The purpose of this study is to evaluate the effectiveness and safety of cyclobenzaprine HCl 5 mg (muscle spasm medication) taken three times a day, alone or in combination with ibuprofen 400 mg or 800 mg (pain relief medication) taken three times a day, for the treatment of back or neck muscle pain with muscle spasm.

The objective of this multicenter, randomized, open-label, parallel-group, one-week study is to evaluate the effectiveness and safety of cyclobenzaprine HCl 5 mg three times a day for one week, alone or in combination with ibuprofen 400 mg or 800 mg taken three times a day, for acute back or neck muscle pain with muscle spasm. The primary measurement of efficacy is the subject-rated global impression of change after seven days of treatment, compared to baseline. Safety assessments during the study include the monitoring of adverse events, and a physical examination, assessment of vital signs and medical history of any present illnesses conducted during the baseline visit. The study hypothesis is that there will not be a statistically significant difference in patient ratings of global impression of change, muscle spasm, muscle pain, medication helpfulness, and functional ability, between the cyclobenzaprine HCl monotherapy group versus the cyclobenzaprine HCl/ibuprofen 400 mg and cyclobenzaprine HCl/ibuprofen 800 mg groups, for the treatment for acute back or neck muscle pain with spasm. Patients receive cyclobenzaprine HCl 5 mg administered orally three times a day for one week, or cyclobenzaprine HCl 5 mg with ibuprofen 400 mg administered orally three times a day for one week, or cyclobenzaprine HCl 5 mg with ibuprofen 800 mg administered orally three times a day for one week.

Inclusion Criteria:

• Experiencing neck or back pain for no more than 14 days
• Physician rating of the muscle spasm of the neck or back region as mild, moderate or severe
• Ability to discontinue all muscle relaxants, NSAIDs (anti-inflammatory drugs) and pain relievers, other than the study medications during the 7-day treatment period. (Cardioprotective doses of aspirin (<= 325 mg / day) may be taken.)

Exclusion Criteria:

• History of physician-diagnosed musculoskeletal neck or back muscle spasms within 12 months prior to the study
• neck or back pain radiating into the arms or legs
• history of serious medical conditions
• taken a narcotic or muscle relaxant within 12 hours of the baseline physician visit
• allergies to aspirin, NSAIDs or cyclobenzaprine HCl.