The sacroiliac joint is a synovial joint located between the two pelvic bones (sacrum and illium) at the back of the pelvis. Majority of injuries to the SI joint are due to excessive movement in the joint which causes the ligaments and tissues structures that support the joint to be overstretched. The repetitive load applied to the surrounding structures causes an inflammatory response at the sacroiliac joint which tends to develop into localized low back pain over the involved joint. Excessive bending, lifting and twisting activities all tend to be the most common causes of SI joint injuries.
Signs and Symptoms:
- Localised pain in the low part of the back around the top of the buttocks.
- Often unilateral but can be bilateral.
- May produce referred pain into the groin, back of the leg, or the front and outside of the thigh.
- When acute, pain is sharp and stabbing and is relieved by sitting or lying.