Sacroiliac (SI) joint injections are used to alleviate pain stemming from swollen SI joints, two small joints located at the bottom of the spine. While they don’t produce much movement, these joints are significant. They absorb the downward force of the upper body and distribute the weight to the hips and legs. Irritated or inflamed SI joints can result in chronic pain in the lower back as well as other symptoms. Damage to this region cannot always be discovered through imaging techniques, so sacroiliac joint injections could be used as a diagnostic tool in addition to a therapeutic one.