Supine PositionProne PositionPatient PositioningPostureBack PainLow Back PainBackTilt-Table TestHead-Down TiltHeart RateSupinationHypotension, OrthostaticNephrostomy, PercutaneousGravitationBlood PressureRespiratory MechanicsAutonomic Nervous SystemRespirationIndoraminValsalva ManeuverSyncopePressureMovementBaroreflexDizzinessHemodynamicsSyncope, VasovagalLegExpiratory Reserve VolumeCardiac OutputTidal VolumeSudden Infant DeathBack InjuriesPulmonary Gas ExchangeFluid ShiftsLung Volume MeasurementsPalate, SoftTechnetium Tc 99m Aggregated AlbuminEsophageal pH MonitoringEsophagusPulmonary CirculationHeadReference ValuesRestOxygenSleepTime FactorsThoracic WallSleep ParalysisFunctional Residual CapacityBlood Flow VelocityRibsSpineInhalationLungDiaphragmBedsAutonomic Nervous System DiseasesPharynxCarbon DioxidePelvisPlethysmographyVentilators, Negative-PressureAirway ResistanceMolecular Sequence DataCentral Venous PressureElectrocardiographyPneumoperitoneum, ArtificialRegional Blood FlowProspective StudiesLymphatic IrradiationEsophageal Motility DisordersVenous PressureTongueAirway ObstructionVeinsPulmonary VentilationRespiratory MusclesTotal Lung CapacityBlood VolumeSleep Apnea, ObstructiveAnesthesia, SpinalVascular ResistanceLumbar VertebraeReproducibility of ResultsNeckRespiration, ArtificialIntraocular PressurePolysomnographyTonometry, OcularExerciseOropharynxExercise TestJugular VeinsRespiratory Distress Syndrome, AdultBlood Gas AnalysisSnoringSphygmomanometersBiomechanical PhenomenaMagnetic Resonance Imaging