“…3,7,8 The role of the ligament in¯exion, extension, and lateral bending of the L5 on the sacrum has been con®rmed in di erent studies. 3,4,7,9 In Hirschberg's experience 1 the chronic ilio-lumbar syndrome is reported to be the most common cause of permanent or recurrent low back disability. In patients who are seen several weeks, months, or years after the onset of low back pain, the prognosis for complete recovery is not good.…”