30 LIGAMENT>S AND MUSCLES OF THE HORSE. 



SUBLUMBAR REGION. 



1. Psoas ma gnus. 4. Quadratus lumborum. 



2. Psoas pai'viis. 5. Intertransversales lumborum. 



3. Iliac lis. 



1. Psoas Magxus. 



Origin. — From the inferior surface of the bodies of the last two 



dorsal vertebrae, last two ribs and transverse processes of 



lumbar, except the last. 

 Insertion. — To the internal trochanter of the femur. 

 Actio7i. — Flexion, and outward rotation of hip joint. If hind 



limb is fixed, both muscles will arch the loins ; or singly, 



incline the trunk to one side. 



2. Psoas Parvus. 



Origin. — From the bodies of last four dorsal and all the lumbar 



vertebra^. 

 Insert'* on — To the ilio-pectineal line. 

 Action. — Both muscles flex the pelvis on the loins ; singly, cause 



lateral motion. 



3. Iliacus. 



Ori^i?^.— From the venter surface and external angle of the 



ilium and sacro-iliac ligament. 

 Insertion. — To the internal trochanter of femur. 

 Action — Similar to Psoas Magnus. 



4. QuADRATus Lumborum. 



Attachments. — To the tips of the transverse processes of the 

 lumbar vertebrae, last three ribs, and sacro-iliac ligament. 



Action. — 'Sf it\\ muscles fix the last ribs and thus assist the 

 diaphragm. Singly, lateral bending of the loins is pro- 

 duced. 

 T). Intertransversales Lumborum. 



These connect adjacent transverse processes, and assist preceding 

 muscle. 



