Pain ThresholdPainPain MeasurementSensory ThresholdsPain PerceptionTranscutaneous Electric Nerve StimulationPain ManagementHyperalgesiaChronic PainThermosensingPain, ReferredPain, PostoperativeAnalgesicsEar, ExternalDental Pulp TestAnalgesiaNociceptorsFibromyalgiaFacial PainLow Back PainHot TemperaturePressurePhysical StimulationNeck PainAcupuncture PointsAcupuncture AnalgesiaWristBack PainHypesthesiaMyofascial Pain SyndromesToothacheAnalgesics, OpioidSensationNociceptive PainNeuralgiaAbdominal PainAnalgesics, Non-NarcoticPain, IntractableDifferential ThresholdElectric Stimulation TherapyAuditory ThresholdPelvic PainAcupuncture TherapyHyperesthesiaElectroacupunctureSomatosensory DisordersElectric StimulationDouble-Blind Methodbeta-EndorphinAcute PainIrritable Bowel SyndromeCold TemperatureRadial NerveMorphineTemporomandibular Joint Dysfunction SyndromeSkin TemperatureAnalysis of VarianceVibrationWhiplash InjuriesLidocaineMigraine DisordersAnesthetics, LocalTime FactorsCross-Over StudiesShoulder PainChronic DiseaseMusculoskeletal PainSkin Physiological PhenomenaEvoked Potentials, SomatosensoryPerceptionTouchNAV1.7 Voltage-Gated Sodium ChannelSpinal CordPreanesthetic MedicationSkinNAV1.8 Voltage-Gated Sodium ChannelInjections, SpinalSensation DisordersRats, Sprague-DawleyThoracic WallBehavior, AnimalNAV1.9 Voltage-Gated Sodium ChannelPeriaqueductal GrayLasersAcetaminophenEndorphinsDiabetic NeuropathiesNaloxoneQuestionnairesTreatment OutcomePeripheral NervesReproducibility of ResultsNerve FibersRandom AllocationReaction TimeEdemaProspective StudiesDose-Response Relationship, DrugInjections, IntraventricularAnxiety