NaproxenPainAnti-Inflammatory Agents, Non-SteroidalChronic PainPain ManagementPain ThresholdPain MeasurementPain, PostoperativeLow Back PainBack PainCyclooxygenase InhibitorsAbdominal PainIbuprofenNeck PainPain, IntractablePelvic PainPain PerceptionNaphthaleneacetic AcidsFacial PainEtodolacDiclofenacAcute PainPain, ReferredCyclooxygenase 2 InhibitorsSumatriptanAnalgesicsShoulder PainPiroxicamDouble-Blind MethodPhenylbutazoneMusculoskeletal PainThromboxane B2