NCS involve using a small electrical impulse, applied from an electrode over your skin, measured from point A to point B along the course of the tested nerve. Your doctor then measures the signal strength and time along the course of the nerve to help evaluate the proper functioning of the nerve or associated nerve roots.
EMG measures the electricity within a tested muscle. A small pin is inserted through the skin, into the muscle. The pin acts like a probe or microphone, helping the examiner measure the electric behavior of the muscle at rest and as it contracts. These tests measure how the nerves and muscles are working and can give your doctor complimentary information to other diagnostic studies.
To determine whether your nerves and muscles are working properly, your doctor may recommend you have electro-diagnostic (EDx) testing. This will usually consist of nerve conduction studies (NCS) and a needle electromyography (EMG) testing. Most testing takes about 45 minutes to an hour depending on how many studies are performed. Please do not wear any lotions or oils prior to your testing.