This syndrome is characterized by the acute onset of pain during torsional strain, tenderness over the affected joint, and relief of symptoms by infiltration of the joint with a local anesthetic.

The most frequent causes of low back pain are muscle and ligament strains, disk disease and arthritis. One relatively uncommon disorder sometimes overlooked in the differential diagnosis of low back pain is sacroiliac sprain syndrome.

The sacroiliac joints are among the strongest in the human body. These...