Ask The Expert: What Is The Sacroiliac Joint?

Authored by: VSI

One of the most common complaints we see in our clinic is the result of Sacroiliac (SI) Joint pain. There are two sacroiliac joints that connect with the pelvis and the lower part of the spine. Most joints, like the knee and hip, have a wide range of motion but the SI joint rotates and tilts only slightly. It’s limited rotation is actually beneficial in its role which is to stabilize and support the pelvis, helping to transmit the weight of the upper body to the legs and act as a “shock absorber” when walking or running.

The SI joint can be injured in a number of ways making even daily activities like sitting, walking, or climbing stairs difficult. This is called Sacroiliac Joint Dysfunction.


The most common cause of SI Joint Dysfunction can be traced back to a specific event, like an injury from a car accident or fall. Other times there is no obvious reason for the problem but could a result of any of these:

  • Sports injuries
  • Stress or injury to the joint over and over, such as from jogging
  • Older age
  • One leg that’s shorter than the other
  • A spinal injury
  • Scoliosis (abnormal curvature of the spine)
  • Spinal surgery, especially operations that fuse the lower part of the spine
  • Pregnancy
    • The hormones that a woman’s body makes near the time of delivery can cause the pelvis to relax and change position. Weight gain, changes in posture, and the childbirth process can also cause problems in the joint.


Pain is often the main symptom, usually in the lower back and buttock and sometimes the back and upper leg. Some people also feel SI joint pain in the groin, belly, or wrapping around from the back to the front of the thigh. The pain is often worst in the transition from sitting to standing or standing to sitting. Discomfort from SI joint dysfunction usually shows up on one side of the body rather than both sides.


VSI offers both non-operative and operative treatment options for SI joint pain including spinal injectionsregenerative medicine, and in some cases sacroiliac joint fusion. Lower back and leg pain could be the result of many conditions, so schedule an appointment with a doctor to figure out if your SI joint is really the cause of your discomfort.

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