[Motor grammar of the spinal cord--status and revision]

Modern neurophysiological research, mainly in the second third of this century, has led to a set of widely accepted findings on the basic processes and rules of interactions between bodily periphery and the spinal level, which may be called a kind of elementary "grammar" of the spinal cord. As far as these apply to motor control functions, they are expressed here in condensed form as ten "paragraphs", which until recently belonged to the conventional standard teaching of neurophysiology. Each paragraph is then critically reviewed, supplemented and revised, as far as necessary, based on research progress in the last thirty years. The review deals with: Alpha motoneurones and their motor units; the muscle spindle with its sensory and motor structures, and its efferent controls by gamma and beta neurones; the spinal connections and effects of the afferents from primary and secondary spindle endings; properties and spinal effects of the Golgi tendon organs; new aspects of the flexor reflex afferents (FRA), of recurrent Renshaw feedback, and of presynaptic inhibition. The last paragraph stresses the importance of supraspinal controls of the spinal moto- and interneurones.