Isometric ContractionMuscle ContractionMuscle, SkeletalMusclesMuscle FatigueElectromyographyMuscle, SmoothMuscle Fibers, SkeletalIsotonic ContractionTorqueElectric StimulationMyocardial ContractionUterine ContractionMuscle, Smooth, VascularElbowMuscle RelaxationRecruitment, NeurophysiologicalBiomechanical PhenomenaMotor NeuronsCalciumMuscle ProteinsSarcomeresKneeMuscle StrengthMyosinsPapillary MusclesTime FactorsQuadriceps MusclePsoas MusclesVasoconstrictionPhysical EnduranceRabbitsMuscle SpindlesPhysical ExertionMusculoskeletal Physiological PhenomenaMyofibrilsVolitionGuinea PigsTracheaPotassium ChlorideMyographyElasticityRana temporariaMyosin Light ChainsMuscle DevelopmentPhenylephrineStress, MechanicalDose-Response Relationship, DrugAcetylcholineMuscle Fibers, Fast-TwitchHindlimbModels, BiologicalPhosphocreatineAdenosine TriphosphateRats, WistarTendonsLegThighCatsVasoconstrictor AgentsActinsMuscle Fibers, Slow-TwitchRats, Sprague-DawleyAction PotentialsAnkle JointMuscle WeaknessAnuraHand StrengthEvoked Potentials, MotorMovementMasseter MuscleReflex, StretchNorepinephrineFingersExerciseAorta, ThoracicMuscle Strength DynamometerHandMyocytes, Smooth MuscleDogsReflexPeristalsisRana esculentaMotor CortexMicroscopy, Atomic ForceArmMuscle TonusMuscle DenervationGastrointestinal MotilityElbow JointKineticsForearmAnalysis of VarianceEnergy MetabolismUrinary BladderNeck MusclesWeight-BearingAdaptation, PhysiologicalKnee JointMyocardium