REFLEX TIME DURING GROWTH CONSIDERED IN RELATION TO INTERNODAL LENGTH AND CONDUCTION VELOCITY

Abstract

Measurements of latent period of a spinal reflex ("H reflex") were made on human subjects ranging in age from 6 to 42 years. Reflex time was found to vary directly with the size of the individual for the entire group investigated. It follows, therefore, that reflex time increases progressively during growth from the age of 6 years onward. The realtion between length of the internodal segment and velocity of impulse conduction is discussed in relation to available histological and physiological data. It is concluded that conduction velocity is proportional to fiber diameter and has no relation to internodal length.