The most common symptoms for patients are lower back pain and the following sensations in the lower extremity: pain, numbness, tingling, weakness, pelvis/buttock pain, hip/groin pain, feeling of leg instability (buckling, giving way), disturbed sleep patterns, disturbed sitting patterns (unable to sit for long periods, sitting on one side), pain going from sitting to standing.
Causes and Risk Factors
While it is not clear how the pain is caused, it is thought that an alteration in the normal joint motion may be the culprit that causes sacroiliac pain. This source of pain can be caused by either:
Too much movement (hypermobility or instability): The pain is typically felt in the lower back and/or hip and may radiate into the groin area.
Too little movement (hypomobility or fixation): The pain is typically felt on one side of the lower back or buttocks and can radiate down the leg. The pain usually remains above the knee, but at times pain can extend to the ankle or foot. The pain is similar to sciatica — or pain that radiates down the sciatic nerve — and is caused by a radiculopathy.