Muscle ContractionMuscle, SkeletalTorqueIsotonic ContractionMuscle FatigueElectromyographyBiomechanical PhenomenaMuscle StrengthMusclesHand StrengthElectric StimulationKneeStress, MechanicalSarcomeresMuscle RelaxationMuscle Fibers, SkeletalElbowRana temporariaMuscle SpindlesPhysical ExertionTime FactorsMovementExercisePsoas MusclesMyosinsMuscle Strength DynamometerVolitionPhysical EndurancePapillary MusclesMotor NeuronsElasticityMusculoskeletal Physiological PhenomenaMotor Neurons, GammaMyocardial ContractionFingersKnee JointRecruitment, NeurophysiologicalLegMyographyVasoconstrictionQuadriceps MuscleCalciumTendonsRange of Motion, ArticularRabbitsModels, BiologicalCatsMuscle, SmoothAnkle JointWeight-BearingArmAnuraPostureHeart RateThighRana esculentaMuscle Stretching ExercisesBlood PressureReflex, StretchHindlimbElbow JointReflexMuscle TonusMuscle, Smooth, VascularAnalysis of VariancePressurePhosphocreatineMuscle Fibers, Fast-TwitchAdaptation, PhysiologicalAdenosine TriphosphateVasoconstrictor AgentsVasodilationMuscle WeaknessPhenylephrinePostural BalanceDose-Response Relationship, DrugEndothelium, VascularPotassium ChlorideAcetylcholineForearmRegional Blood FlowTetanyKineticsThumbNeck MusclesEvoked Potentials, MotorAorta, ThoracicFootHeartMotor CortexDiaphragmMyosin Light ChainsTracheaWristAction PotentialsMuscle Fibers, Slow-TwitchDogsAgingAchilles TendonTemperature