The Sacroiliac (SI) Joint is positioned in the lower part of the body between the Sacrum, (the big, triangle-shaped bone at the base of your spine,) and the ilium, (the large broad bone forming the upper part of each half of the pelvis.)
This low-motion joint connects the hip bones to each side of the sacrum where the base of the spine meets the pelvis, and acts as a shock absorber between the lower body and torso.
As with any other joint in the body, the SI Joint may become injured or degenerated over time, leading to symptoms of SI Joint dysfunction, inflammation and pain such as: