EMG’s are standard nerve conduction tests that are used to record the electrical activity of muscles. When muscles are active, they produce an electrical current. This current is usually proportional to the level of the muscle activity. EMG’s can be used to detect abnormal muscle electrical activity that can occur in many diseases and conditions, including inflammation of the muscles, pinched nerves, peripheral nerve damage ( damage of upper and lower arms and legs ).
An EMG is most often performed when patients have unexplained pain, numbness, tingling and muscle weakness. The EMG helps to distinguish between muscle conditions in which the problem begins in the muscle and muscle weakness due to nerve disorders. The EMG can also be used to detect true weakness, as opposed to weakness from reduced use because of pain or lack of motivation.
How you prepare Precautions The nervous system specialist (neurologist) conducting the EMG will need to know if you have certain medical conditions. Tell the neurologist and other EMG lab personnel if you:
Have a pacemaker or any other electrical medical device
Take blood-thinning medications
Have hemophilia, a blood-clotting disorder that causes prolonged bleeding
Questions to ask When you schedule your EMG, you may want to ask the following questions:
What time do I need to arrive?
Where is the EMG lab, and what's the best way to find it in the hospital or clinic?
Do I need to stop taking any prescription or over-the-counter medications before the exam?
Can a friend or relative be with me during the exam?
Bathing Take a shower or bath shortly before your exam to remove oils from your skin. Do not apply lotions or creams before the exam.