Skip to content

The Sacroiliac Joint: What is it and What Does it Do?

If you stand up from your chair and feel a pain in your lower back, it could be your sacroiliac joint (SI joint) acting up. So, what exactly is a sacroiliac joint and what does it do?

Sacroiliac Joint

The sacroiliac joint connects the sacrum (triangular bone at the bottom of the spine) with the pelvis (iliac bone that is part of the hip joint) on each side of the lower spine. It transmits all the forces of the upper body to the pelvis and legs. There is not a lot of motion in the joint and it is very strong and stable. It is not totally understood why sacroiliac joint dysfunction occurs, although some believe it is due to a limitation in its normal motion patterns and/or misalignment of the joint. Sacroiliac joint pain typically results in pain on one side very low in the back or in the buttocks. Another term for sacroiliac joint pain is sacroiliitis, a term that describes inflammation in the joint.

Sacroiliac Joint Pain

Mechanical strain and injury to the sacroiliac joint are produced by either a combination of vertical compression and rapid rotation (i.e. carrying a heavy object and twisting), or by falls on the backside. Injuries of this type can produce ligamentous laxity and allow painful abnormal motion. Instability can also arise from lumbar spine surgery in which a large portion of the iliolumbar ligament is injured. SI joint pain can also be caused by leg length discrepancy, gait abnormalities, prolonged, vigorous exercise, trauma, traumatic birth, and long scoliosis fusions to the sacrum. Painful sacroiliac joint arthritis can also arise from autoimmune disorders, such as ankylosing spondylitis, juvenile rheumatoid arthritis, Reiter’s Syndrome, psoriatic arthritis, and infections including staphylococcus, gonorrhea and TB.


Treatment for sacroiliac joint pain is most commonly non-surgical and is generally focused on reducing inflammation and pain and restoring normal motion in the joint. Non-surgical treatment may include one or a combination of the following:

  • Chiropractic Care
  • Physical Therapy and/or Exercise
  • Pain Medications
  • Injections to SI Joint
  • Use of a Pelvic Belt

If you or a loved one is suffering from sacroiliac joint pain, we’d love to help. Contact us today to set up an appointment!

Add Your Comment (Get a Gravatar)

Your Name


Your email address will not be published. Required fields are marked *.