THE ABDOMEN 



767 



Insertion. — (i) The outer aspect of the tendon of the psoas 

 magnns ; (2) the triangular surface which is situated below, and in 

 front of, the smcJl trochanter of the femur (between it and the spiral 

 line) ; and (3) the iho-femoral ligament. The fibres inserted into 

 the ilio- femoral ligament are those which arise in the region of the 

 anterior inferior iliac spine. They are sometimes separated from 

 the rest of the muscle, and are then known as the iliacus minor or 

 Uio-capsiilaris. 



Nerve-supply. — ^The anterior femoral nerve. 



JW Twelfth Rib 



Quadratus Lumbonun - 



PyrifiWTiiis 



Small Sacro-sciadc 

 - - Ligament 



Great Sacro-sdatic 

 r - Ligament 



Obturator Eztemus 



Fig. 3-29. — The Psoas, Iliacus. and Quadratos Lumboruh Muscles. 



- Action. — Acting from its origin the muscle is a flexor of the thigh 

 upon the pelvis. Acting from its insertion it is a flexor of the peh-is 

 upon the thigh. 



Quadratus Lumborum— Ong'tn.— (i) The ilio-lumbar ligament; 

 (2) the inner lip of the crest of the iliiun for about 2 inches behind 

 and outside the Uio-lumbar ligament ; and (3) the tips of the trans- 

 verse processes of the lower three or four lumbar vertebrae. 



Insertion. — (i) The lower border of the last rib along its inner 

 half, and {2) the tips of the transverse processes of the upper three or 



