<qa>  What is the term for low back pain?Patients are included if their low back pain lasted less than one week, if they are 50 years old or younger, and if they had not experienced any direct trauma to the back during the previous week. Low back pain is described as pain originating below the tips of the scapulae and above the buttocks.Patients are only included if their straight leg raise test, as described below, is positive. Patients are excluded if the emergency physician felt that there is a high likelihood that the patient has a secondary cause of low back pain, e.g., metastatic bone disease or infection. Patients are also excluded for temperature greater than 100.3 degrees, pregnancy, lactation, allergy to or intolerance of a study medication. Patients can only enroll once. Patients can not have had another episode of back pain within four weeks prior to the current back pain attack. Patients are excluded for systemic steroid use within four weeks, a history of back surgery, a neoplasia known to metastasize, a chronic pain syndrome, an inflammatory arthritis, suspected vascular, urologic or gynecologic pathology, or direct blunt trauma to the back within the previous week. 