F-waves and conduction velocities range

A controversial aspect in F-wave studies is if these potentials are generated preferentially by large motoneuron or by motoneuron of all sizes. The purpose of this work is to compare the maximum and minimum conduction velocities of the fibers that generate the M-wave with the maximum and minimum conduction velocities of the F-waves elicited by ulnar nerve stimulation. There were no significant differences between maximum velocities. However, minimum F-wave velocity was significantly higher than minimum conduction velocity, suggesting that the F-waves registered were preferentially generated by the fastest conducting axons.