SUBLUMBAR KEGION. 207 



Fleshy above, it has posteriorly a strong flat tendon passing along 

 the lower surface to its insertion. 



Origin. — From the bodies of the last three or four dorsal and 

 all the lumbar vertebrae. 



Insertion. — To the ilio-pectineal eminence on the brim of the 

 pubis, midway between the symphysis and the acetabulum, and 

 to the iliac fascia. 



Relation. — Inferiorly with the diaphragm, pleura, posterior 

 aorta and vena cava ; externally with the psoas magnus. 



Action. — To flex the pelvis on the spine, when the loins are 

 fixed ; when the pelvis is flxed, to arch the back. It is also the 

 tensor of the iliac fascia. 



ILIACUS. 



(^Ilio-trochantineus.') 

 (Fig. 76. d, e.) 



Situated under the false pelvis, this muscle is strong, thick, 

 and pyramidal, the base being forwards, and the fibres extending 

 downwards, backwards, and inwards. The belly is incompletely 

 divided by a fissure into two unequal portions, the external being 

 the larger ; through this fissure passes the tendon of the psoas 

 magnus, which its own tendon joins. 



Origin. — From the ilio-pectineal ridge, nearly all the venter 

 surface of the ilium, and the inferior sacro-iliac ligament. 



Insertion. — To the internal trochanter of the femur, along with 

 the psoas magnus. 



Relation. — Superiorly with the ilium ; inferiorly with the iliac 

 fascia and sartorius ; externally with the tensor fascise latse and 

 rectus femoris, from which it is separated by a layer of fat ; 

 internally with the crural vessels. It passes between the vastus 

 internus and the pectineus. 



Action. — To flex the femur, and rotate it outwards. 



QUADRATUS LUMBORUM. 



{Sacro-lumhalis.) 



(Fig. 76. a.) 



Placed below and between the lumbar transverse processes, this 

 is a flat, thin muscle, consisting of several bundles, with strong 

 tendinous intersections. The principal bundle is situated exter- 



