Quadriceps MuscleThighMuscle, SkeletalMusclesMuscle StrengthMuscle FatigueMuscle WeaknessMuscle ContractionTorqueIsometric ContractionKneeKnee JointFemoral NerveMuscle ProteinsMuscle Fibers, SkeletalMuscle Strength DynamometerElectromyographyElectric Stimulation TherapyPatellaLegExerciseMuscle, SmoothMuscular AtrophyMuscular DiseasesAnterior Cruciate LigamentBiomechanical PhenomenaKnee InjuriesPatellar LigamentMuscle, Smooth, VascularRespiratory MusclesMuscle Fibers, Slow-TwitchJoggingMuscle DevelopmentArtificial OrgansMitochondria, MusclePhysical EnduranceTendonsImmobilizationElectric StimulationOsteoarthritis, KneeOxygen ConsumptionPatellofemoral JointRange of Motion, ArticularMyostatinBicyclingWeight LiftingPhysical ExertionWeight-BearingJoint InstabilityMuscle Fibers, Fast-TwitchExercise TestGaitPatellofemoral Pain SyndromeArthroplasty, Replacement, KneeExercise TherapyMuscle DenervationRecovery of FunctionTime FactorsPulmonary Disease, Chronic ObstructiveMotor NeuronsAdaptation, PhysiologicalAbdominal MusclesLactic AcidMyocytes, Smooth MuscleMuscle SpindlesParaplegiaBiopsyRegional Blood FlowMuscle RelaxationGlycogenHypertrophyAnalysis of VarianceFemurNeck MusclesOculomotor MusclesMuscle, StriatedOrgan SizePainPain MeasurementPapillary MusclesMotor ActivityAgingHindlimbMagnetic Resonance ImagingMuscle CellsMasseter MuscleTreatment OutcomeFacial MusclesRuptureMasticatory MusclesPhysical Conditioning, HumanIntercostal MusclesOxygenMusculoskeletal Physiological PhenomenaDiaphragmH-ReflexPsoas MusclesSatellite Cells, Skeletal MuscleCase-Control StudiesMovement