148 ARTICULATIONS OF THE PELVIS. 



the ilium which projects beyond the dorsum of the sacrum. A superficial 

 band extending downwards from the posterior superior iliac spine to the 

 third or fourth piece of the sacrum, in a direction different from the other 

 fibres, is distinguished as the oblique sacro-iliac ligament. 



The anterior sacro- iliac ligament consists of thin irregular fibres passing 

 between the sacrum and os innominatum on their pelvic surfaces. 



Fig. 136. 

 i 



Fig. 136. ARTICULATIONS OF THE PELVIS AND HIP-JOINT, SEEN FROM BEFORE. THE 



ANTERIOR HALF OF THE CAPSULAR LlGAMENT OF THE LEFT HlP-JoJNT HAS BEEN 

 REMOVED, AND THE FEMUR ROTATED OUTWARDS. \ 



1, 1, anterior common ligament of the bodies of the vertebrae passing down over the 

 two lowest lumbar vertebrae to the front of the sacrum and coccyx ; 2, ilio-lumbar liga- 

 ment ; 3, anterior sacro-iliac ligament ; between 2 and 3, on the right side, the sacro- 

 vertebral ligament is shown, but not with sufficient distinctness ; 4, placed in the great 

 sacro-sciatic foramen, points to the lesser sacro-sciatic ligament ; 5, a portion of the great 

 sciatic ligament ; 6, the anterior ligament of the symphysis pubis ; 7, the obturator 

 membrane or ligament ; 8, the capsular ligament of the right hip-joint : the figure is 

 placed on its ilio-femoral band ; 9, the upper part of the divided capsular ligament of the 

 left hip-joint near the place of its attachment to the border of the acetabulum ; 10, placed 

 on the os pubis of the left side above the transverse ligament of the acetabular notch. 

 The head of the femur is withdrawn partially from the socket, so as to show the round 

 ligament stretched from the transverse ligament. 



THE SACRO-SCIATIC LIGAMENTS. The posterior, or great sacro-sciatic liga- 

 ment, elongated, broad, and triangular, is placed at the inferior and poste- 

 rior part of the pelvis, whose lower aperture it assists in closing. Its base 

 or broader part is attached to the postero-inferior iliac spine and to the 

 side of the sacrum and coccyx ; whilst its other extremity is fixed along the 

 inner surface of the ischial tuberosity, where it expands somewhat, and 

 sends upwards and forwards along the margin of the ischial ramus a falci- 

 form process, the border of which is continuous with the obturator fascia, 

 forming the inferior attachment of that structure. 



The anterior, or small sacro-sciatic ligament, much shorter and thinner 

 than the preceding one, in front of which it lies, is attached by its base 



