The functional anatomy of tensor fasciae latae and gluteus medius and minimus
Gottschalk, F.; Kourosh, S.; Leveau, B.
Journal of Anatomy 166: 179-189
1989
ISSN/ISBN: 0021-8782 PMID: 2621137 Document Number: 328305
The standard anatomical and functional descriptions of the gluteus medius and minimus are related to an arbitrary two dimensional biomchemical model, which does not provide a coherent view of the hip abductor system. A more accurate description of the anatomy of the gluteus medius and minimus and tensor fasciae latae has been identified. Gluteus medius has three parts each separately innervated. Electromyographic studies have been done and show that the three parts of the gluteus medius muscle have a phasic function from posterior to anterior and that the muscle is not a mass action on-off muscle. Based on the detailed definition of the anatomy and innervation of the muscles, a three dimensional biochemical model of the hip abductor system is presented. Tensor fasciae latae is proposed as the principal abductor. The posterior part of gluteus medius and the whole of gluteus minimus fire at heel strike to stabilize the femoral head in the acetabulum. The middle part of gluteus medius fires during midstance and the anterior part acts as a pelvic rotator to rotate the opposite side of the pelvis forward. The tensor fasciae latae is at a mechanical advantage to exert the necessary force to counterbalance the force of weight during the full stance phase of the gait cycle. By resolving the line of action of the gluteus medius into three resultant forces we have obtained a more accurate picture of this muscle's action.