaluation and training machine. In addition, measurements of range of motion (ROM) and on roentgenograms of the hip joint were performed.
Major findings of this study were:
1. Superolateral displacement of the femoral head seen in patients with osteoarthritis of the hip increased significantly as limping appeared and developed (p < 0.05).
2. The hip abductor muscle torque decreased significantly when limping developed terminally (p < 0.05).
3. Except for extension, ROM of the hip was maintained for a normal gait in all four groups; there were no significant differences in extension among the four groups.
It is postulated that both weakness of the hip abductor muscles and superolateral displacement of the femoral head are major causes of the limping found in the frontal plane in patients with osteoarthritic hip.
