PSOAS AND ILIACUS MUSCLKs. 



369 



belly ; and in flexing the hip-joint the psoas is always combined 



with the iliacus. withiliacus, 



When the lower limbs are fixed the two muscles will draw forwards or to bend 

 the lumbar part of the spine, and bend the hip-joints, as in stooping 



to the ground. One muscle under the same circumstances can 

 incline the spine laterally. 



The PSOAS PARVUS (fig. 138, E) is a small inconstant muscle, with Psoas 

 a long tendon, which is placed on the front of the large psoas. Its origin 3 ; ' 

 fibres arise from the bodies of the last dorsal and first lumbar 

 vertebrae, with the intervening fibro-cartilage. Its tendon becomes 

 broader below, and is inserted into the ilio-pectineal eminence and insertion ; 

 the brim of the pelvis, joining the iliac fascia. 



Obliquus abdominis 



internus. 

 Quadratus luraborum. 



Multifidus 

 spinae. 



Cocc.ygeus. 

 Levator ani. 



Rectus femoris. 

 Psoas parvus. 

 Pectineus. 



Rectus 

 abdomiuis. 



Levator ani. 



Compressor 

 urethra. 



Erector penis. 



Trans versus perinei. 

 FIG. 139. Os INNOMINATUM INNER AND ANTERIOR VIBW. 



Action. This muscle aids in flexing the lumbar portion of the use. 

 spine, either drawing forwards the upper part of the trunk, or raising 

 the front of the pelvis, according to which end is fixed. 



The ILIACUS MUSCLE (fig. 138, H) occupies the iliac fossa on the iiiacus has 

 inner aspect of the hip-bone, and is blended inferiorly with the 

 psoas. It is triangular in form, and has a fleshy origin from the iliac 

 fossa (fig. 139), and slightly from the ala of the sacrum and the 

 anterior sacro-iliac ligament The fibres pass obliquely inwards to 

 the tendon of the psoas, uniting with it down to its insertion into the insertion ; 



D,A. B B 



