Muscle, SkeletalMusclesMuscle ContractionMuscle Fibers, Slow-TwitchMuscle Fibers, Fast-TwitchHindlimb SuspensionMuscle Fibers, SkeletalMuscle DenervationMuscle ProteinsMuscular AtrophyHindlimbMuscle FatigueMuscle DevelopmentElectromyographyH-ReflexIsometric ContractionMuscle, SmoothMyosin Heavy ChainsMitochondria, MuscleMuscle SpindlesRats, WistarMuscle, Smooth, VascularElectric StimulationGlycogenMotor NeuronsPhysical Conditioning, AnimalAnkle JointCatsImmobilizationTendonsLegRats, Sprague-DawleyOrgan SizeTarsus, AnimalMyofibrilsBiomechanical PhenomenaTime FactorsClenbuterolAnklePhysical ExertionBody WeightMuscle WeaknessTibial NerveInsulinReflex, StretchAchilles TendonRats, Inbred StrainsNeuromuscular JunctionMuscular Disorders, AtrophicMuscular DiseasesMuscle RelaxationCitrate (si)-SynthaseRunningMyostatinGlucoseReflex, MonosynapticPhosphocreatineMotor Neurons, GammaMyocytes, Smooth MuscleAdaptation, PhysiologicalTorqueSatellite Cells, Skeletal MuscleIsotonic ContractionWeightlessnessAgingRegenerationRNA, MessengerQuadriceps MuscleRats, Inbred F344LocomotionPhysical EnduranceWeight-BearingDiaphragmSarcomeresNeural ConductionNeck MusclesOculomotor MusclesHistocytochemistryGlucose Transporter Type 4Muscular Dystrophy, AnimalEquinus DeformityMuscle Stretching ExercisesMuscle, StriatedSpace FlightNeurons, AfferentFootHypertrophyLactic AcidSciatic NerveRespiratory MusclesVibrationPapillary MusclesPostureDeoxyglucoseStress, MechanicalCalciumSarcolemmaRabbitsProtein IsoformsMuscle Cells