Prior to 1934, when lumbar disc herniation was discovered, the sacroiliac joint was thought to be the major source of low back pain. About that time, concern was diverted to surgical remedies for discs which, although providing dramatic relief in some cases, have proven to be limited in relieving many low back complaints. With the recent emergence of biomechanical science, the sacroiliac joints are again considered to play a pivotal role in the total musculoskeletal complex.