Greater Sciatic Foramen Lumbar nerve roots combine to form the sciatic nerve. After exiting the spinal canal, the nerve travels through an opening in the pelvis called the greater sciatic foramen. Further Reading: Sciatic Nerve and Sciatica Related Articles What You Need to Know About SciaticaTypes of Sciatic Nerve PainSciatica Treatment Related Videos Sciatic Nerve Anatomy VideoWatch an animated video detailing the anatomy of the sciatic nerve. Sciatica Causes and Treatments VideoLearn about the possible causes of sciatica and the various treatment options such as medications, exercise, surgery, and steroid injections.Sciatica Animated VideoSciatica is leg pain caused by a problem in the low back. Watch an animated video that details the causes and symptoms of sciatica.