<qa>  What is the steroid injection?This is a randomized, double-blind placebo-controlled clinical trial evaluating intramuscular methylprednisolone acetate as adjunctive therapy for radicular low back pain. This trial randomizes subjects after they had been evaluated and treated in the ED and are ready for discharge. All subjects are followed by telephone call one week and one month after ED discharge. In addition to the steroid injection, all subjects are given a complimentary one week supply of naproxen 500 mg tablets and oxycodone 5mg acetaminophen 325 tablets and a detailed low back pain instruction sheet. This study was approved by the Montefiore Medical Center institutional review board. 