Muscle ContractionIsometric ContractionMuscle, SkeletalMusclesMuscle Fibers, SkeletalMuscle FatigueMuscle ProteinsMuscle, SmoothTroponin CMyosinsElectric StimulationTroponinElectromyographyCalciumRabbitsMuscle, Smooth, VascularTropomyosinIsotonic ContractionTorqueMuscle RelaxationMuscle DevelopmentMyocardial ContractionRegional Blood FlowUterine ContractionMuscle Fibers, Fast-TwitchElbowMotor NeuronsRecruitment, NeurophysiologicalSarcomeresQuadriceps MuscleMuscle Fibers, Slow-TwitchPapillary MusclesBiomechanical PhenomenaTime FactorsMuscle SpindlesMyofibrilsMitochondria, MuscleKneePsoas MusclesMuscle StrengthPhysical EndurancePhysical ExertionMuscle DenervationVasoconstrictionHindlimbMuscle WeaknessMusculoskeletal Physiological PhenomenaMyocytes, Smooth MuscleGuinea PigsRats, WistarRana temporariaPhosphocreatineRats, Sprague-DawleyVolitionTracheaPotassium ChlorideAdenosine TriphosphateMasseter MuscleExerciseMuscular AtrophySatellite Cells, Skeletal MuscleStress, MechanicalLegMuscle, StriatedActinsDose-Response Relationship, DrugNeck MusclesAnuraAcetylcholineModels, BiologicalMyographyThighMuscle CellsMuscular DiseasesTendonsOculomotor MusclesMyosin Light ChainsPhenylephrineCatsAction PotentialsMyocardiumElasticityKineticsRespiratory MusclesAbdominal MusclesEnergy MetabolismVasoconstrictor AgentsDiaphragmReflex, StretchDogsNorepinephrineAnkle JointMuscle Strength DynamometerMyosin Heavy ChainsAgingOxygen ConsumptionGlycogenEvoked Potentials, MotorRana esculentaAorta, Thoracic