The level of the radial motor nerve injury can be determined in clinical diagnosis by the nerve conduction study as well as the neurological examination of the upper extremity.

The commonly used method of the radial nerve conduction study is the one that records from the extensor indicis proprius muscle among many other muscle groups, by inserting the needle electrode. However, the disadvantages of this method are, firstly, the uncertainty of the needle position because of the muscle's deep location, secondly, possible artifacts because of the inevitable needle movement, and, lastly, the severe pain for the patient. For such reasons, the authors aimed in this study to adopt the surface electrode clinically and have compared electrode group. The data were collected from 30 normal adults.

No significant difference was found in the distal latency and conduction velocity for the two group(p>0.05). The amplitude, however, was found to be significantly smaller(p<0.05) when using the surface electrode than the needle electrode although the value was greater than 5mV and acceptable for the nerve conduction study(p>0.05).

Furthermore, there was no significant difference between the right and left sides. When the radial nerve is suspected to be injured or entrapped, nerve conduction study using surface electrode can be a useful method as it is more convenient for the examiner and comfortable for the patient.