In preparing for electromyographic nerve testing, the subject should shower, avoid dermatological products, and bring shorts, a short-sleeved shirt and a list of medications currently used. If a blood-thinning medication or pyridostigmine is on that list, the patient should contact the testing facility, according to Noran Neurological Clinic.
If the subject bruises easily, has a pacemaker, has a skin infection or suffers from hemophilia, this should be told to the test conductor on arrival, claims Noran Neurological Clinic.
An EMG is used to quantify the electrical activity of a muscle. A needle called the electrode is inserted into the muscle where it detects the electric signal and sends it back to a monitor, where the amount of electrical activity is observed. The insertion of the electrode might induce slight pain, states Johns Hopkins Medicine.
The EMG test may last between 30 and 60 minutes. Some subjects experience sore muscles and tingling sensations for up to two days after the test. If the skin around the tested muscle swells or feels tender, the subject should call the doctor, according to WebMD.
An EMG can detect nervous system disorders when used properly, according to MedlinePlus. Symptoms of such disorders include weakness, pain or abnormal sensations.