Sacroiliac Joint Pain

The sacroiliac joint is where the sacrum, at the base of the spine, connects with the two large bones of the pelvis, or the iliac bones. Pain may be due to pregnancy, tight muscles, arthritis, wear on cartilage between bones, trauma, or a history of injuries. The pain may occur in the lower back or hip. It may be uncomfortable to stand or bend over after sitting for long periods.