Posterior Sacroiliac Ligament

The posterior sacroiliac ligament is one of the ligaments of the sacrum. The sacrum, at the base of the vertebral column, is wedged between the coxal bones of the pelvis and is united to them by fibrocartilage at the sacroiliac joints. The weight of the body is transmitted to the legs through the pelvic girdle at these joints. The posterior sacroiliac ligament is the fibrocartilage at the back of the sacrum, which joins it to the ilium.