BackIntermediate Back MusclesBack MusclesLumbosacral RegionSuperficial Back MusclesSpineLow Back PainMuscle, SkeletalMuscle FatigueMusclesElectromyographyAbdominal MusclesPostureMuscle ProteinsLumbar VertebraeBack PainMuscle, SmoothPostural BalanceProprioceptionMuscle Fibers, SkeletalMuscle, Smooth, VascularMuscle DevelopmentMuscle ContractionMuscle StrengthMuscle Fibers, Fast-TwitchMuscle DenervationMuscle Fibers, Slow-TwitchMyocytes, Smooth MuscleMitochondria, MuscleNeck MusclesOculomotor MusclesCervical VertebraeSpinal DiseasesMuscle, StriatedMuscle SpindlesMuscle WeaknessMuscle RelaxationRespiratory MusclesPapillary MusclesBack InjuriesQuadriceps MuscleMuscle CellsSpinal InjuriesMasseter MuscleFacial MusclesThoracic VertebraeMasticatory MusclesIntercostal MusclesMuscular AtrophyIsometric ContractionSatellite Cells, Skeletal MuscleDendritesPectoralis MusclesTime FactorsMuscular DiseasesSpinal FusionPsoas MusclesCells, CulturedCalciumElectric StimulationRabbitsMyofibrilsHindlimbRats, Sprague-DawleyTemporal MuscleBiomechanical PhenomenaSpinal FracturesSpinal NeoplasmsSynapsesMyosin Heavy ChainsIntervertebral DiscBone DensityActinsPharyngeal MusclesDiaphragmMotor NeuronsRats, WistarGlycogenNeuromuscular JunctionRNA, MessengerPain MeasurementMuscular Dystrophy, AnimalWeight-BearingMyoblastsMice, Inbred C57BLMovementModels, BiologicalZygapophyseal JointLegAgingMagnetic Resonance ImagingMuscle CrampSpinal CurvaturesSignal TransductionPhysical ExertionHippocampusMuscle RigidityExerciseLaminectomyRegeneration