Avoid using any creams or lotions on the day of the test.Typically, not a lot of preparation is necessary for an EMG. An NCV helps to differentiate a nerve disorder from a muscle disorder. The electrode will detect electrical activity and results will be displayed on a nearby monitor (oscilloscope).Ī nerve conduction velocity (NCV) test is often performed at the same time as an EMG. Once the electrode is in place, the patient will be asked to either contract their muscles or keep their muscles relaxed. How is an EMG performed?Ī very thin needle (electrode) will be inserted through the skin and into the muscle. Electromyography (EMG) is a diagnostic test that helps detect neuromuscular abnormalities by measuring electrical activity in the muscles.