Quadriceps MuscleMuscle, SkeletalMusclesMuscle WeaknessElectromyographyPolymyositisThighMuscular DiseasesMuscle FatigueMuscle ContractionMyositisMuscle ProteinsMuscular AtrophyMuscle StrengthMuscle Fibers, SkeletalMuscle, SmoothIsometric ContractionTorqueMuscle, Smooth, VascularDermatomyositisBiomechanical PhenomenaKneeKnee JointFemoral NerveMuscular Dystrophies, Limb-GirdleMuscle DevelopmentMuscle Strength DynamometerForelimbArmMuscle Fibers, Slow-TwitchElectric Stimulation TherapyRespiratory MusclesMitochondria, MuscleExercisePatellaLegCreatine KinaseMuscle Fibers, Fast-TwitchBiopsyMuscle DenervationMotor CortexNeural ConductionAnterior Cruciate LigamentKnee InjuriesPatellar LigamentMyocytes, Smooth MuscleElectric StimulationTendonsJoggingMuscle SpindlesPhysical EnduranceNeck MusclesOculomotor MusclesImmobilizationMuscle RelaxationArtificial OrgansAbdominal MusclesMuscle, StriatedMyostatinOxygen ConsumptionPhysical ExertionPapillary MusclesOsteoarthritis, KneeWeight LiftingPatellofemoral JointWeight-BearingBicyclingRange of Motion, ArticularTime FactorsPedigreeJoint InstabilityMuscle CellsMotor NeuronsExercise TestGaitMasseter MuscleFacial MusclesMasticatory MusclesIntercostal MusclesGlycogenPatellofemoral Pain SyndromeExercise TherapyAdaptation, PhysiologicalArthroplasty, Replacement, KneeHypertrophyLactic AcidPulmonary Disease, Chronic ObstructiveSatellite Cells, Skeletal MuscleRecovery of FunctionPectoralis MusclesRegional Blood FlowHindlimbOrgan SizeAnalysis of VarianceMyofibrilsParaplegiaAgingDiaphragmMyosin Heavy ChainsPsoas Muscles