214 



THE MUSCLES. 



the origin of the anterior straight muscle of the thigh, from which it is 

 separated by a space filled with fat ; inwardly, with the crural vessels. It 

 passes between the vastus internus and the pectineus, to reach the 

 trochanter. 



Actions. It is a flexor and rotator outwards of the thigh. 



4. Small Psoas Muscle. (Fig. 108, 2.) 



Synonyms. Psoas of the loins Bourgelat. Sublumbo-pubialis, or sublumbo-iliacus, 

 according to Girard. (Psoas parvus Percivall. The lombo-iliacus of Leyh.) 



Situation Form Structure. Placed at the inner side of the great psoas, 

 very much elongated, and semipenniform in shape, this muscle is terminated 

 behind by a flattened tendon, and is composed of fleshy fibres, the longest of 

 which are anterior. These fasciculi are all directed backwards and outwards 

 to gain the tendon. 



Attachments. 1, To the bodies of the three or four last dorsal, and to all 

 the lumbar vertebrae, by the anterior extremity of its fleshy fibres ; 2, To 

 the ilio-pectineal eminence and the lumbo-iliac aponeurosis, by the posterior 

 extremity of its tendon. 



Relations. By its inferior face with the pleura, the superior border of the 

 diaphragm, the aorta or posterior vena cava, and the great sympathetic 

 nerve ; by its upper face, with the psoas magnus. It is traversed, near its 

 vertebral insertions, by numerous vascular and nervous branches. 



Actions. It flexes the pelvis on the spine, when the loins are the fixed 

 point ; but should the pelvis be fixed, it arches or laterally inclines the lumbar 

 region. It is also the tensor muscle of the lumbo-iliac aponeurosis. 



109 - 5. Square Muscle of the Loins. 



(Fig. 109, 1.) 



Synonyms. Sacro-costalis 

 Girard. (Sacro-lumbalis Percivall. 

 Quadratus lumborum of Man.) 



Situation Form Structure 

 Attachments. This muscle is 

 comprised between the trans- 

 verse processes of the lumbar 

 region and the great psoas, and 

 is elongated from before to be- 

 hind, flattened above and below, 

 and divided into several very 

 tendinous fasciculi. The prin- 

 cipal fasciculus, situated out- 

 wardly, takes its origin from 

 the sacro-iliac ligament, near 

 the angle of the sacrum, and ex- 

 tends directly forward to gain 

 the posterior border of the last 

 rib, after being attached by its 

 upper face to the summits of the 

 transverse processes of the lum- 

 Quadratus lumborum ; 2, 2 Intertransversales ; bar ver tebrJE. The other fasci- 

 o, omall retractor muscle or the last rib a de- T i j. r 



pendent of the small oblique of the abdomen. cuh are J on 8P r as they are an- 



terior; they leave the internal 

 border of the first, and are directed obliquely forward and inward, to be 



DEEP MUSCLES OF THE SUBLUMBAR REGION. 



