Posterior sacroiliac ligament
The posterior sacroiliac ligament is situated in a deep depression between the sacrum and ilium behind; it is strong and forms the chief bond of union between the bones.
It consists of numerous fasciculi, which pass between the bones in various directions.
- The upper part is nearly horizontal in direction, and pass from the first and second transverse tubercles on the back of the sacrum to the tuberosity of the ilium.
- The lower part is oblique in direction; it is attached by one extremity to the third transverse tubercle of the back of the sacrum, and by the other to the posterior superior spine of the ilium.