I have had them done.

the emg is a machine that nerve conduction.  They put a little machine with wires on you and
test different nerves in your legs and arms. If you react and the machine measure then it is
fine. The machine can determine if you have damage to the nerve itself.

http://www.nlm.nih.gov/medlineplus/ency/article/003929.htm

http://www.emedicinehealth.com/electromyography_emg/article_em.htm

there you go, read those and it helps you to understand

janers

Hi Trouble, I've had 2 full body nerve conduction studies (not pleasant but
not as bad as I had anticipated) because they suspected MS. An MRI showed an
occipital area of attenuation, most likely from lupus. Anyway, the reason
for TWO is because my doc's secretary 'lost' the 1st results. Needless to
say, I was extremely PO'd, especially given that this woman was NOT the most
personable human on the planet. It's not as bad as you may be fearing.

Candi