Spinal Nerve RootsSpinal NervesPeripheral Nervous System NeoplasmsNerve Compression SyndromesSpinal CordLumbosacral RegionRadiculopathyLumbar VertebraeNeuralgiaMusclesSpinal Cord InjuriesInjections, SpinalMagnetic Resonance ImagingSciatic NerveSciaticaPeripheral Nerve InjuriesLigationPeripheral NervesLumbosacral PlexusGanglia, SpinalHyperalgesiaPeripheral Nervous System DiseasesNerve FibersCauda EquinaIntervertebral Disc DisplacementMuscle, SkeletalMuscle ProteinsMuscle, SmoothNerve BlockRats, Sprague-DawleySpinal CanalSpinal Cord NeoplasmsMuscle Fibers, SkeletalMuscle, Smooth, VascularCervical VertebraeSpinal StenosisPainPain MeasurementSacrumMuscle ContractionMyelographyMuscle DevelopmentPain ThresholdMotor NeuronsNerve RegenerationEpidural SpaceOptic NerveSpinal DiseasesSpinal Cord DiseasesLaminectomyCervical PlexusSpinal Cord CompressionNeurons, AfferentElectric StimulationRhizotomyMononeuropathiesLow Back PainPosterior Horn Cells