Mesh : Adult Age Factors Brain Diseases / diagnosis Child Child, Preschool Electric Stimulation Electrodes H-Reflex Humans Infant Infant, Newborn Motor Neurons / physiology Muscles / innervation Neurons, Afferent / physiology Neurons, Efferent / physiology Reflex, Monosynaptic Sacrococcygeal Region / innervation Tibial Nerve / physiology Time Factors