The sacroiliac joint lies next to the spine and connects the sacrum with the pelvis. This joint can be a source of pain, usually due to an alteration in normal joint motion. Sacroiliac joint hypermobility, refers to increased and/or abnormal movement of the joint. The condition is the result of the joint becoming too loose and the ligaments designed to hold it in place have become overly loose.
Pain from a hypermobile sacroiliac joint can be sharp and intense. It is typically felt on one side of the low back or buttocks, and can radiate down the leg.