By inserting fine needles into your muscles and measuring the electrical
impulses, electromyography enables doctors to measure the activity
of various muscles - and it therefore helps them to decide which
nerves have been damaged. (When a nerve has been damaged the muscles
normally associated with that nerve will be less active than usual.)
Electromyography takes about half an hour and is fairly painless
and free of side effects.
Further information can be found at: