o ascertain the norms and maturation of F-wave responses in early life

the velocities

latencies ampli-tudes and durations of F-waves at median

ulnar and tibial nerves in 150 normal children aged O-14 yearsold were analyzed as compared with the data of 20 young adults.F-waves could be elicited in any age

but the velocities at birth could only reach to 40%±of the values of adults

The velocities were developed as aFrunction in a close relationship with age or the length of extremities after birth.The level of adult wasreached during 6-14 or 3-6 years old for upper or lower extremities respectively wich was slower thanMCV for same motor nerve. It was presumblly related to the premature development of anterior horn cellswhich made a longer postpone-ment of central conduction of spinal cord in infants. The veliocities in upperextremity were faster than lower and also faster at proximate than distal recording

However the latencies of F-waves in all motor nerves as above inversely related to age and the length Of extremities significantly

and the amplitudes showed considerable variation individually

It can be concluded that as in adults

the F-wave responsis would also be a valuable clinical test in children to determine the functions of motor nerves

anterior horn cells and the roots of motor nerves.