Introduction: Tibial F-wave recordings are remarkable for their complexity and persistence. We postulate that the signal recorded by the E2 (reference) electrode causes this pattern.
Methods: Tibial F-wave recordings were made from the abductor hallucis (AH) muscle using the standard montage in 10 subjects. Additional far-field simultaneous F-wave recordings were made from the AH, the base of the large toe, and the base of the small toe with the E2 placed on the contralateral foot.
Results: F-wave recordings made in the standard manner and from the base of the large or small toes showed complex waveforms and similar latencies. Recordings made from the AH-contralateral foot had simple waveforms in most subjects; in 2 subjects the latencies were longer, and 1 showed reduced persistence.
Conclusions: The tibial F-waves are composed primarily of volume conducted recordings of the tibial-innervated foot muscles from the E2 electrode.
Keywords: A-wave; F-wave persistence; F-waves; far-field recordings; tibial nerve.
© 2015 Wiley Periodicals, Inc.