
The SI joint is the bony pelvis between the sacrum and the ilium of the pelvis which are joined by strong ligaments. This joint does not have much motion and transmits all the forces of the upper body to the pelvis (hips) and legs. It acts as a shock absorbing structure.
As with any joint, the SI joint can become arthritic or its support ligaments can become loose or injured. Dysfunction in the SI joint is thought to cause low back...