Isometric ContractionMuscle ContractionMuscle, SkeletalMusclesMuscle FatigueElectromyographyMuscle, SmoothMuscle Fibers, SkeletalIsotonic ContractionTorqueElectric StimulationMyocardial ContractionUterine ContractionMuscle, Smooth, VascularElbowMuscle RelaxationRecruitment, NeurophysiologicalMotor NeuronsMuscle ProteinsCalciumSarcomeresKneeBiomechanical PhenomenaMyosinsMuscle StrengthPapillary MusclesTime FactorsQuadriceps MuscleVasoconstrictionPsoas MusclesPhysical EnduranceRabbitsMuscle SpindlesPhysical ExertionMusculoskeletal Physiological PhenomenaMyofibrilsVolitionGuinea PigsTracheaPotassium ChlorideMyographyMuscle DevelopmentDose-Response Relationship, DrugStress, MechanicalPhenylephrineRana temporariaMuscle Fibers, Fast-TwitchAcetylcholineMyosin Light ChainsPhosphocreatineHindlimbRats, WistarAdenosine TriphosphateLegElasticityThighModels, BiologicalCatsMuscle Fibers, Slow-TwitchVasoconstrictor AgentsRats, Sprague-DawleyTendonsAction PotentialsEvoked Potentials, MotorAnuraAnkle JointMuscle WeaknessExerciseNorepinephrineMasseter MuscleReflex, StretchAorta, ThoracicMuscle Strength DynamometerDogsMovementMyocytes, Smooth MuscleHand StrengthReflexHandPeristalsisFingersMotor CortexRana esculentaMuscle DenervationGastrointestinal MotilityForearmMuscle TonusArmWeight-BearingEnergy MetabolismElbow JointUrinary BladderAnalysis of VarianceNeck MusclesKineticsHeart RateMuscle, StriatedCarbacholMitochondria, MuscleAdaptation, Physiological