The F wave has been thought to be useful in assessing the proximal neuropathy such as radiculopathy. However the sensitivity of F wave in radiculopathy is varying from 18% to 65%. The aim of this study is to compare the relative diagnostic value of 20 averaging technique and 20 sequential stimulation technique in recording the F waves and to determine the usefulness of F wave for the evaluation of radiculopathy.

Animals employed were rabbits that were divided into a study group of 17 rabbits(31 legs) and control group of 14 rabbits(25 legs). In the study group, the sciatic nerve was exposed after the dissection of gluteus maximus muscle and the nerve trunk was traced up to reach the spinal canal level. One of the two nerve roots composing the sciatic nerve was dissected randomly. F wave parameters were measured using both of 20 averaging technique and 20 sequential stimulation technique.

The parameters which showed significant change after the root dissection were the amplitude by employing 20 electronic averaging technique, and mean latency, minimal latency, mean amplitude by employing 20 sequential stimulation technique.

We concluded that 20 electronic averaging technique had no benefit over the 20 sequential stimulation technique and F wave measurement was not useful for the electrodiagnosis of radiculopathy because of the wide range of control values.