During this test, your neurologist-technician inserts small electrodes into your muscles to help measure activity during periods of movement and rest. Such activity is recorded by a machine attached to the electrodes with a series of wires, which may be somewhat uncomfortable. Oftentimes, a neurologist will order a nerve conduction velocity (NCV) study in conjunction with an EMG. While an EMG measures muscle activity, an NCV assesses the ability of your nerves to send the necessary signals that control these muscles. If your neurologist recommends both tests, you’ll likely do the EMG first.