Abstract
A new method was designed for analyzing the three-dimensional location of the muscles around the hip joint. Images of the muscles on X-ray computed tomography of the pelvis and hip joint were input into a computer and the three-dimensional shape of each muscle was reconstructed. As a result, each muscle was located accurately with respect to the center of the femoral head. The direction and magnitude of abduction and resultant force at the hip joint were determined utilizing this method.
In the frontal plane, gluteus maximus M. met the vertical line at 14°, gluteus medius M. at 19°, gluteus minimus M. at 31°, tensor fascia lata M. at 2°, sartorius M. at -18°, iliopsoas M. at 12°, and rectus femoris M. at-8°. In the saggital plane, gluteus maximus M. met the vertical line at-3°, gluteus medius M. at 13°, gluteus minimus M. at 12°, tensor fascia lata M. at 3°, sartorius M. at 2°, iliopsoas M. at 10°, and rectus femoris M. at-9°. In the frontal plane, the direction of the abduction force crossed the vertical line at 16.1°. The magnitude of the abduction force was 1.66 times body weight. The direction of the resultant force at the hip joint crossed the vertical line at 10.2°. The magnitude of the resultant force was 2.81 times body weight.
