The Gluteal Region. 309 



fibres of the lower half going to the fascia lata, while the 

 deeper portion of the lower half is inserted into the femur. 

 Actions. It is an external rotator and an extensor of the 

 thigh, the latter action being pronounced when an extra 

 effort is required for extension, as in climbing a hill, or in 

 jumping, etc. the ordinary extension that takes place in 

 walking on the level being the result of the action of the 

 hamstring muscles. Acting from below, the gluteus max- 

 imus extends the pelvis on the femora, so as to bring the 

 body to an erect position. One of the distinguishing fea- 

 tures of lumbago is pain on attempting to assume the erect 

 posture after stooping, and this is due to the fact, that a 

 portion of the gluteus maximus arises from the fascia 

 covering the muscles affected in lumbago, and consequent- 

 ly, when the patient raises his body from the stooping pos- 

 ture, the traction on this fascia by the gluteus maximus 

 causes pain. 



Gluteus Medius. From the anterior four-fifths of the 

 crest of the ilium and from the outer surface of the bone 

 between the superior and the middle curved lines ; into the 

 oblique line running downwards and forwards on the 

 outer surface of the great trochanter. The gluteus maxi- 

 mus covers the posterior third of this muscle. Actions. 

 It is an abductor of the thigh, and can rotate the limb, by 

 its anterior fibres, inwards, and, by its posterior fibres, 

 outwards. Acting from below, it balances the pel- 

 vis when the opposite limb is raised from the ground, 

 and is, therefore, brought into play in walking, whereas, 

 in fast walking, it rotates the opposite side of the pelvis 

 forward and thus increases the length of the stride. 



Glutus Minimus. From the outer surface of the 

 ilium between the middle and the inferior curved lines 

 and from the margin of the great sacro-sciatic notch ; into 

 the anterior border of the great trochanter. Its actions 

 are similar to those of the gluteus medius. 



