This study will compare the efficacy of two different non-steroidal anti-inflammatory drugs (NSAIDs) ketorolac and ibuprofen for people with acute moderate or severe musculoskeletal pain. The investigators will also determine whether taking acetaminophen prior to the NSAID impacts efficacy

Inclusion Criteria:

• Acute musculoskeletal pain: Any pain attributable to muscles, bones, joints, tendons, ligaments or supporting structures, as determined by the clinical team, of 10 days duration or less. Prior to the onset of acute pain, patients cannot have experienced pain in the same body region during the prior six months
• Pain has to be described as moderate or severe, when the patient is asked if the pain is mild, moderate or severe in intensity

Exclusion Criteria:

• Contraindication to NSAIDs (allergy to NSAID or allergy to aspirin without history of tolerating NSAIDs, history of gastrointestinal bleeding, daily medication for gastritis or PUD, chronic kidney disease 2-5, heart failure)
• Contraindication to acetaminophen (hepatitis or cirrhosis)
• Use of an NSAID within the previous eight hours
• Use of acetaminophen within the previous eight hours
• Chronic pain, defined as any pain on >50% of days for at least 3 months prior to onset of acute pain
• Recurrent pain in the same body part as the presenting complaint

NSAID will be masked. Acetaminophen or no acetaminophen will not