Muscle ContractionMuscle, SkeletalTorqueIsotonic ContractionMuscle FatigueElectromyographyMuscle StrengthMusclesBiomechanical PhenomenaSarcomeresElectric StimulationHand StrengthMuscle RelaxationKneeRana temporariaMuscle Fibers, SkeletalElbowTime FactorsPsoas MusclesPhysical ExertionMyosinsMuscle Strength DynamometerPapillary MusclesExerciseMusculoskeletal Physiological PhenomenaPhysical EnduranceMyocardial ContractionVolitionRecruitment, NeurophysiologicalMyographyStress, MechanicalQuadriceps MuscleVasoconstrictionMovementCalciumMotor NeuronsRabbitsLegMuscle, SmoothElasticityRana esculentaKnee JointAnuraFingersTendonsAnkle JointThighMuscle, Smooth, VascularRange of Motion, ArticularArmModels, BiologicalPhosphocreatineMuscle TonusMuscle Fibers, Fast-TwitchHeart RateVasodilationVasoconstrictor AgentsAdenosine TriphosphateBlood PressureDose-Response Relationship, DrugElbow JointPotassium ChlorideAcetylcholinePhenylephrineMuscle SpindlesMuscle WeaknessHindlimbWeight-BearingTetanyAnalysis of VarianceMyosin Light ChainsHeartMuscle Fibers, Slow-TwitchKineticsLong QT SyndromeAorta, ThoracicReflex, StretchTracheaMotor CortexVasodilator AgentsEndothelium, VascularForearmEvoked Potentials, MotorAdaptation, PhysiologicalActomyosinThumbDogsPhosphatesWristRana pipiensDiaphragmRegional Blood FlowNorepinephrineAgingNeck MusclesRats, WistarArteriesHolothurinEnergy MetabolismMuscle Stretching Exercises