SUBLUMBAR REGION. 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 sympbysis 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 fixed, to arch the back. It is also the 

 tensor of the iliac fascia. 



ILIACUS. 



(Ilio-trochantineus.) 

 (Fie. 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 

 inagnus, which its own tendon joins. 



Origin. From the ilio-pectineal ridge, nearly all the veneer 

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



Insertion. To the internal trochanter of the femur. alon<y with 



' O 



the psoas magnus. 



Relation. Superiorly with the ilium ; inferiorly with the iliac 

 fascia and sartorius ; externally with the tensor fasciaB lara? 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. 



QUADRAfUS LUMBORUM. 



(Sacro-lumbalis. ) 



(Fie. 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- 



