Lumbar Radiculopathy (sciatica) is lower back pain that radiates down into the legs along a specific nerve pattern. The most common cause of lumbar radiculopathy is a herniated disc causing compression on the lower spine nerve roots. These nerves innervate the legs along specific patterns called dermatomes. The pain can also be characterized by a burning, tingling, numbness and a pins and needles sensation. Lumbar epidural steroid injections are used to treat lumbar radiculopathy.