Sacroiliac Joint Anatomy :
The sacroiliac joint connects the sacrum (triangular bone at the bottom of the spine) with the pelvis (iliac bone that is part of the hip joint) on each side of the lower spine. It transmits all the forces of the upper body to the pelvis and legs. There is not a lot of motion in the joint and it is very strong and stable.
It is not clearly understood why sacroiliac joint dysfunction occurs, although some believe it is due to a limitation in its normal motion patterns and/or misalignment of the joint. Sacroiliac joint (SI joint) pain typically results in pain on one side very low in the back or in the buttocks. Another term for sacroiliac joint pain is sacroiliitis, a term that describes inflammation in the joint.
Sacroiliac Joint Dysfunction Symptoms
SI joint problems are a common cause of low back pain. Additional symptoms may be characterized by the following:
- Pain in the thigh and/or buttock, and possibly pain that radiates down the sciatic nerve, although it rarely radiates into the foot
- More commonly experienced on one side of the body, but may occur on both sides
- More commonly found in young or middle age women.