When an inflammation occurs in the sacroiliac joints—the spot where the upper and lower halves of the body meet, where the spine connects to the pelvis and where body weight transfer is centered—the condition is known as sacroiliitis. Typically, sacroiliitis is result of an injury to the lower back or pelvis or from difficult pregnancies or childbirths (the joints loosen in order to make room for a fetus to emerge). Arthritis can also be the culprit for sacroiliitis, especially osteoarthritis.

Sacroiliitis typically presents as a pain in the lower back, buttocks or groin area. The pain sometimes radiated downward into the legs and feet, and often worsens with long periods of sitting or standing, running, climbing stairs and bending. And because the pain of sacroiliitis is similar to other causes of low back pain, it can be a complicated condition for a physician to diagnosis. When it is successful diagnosed, however, treatment takes the form of anti-inflammatory medications coupled with a ceasing of activities that can aggravate the condition, physical therapy and pain-relieving injections at the site of the affected area.