246 



THE MUSCLES OF THE LOWER LIMB. 



on the glutens medius and pyriformis muscles, the tendon of the obturator internus with the 

 two gemelli, the quadratus femoris, a small portion of the adductor magnus, the great tro- 

 chanter, the ischial tuberosity, and the origins of the hamstring muscles ; it covers also the sciatic 

 vessels and nerves as they emerge from the pelvis below the pyriformis, the superficial branch 

 of the gluteal artery passing out above that muscle, and the pudic vessels and nerve lying 

 behind the spine of the ischium. 



Between the fascial insertion of the muscle and the great trochanter is a large multilocular 

 bursa, or there may be two or three smaller ones, and another intervenes between it and the 

 upper part of the vastus externus. In some cases there is also a bursa over the ischial 

 tuberosity. ' 



The great size of the gluteus maximus, and the consequent prominence of the buttock, is- 

 a characteristic of man as compared with those animals which most nearly approach him in 

 general structure. 



Varieties. These are not frequent. The muscle has been seen receiving an additional 

 fasciculus of origin from the lumbar aponeurosis, or from the ischial tuberosity. A distinct slip 

 at the lower border arising from the coccyx occasionally represents the agitator caudce of the 



Fig. 250. DEEP MUSCLES OF THE HIP ON THE LEFT SIDE,. 



FKOM BEHIND. \ 



The gluteus maximus, and the muscles of the thigh have 

 been removed. 1, 1, gluteus medius ; 2, pyriformis ; 3, 

 gemellus superior ; 4, gemellus inferior ; 5, obturator in- 

 ternus, seen partially within the pelvis, and, after issuing 

 by the sciatic notch, between the gemelli muscles ; 6, quad- 

 ratus femoris ; 7, tendon of the obturator externus between 

 the gemellus inferior and quadratus. 



lower animals. The fibres arising from the sacro- 

 sciatic ligament and the margin of the sacrum are 

 normally separated by a layer of areolar tissue from 

 the superficial portion, and a powerful development 

 of the deep part has given rise to the bilaminar con- 

 dition described by Tiedemann and others (Henle). 



The gluteus medius muscle, covered partly 

 by the gluteus maximus, partly by the fascia 

 lata, arises from the surface of the ilium between 

 the crest, the posterior and the middle gluteal 



lines, and in front of the gluteus maximus from the strong fascia covering its outer 

 surface. The muscular fibres converge as they descend, the anterior fibres passing 

 obliquely backwards, the posterior fibres obliquely forwards, and terminate in a 

 flattened tendon, which is inserted into an oblique impression directed downwards 

 and forwards on the outer surface of the great trochanter. The tendon is separated 

 by a small bursa from the upper part of the trochanter. 



Relations. Between this muscle and the gluteus minimus are the superior gluteal nerve 

 and the deep branches of the gluteal vessels. At its anterior border its fibres are parallel to 

 and generally united with those of the gluteus minimus. This border also is overlapped by 

 the tensor vaginae femoris. The posterior border is in contact with the pyriformis, the super- 

 ficial part of the gluteal vessels passing between the two. 



Varieties. Some of the deeper fibres of the muscle occasionally end in a separate tendon 

 which is inserted into the upper border of the great trochanter. The posterior border of the 

 muscle is sometimes closely united to the pyriformis, or some of the fibres end on the tendon 

 of that muscle. A bursa is occasionally present between the tendon of this muscle and the 

 pyriformis (1 in 15, Macalister). 



The gluteus minimus, covered by the preceding muscle, arises from the whole 

 space on the ilium between the middle and inferior gluteal lines. The fibres, con- 

 verging as they descend, terminate in an aponeurotic tendon on the outer surface of 

 the muscle, which becoming narrowed is inserted into an impression on the front of 

 the great trochanter. The tendon is bound down to the prominence of the trochan- 



