The causes of lower back pain are often difficult to diagnose. One relatively common cause of lower back pain that seems to be overlooked is sacroiliac joint dysfunction.

Read more about Causes of Lower Back Pain

Watch: Sacroiliac Joint Dysfunction Video

The sacroiliac joint (also called the SI joint) connects the sacrum—the triangular shaped bone at the bottom of the spine—with the pelvis on each side of the spine.

See Sacroiliac Joint Anatomy

This joint is designed to provide stability and very little motion.

  • If it becomes unstable (too much motion), it can lead to lower back pain.
  • If it becomes too rigid (not enough motion), it can become a source of lower back pain.

In addition to lower back pain, sacroiliac joint problems may also cause pain in the hips or groin, as well as pain that radiates into the buttock and possibly down the path of the sciatic nerve (called sciatica, or lumbar radiculopathy).

See Sciatic Nerve and Sciatica


Accurately diagnosing sacroiliac joint dysfunction can be difficult because the symptoms mimic other common lumbar spine conditions, such as a lumbar disc herniation or lumbar degenerative disc disease.

Watch: Lumbar Herniated Disc Video and Lumbar Degenerative Disc Disease Video

Watch: Sacroiliac Joint Steroid Injection Video

How to get an accurate diagnosis

The structures in the spine are all interconnected, and determining the source of the pain is often quite difficult. In addition, degeneration in the sacroiliac joint does not mean that it is the cause of your pain. A recent review of CT scans of 373 adults showed that 65 percent had degeneration in their SI joints, but did not have any pain or other symptoms.1 This point applies to many lower back pain conditions; the MRI or CT scan may show degeneration, but that does not mean that the degeneration is the cause of your pain.

See Accurate Diagnosis of Sacroiliac Joint Dysfunction

One question that may be on your mind is: "Who is best qualified to diagnose a sacroiliac joint problem?" Many spine specialists are well qualified to make this diagnosis. Physiatrists, also called physical medicine and rehabilitation physicians, are well-qualified to provide both a diagnosis and rehabilitation of sacroiliac joint problems. Many physiatrists also have training and expertise in providing a sacroiliac joint injection, which is both a diagnostic tool and can provide pain relief.

See Sacroiliac Joint Injection for Lower Back Pain

Many chiropractors, physical therapists, and other spine specialists are also trained to evaluate whether the si joint is a source of pain.

The treatment options differ significantly depending on the underlying cause of your pain, so it is critical to get an accurate clinical diagnosis.

Treatment for sacroiliac joint dysfunction is usually non-surgical and focuses on physical therapy and rehabilitation to restore normal motion in the joint. For severe, chronic, disabling pain from SI joint dysfunction, surgery may be an option.

Learn more:

Treatment Options for Sacroiliac Joint Dysfunction

Stretches for Sacroiliac Joint Pain Relief