Isometric ContractionMuscle ContractionMuscle, SkeletalMusclesMuscle FatigueElectromyographyMuscle, SmoothMuscle Fibers, SkeletalIsotonic ContractionTorqueElectric StimulationMyocardial ContractionUterine ContractionMuscle, Smooth, VascularElbowMuscle RelaxationRecruitment, NeurophysiologicalMotor NeuronsMuscle ProteinsCalciumSarcomeresKneeBiomechanical PhenomenaMyosinsMuscle StrengthPapillary MusclesTime FactorsQuadriceps MuscleVasoconstrictionPsoas MusclesPhysical EnduranceMuscle SpindlesRabbitsPhysical ExertionMusculoskeletal Physiological PhenomenaMyofibrilsVolitionGuinea PigsTracheaPotassium ChlorideMyographyMuscle DevelopmentStress, MechanicalRana temporariaMuscle Fibers, Fast-TwitchPhenylephrineDose-Response Relationship, DrugLegAcetylcholineMyosin Light ChainsPhosphocreatineHindlimbAdenosine TriphosphateRats, WistarThighElasticityMuscle Fibers, Slow-TwitchTendonsVasoconstrictor AgentsCatsModels, BiologicalRats, Sprague-DawleyAction PotentialsAnkle JointAnuraMuscle WeaknessEvoked Potentials, MotorNorepinephrineActinsMasseter MuscleExerciseReflex, StretchAorta, ThoracicMuscle Strength DynamometerMyocytes, Smooth MuscleMovementCattleHand StrengthPeristalsisReflexDogsHandFingersMotor CortexRana esculentaMuscle DenervationGastrointestinal MotilityMuscle TonusArmForearmWeight-BearingElbow JointEnergy MetabolismUrinary BladderAnalysis of VarianceNeck MusclesCarbacholMuscle, StriatedMitochondria, MuscleHeart Rate