Abdominal MusclesMusclesRectus AbdominisDiaphragmElectromyographyRespiratory MusclesMuscle ContractionMuscle, SkeletalIntercostal NervesAbdominal WallMuscle ProteinsIntercostal MusclesAbdomenMuscle, SmoothRespiratory MechanicsPressureMuscle FatigueMuscle Fibers, SkeletalMuscle, Smooth, VascularRespirationPosturePositive-Pressure Respiration, IntrinsicInhalationNephropidaeMuscle DevelopmentAbdominal CavityLordosisThoraxLaryngeal MusclesMuscle RelaxationExhalationHypercapniaLumbosacral RegionIsometric ContractionCoughMuscle Fibers, Fast-TwitchMuscle DenervationPelvisMuscle Fibers, Slow-TwitchPulmonary VentilationBiomechanical PhenomenaMyocytes, Smooth MuscleLung Volume MeasurementsMitochondria, MusclePatient PositioningSupine PositionLow Back PainSpineAstacoideaElectric Stimulation