SpasmMyofascial Pain SyndromesMuscle SpasticityMusclesNeck MusclesSpasms, InfantileCervical AtlasOccipital BoneNeuromuscular AgentsMuscle ProteinsMuscle, SmoothMuscle, SkeletalSpinal Cord InjuriesMuscle, Smooth, VascularMuscle Fibers, SkeletalHemifacial SpasmMotor NeuronsBotulinum Toxins, Type AElectromyographyMuscle ContractionMuscle DevelopmentSciatic NerveMuscle FatigueMuscle Fibers, Fast-TwitchCoronary VasospasmMuscle Denervation