Muscle ContractionMuscle, SkeletalTorqueIsotonic ContractionMuscle FatigueElectromyographyMuscle StrengthMusclesBiomechanical PhenomenaHand StrengthElectric StimulationSarcomeresMuscle RelaxationKneeRana temporariaMuscle Fibers, SkeletalElbowPsoas MusclesPhysical ExertionMuscle Strength DynamometerMyosinsTime FactorsPapillary MusclesExerciseMusculoskeletal Physiological PhenomenaVolitionPhysical EnduranceMyocardial ContractionRecruitment, NeurophysiologicalStress, MechanicalMyographyQuadriceps MuscleMovementCalciumVasoconstrictionMotor NeuronsRabbitsElasticityFingersLegMuscle, SmoothKnee JointRana esculentaAnuraTendonsAnkle JointModels, BiologicalArmMuscle, Smooth, VascularThighPhosphocreatineRange of Motion, ArticularMuscle TonusMuscle Fibers, Fast-TwitchVasoconstrictor AgentsVasodilationHeart RateMuscle SpindlesAdenosine TriphosphateBlood PressureElbow JointPhenylephrinePotassium ChlorideAcetylcholineDose-Response Relationship, DrugMuscle WeaknessWeight-BearingTetanyHindlimbAnalysis of VarianceMyosin Light ChainsMotor CortexMuscle Fibers, Slow-TwitchEvoked Potentials, MotorEndothelium, VascularAorta, ThoracicHeartVasodilator AgentsWristTracheaReflex, StretchForearmActomyosinAdaptation, PhysiologicalRegional Blood FlowDiaphragmDogsThumbAgingRana pipiensNorepinephrineArteriesKineticsHolothurinPhosphatesNeck MusclesMuscle Stretching ExercisesEnergy MetabolismPostureRats, Wistar