Inclusion Criteria:  Patients age 18 and older acute musculoskeletal pain initial pain score of 5 or more on a standard 11- point (0 to 10) numeric rating scale. awake, alert, and oriented to person, place, and time  Exclusion Criteria:  altered mental status, allergy to aspirin and ketamine, pregnant unstable vital signs (systolic blood pressure <90 or>180 mm Hg, pulse rate <50 or >150 beats/ min, and respiration rate <10 or >30 breaths/min) inability to provide consent consumption of Aspirin or NSAID's within 6 hours of arrival to the ED active PUD history of GI Hemorrhage history of renal and hepatic insufficiency past medical history of alcohol or drug abuse schizophrenia