Background: F waves are low amplitude late responses due to antidromic activation of motor neurons following peripheral nerve stimulation. It is important in electro diagnosis as it can assess proximal and distal nerve segments unlike conventional nerve conduction studies. F wave minimal latency is the most important and frequently checked F wave parameter. F wave minimal latency is more in males comparing females in many studies.  Many authors explain this may be solely due the difference of height between male and female population as height is positively correlated with F wave minimal latency. But some other factors unique to males and females can also be reason of this difference.

Aim: Aim of this study was to study the effect of gender in F wave minimal latency independent of height.

Setting and Design: F wave study was done prospectively in 200 carefully screened healthy subjects of age group 20- 50 years. The study group included equal proportion of males and females. F wave minimal latencies of median and tibial nerves were found out.

Statistical Analysis Used: All statistical analyses were done with SPSS software version 16. F wave minimal latencies of median and tibial nerves were compared between male and female population using independent T test. Step wise linear regression analysis was done to find out the effect of gender independent of height. 

Result and Conclusion: Effect of gender on F wave minimal latency persisted even after nullifying the effect of height. The higher F wave minimal latency in males is not solely due to the difference in height. So gender wise reference data is to be used for proper interpretation of this electro diagnstic parameter

Keywords: F wave study, F wave, minimal latency, effect of gender, nerve conduction.

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Dr Rajalekshmi G

Professor, Department of Physiology,

Government Medical College, Idukki, Kerala, India