Supine PositionSkullProne PositionPosturePatient PositioningSkull BaseHeadMusclesSkull NeoplasmsSkull Base NeoplasmsSkull FracturesMuscle, SkeletalMuscle ProteinsMuscle, SmoothMuscle Fibers, SkeletalMuscle, Smooth, VascularHead and Neck NeoplasmsTilt-Table TestMuscle ContractionMuscle DevelopmentHead-Down TiltHeart RateSupinationHypotension, OrthostaticRespiratory MusclesMuscle FatigueMuscle Fibers, Fast-TwitchGravitationBlood PressureMuscle DenervationNephrostomy, PercutaneousNeck MusclesHead MovementsMuscle Fibers, Slow-TwitchRespiratory MechanicsMovementTime FactorsMyocytes, Smooth MuscleMitochondria, MuscleOculomotor MusclesRespirationLegElectromyographySkull Fracture, DepressedAutonomic Nervous SystemPressureDiaphragmBiomechanical PhenomenaMuscle SpindlesMuscle, StriatedValsalva ManeuverIndoraminFemur HeadTomography, X-Ray ComputedMasticatory MusclesMuscle RelaxationAbdominal MusclesParietal BoneBaroreflexMuscle WeaknessSyncopePapillary MusclesReference ValuesHemodynamicsMolecular Sequence DataDizzinessCardiac OutputSyncope, VasovagalOxygenTidal VolumePulmonary Gas ExchangeRestMasseter MuscleRegional Blood FlowExpiratory Reserve VolumeEsophagusQuadriceps MuscleMagnetic Resonance ImagingMuscle CellsExerciseSudden Infant DeathCraniocerebral TraumaRibsIntercostal MusclesFacial MusclesLung Volume MeasurementsFluid ShiftsPalate, SoftNeckInhalationIsometric ContractionPharynxCranial SuturesPulmonary CirculationTongueTechnetium Tc 99m Aggregated AlbuminBlood Flow VelocityEsophageal pH MonitoringLungPhysical Exertion