br Dr. Guevarabr 678-223-3900br br Many people confuse sacroiliac joint pain (SI) with low back pain. The SI joint is the junction between the sacrum and the bones of the pelvis (Ilium). The pain is felt around the buttocks and may feel like low back pain.br br If you've been diagnosed with SI joint pain or have pain below your belt line, the exercises in this video may help to alleviate some of your pain.