Supine PositionSkullProne PositionHeadPosturePatient PositioningSkull BaseHead and Neck NeoplasmsSkull NeoplasmsSkull Base NeoplasmsSkull FracturesRange of Motion, ArticularHead MovementsTilt-Table TestBiomechanical PhenomenaMovementSupinationFemur HeadHead-Down TiltHeart RateKnee JointHypotension, OrthostaticGravitationSperm HeadNephrostomy, PercutaneousContractureCraniocerebral TraumaElectromyographyBlood PressureHead Injuries, ClosedRotationRespiratory MechanicsNeckLegTomography, X-Ray ComputedPressureSkull Fracture, DepressedFemur Head NecrosisHip JointAutonomic Nervous SystemValsalva ManeuverRespirationElbow JointTime FactorsWeight-BearingIndoraminSpineParietal BoneMuscle, SkeletalReference ValuesMagnetic Resonance ImagingSyncopeDizzinessBaroreflexNeck MusclesPelvisTorqueKneeSyncope, VasovagalArthrometry, ArticularHemodynamicsTreatment OutcomeReproducibility of ResultsCardiac OutputExpiratory Reserve VolumeImaging, Three-DimensionalTidal VolumePalate, SoftSudden Infant DeathProspective StudiesPulmonary Gas ExchangeOccipital BoneRibsRestArthroplasty, Replacement, KneeElbowFluid ShiftsKnee ProsthesisTechnetium Tc 99m Aggregated AlbuminCranial SuturesLumbar VertebraeCadaverCervical VertebraeEsophagusLung Volume MeasurementsEsophageal pH MonitoringPulmonary CirculationPharynxMolecular Sequence DataOxygenRetrospective StudiesBlood Flow VelocitySleepCephalometryThoracic WallEquipment DesignPosterior Cruciate LigamentCraniosynostosesSleep ParalysisAnalysis of Variance