The sacroiliac (SI) joint and low back pain
Like any other joint in the body, the sacroiliac (SI) joint can degenerate or its supporting ligaments may be injured. When this happens, people can feel pain in their buttocks, lower back, groin and even in their legs. This is especially true with lifting, running, walking or even sleeping on the involved side.
It is important to note that on occasion, patients who have not had symptomatic relief from lumbar spine surgery may actually have had other issues to begin with. Pain in the lower back and buttocks may come from the SI joint, the hip, the spine, or a combination of these three interrelated potential pain generators.