Lumbar Spinal Discs L4, L5, and S1 The majority of sciatica symptoms result from lower back disorders between L4 and S1. These disorders cause pressure on or irritation to the lumbar nerve root. Further Reading: What You Need to Know About Sciatica Related Articles Sciatica CausesSciatica TreatmentLower Back Pain Symptoms and Causes Related Videos 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. Causes of Lower Back Pain VideoChronic pain in the lower back may be caused by the discs or the joints of the spine.