Supine PositionUpper ExtremityFluid ShiftsProne PositionPostureShoulder PainPostural BalanceArmBiomechanical PhenomenaAbdomenNeck PainBody CompositionAdipose TissueMuscle StrengthPatient PositioningRegional Blood FlowGaitPhysical FitnessMuscle, SkeletalExerciseMovementWalkingObesityAnthropometryOxygen ConsumptionElectromyographyReference ValuesProspective StudiesSupinationBody Mass IndexHypotension, OrthostaticTilt-Table TestUpper Gastrointestinal TractGravitationHeart RateHead-Down TiltBlood PressureHypergravityRespiratory MechanicsNephrostomy, PercutaneousAutonomic Nervous SystemRespirationValsalva ManeuverDizzinessBaroreflexEsophagusFunctional Residual CapacityHemodynamicsAutonomic Nervous System DiseasesPulmonary CirculationShy-Drager SyndromeAirway ObstructionPalate, SoftPressureRestLegBed RestPulmonary Gas ExchangeLower Body Negative PressureLung Volume MeasurementsCardiac OutputSyncopeSpace FlightAirway ResistanceTime FactorsWeightlessnessPhysical ExertionPure Autonomic FailureTidal VolumeSyncope, VasovagalInhalationSleepLungExercise TestDiaphragmSudden Infant DeathTongueSympathetic Nervous SystemForearmGastrointestinal HemorrhageBones of Upper ExtremityRespiratory Physiological PhenomenaThoracic WallPharyngeal MusclesColonography, Computed TomographicThoraxPharynxAir PressureTomography, X-Ray ComputedReproducibility of ResultsVascular ResistanceWeightlessness SimulationElectrocardiographyHypopharynxBlood Flow VelocityRibsLarynxPlethysmographyBlood VolumePulmonary Ventilation