What is the sacroiliac joint?
The sacroiliac joint is located on either side of the sacrum, which is in the low back and the pelvic areas. The SI joints are a pair of joints that connect the sacrum to the ilium, the large pelvic bone. Unlike other joints in the body, the surfaces of the SI joint are covered in two types of cartilage; one slick and the other spongy. The movement of the SI joint is minimal and results from stretching and is sometimes described as a gliding joint unlike the knee (hinge-type motion) or hip (ball and socket) joints.
