Muscle TonusMuscle HypertoniaGaitGait Disorders, NeurologicMusclesMuscle, SmoothMuscle ContractionMuscle ProteinsMuscle, SkeletalNeck MusclesMuscle Fibers, SkeletalMuscle, Smooth, VascularGait AtaxiaMuscle DevelopmentAutonomic Nervous SystemParasympathetic Nervous SystemGait ApraxiaBiomechanical PhenomenaWalkingMuscle FatigueMuscle Fibers, Fast-TwitchMuscle Denervation