[Conduction velocities of motor, cutaneous sensory, and IA proprioceptive fibers in normal newborn infant at term]

Abstract

Conduction velocities of non-nociceptive cutaneous and IA afferent fibres and alpha-motor fibres from ulnar, median, deep peroneal, posterior tibial and sural nerves have been measured in healthy full-term newborns, using surface electrodes. There is an overlapping in the distribution of the individual values of conduction velocities for the different types of fibres. The conduction velocities of cutaneous afferent fibres are not different in the upper or lower limbs. The conduction velocities of motor and IA fibres are higher in the upper than in the lower limb. In the upper limb, conduction velocities of IA fibres are higher than those of motor fibres, as they are in the lower limb for the posterior tibial nerve. Moreover, conduction velocities of motor fibres do not differ in males and females.