# Study of F-wave Components in a Control Population of Young Adults

## TL;DR

This study establishes normal F-wave values in young adults and finds that height strongly influences F-wave latency.

## Contribution

Provides normative data for rarely studied F-wave components and highlights the impact of height on latency.

## Key findings

- F-wave minimum latency strongly correlates with height across multiple nerves.
- Right side F-wave latency is significantly longer than the left side.
- Male participants show increased F-wave latency compared to females.

## Abstract

Introduction

The F-wave represents a delayed muscular response that occurs as a result of the antidromic activation of one or a few motoneurons ensuing the electrical stimulation of a peripheral nerve. F-wave response has various parameters, yet the primary application of F-waves is presently confined to latency measurement, with a particular emphasis on F-wave minimum latency. Our goal is to report F-wave data in a population of young healthy individuals, encompassing rarely examined components including F-wave/M-wave amplitude (F/M ratio), duration, chronodispersion, and persistence in both upper and lower extremity nerves.

Methods

F-response components were recorded from median, ulnar, tibial, and peroneal nerves in 100 healthy volunteers in the age group of 18-40 years. Linear regression analysis was conducted for the correlation of F-wave parameters with height and age. Gender comparison (unpaired t-test) and side-to-side comparison (paired t-test) were performed. A p-value of <0.05 was considered statistically significant.

Results

R2 values for the relationship of F-wave minimum latency with height for median, ulnar, tibial, and peroneal nerves were 0.755, 0.761, 0.739, and 0.650, respectively, suggesting a strong direct relation. F-wave minimum latency (mean value) increased by about 0.27±0.7 ms on the right side (as compared to the left) with statistical significance (p<0.001) (paired t-test) for the F-wave median study. Male participants had increased F-wave minimum latency: p<0.0001 and p<0.01 (unpaired t-test) for median (right and left sides, respectively) while p<0.05 for ulnar, tibial, and peroneal nerves (both sides). No other F-wave components exhibited significant variation in height, gender, and age.

Conclusion

The current research has established normal values for the various F-response components, including F-wave latencies, F-wave duration, F/M amplitude ratio, chronodispersion, and persistence in the young adult age group. Side difference reference values have also been established. A strong influence of height should be borne in mind during F-wave interpretation.

Reference values for the relatively scarcely studied F-wave component including F/M amplitude ratio, F-wave duration, F-wave persistence, and chronodispersion can be helpful in diversifying the clinical applicability of the F-response study.