An electromyography (EMG) system is used to measure the electrical activity of muscles. The EMG system is composed of three parts: an electrode, an amplifier, and a display. The electrode is placed on the skin over the muscle to be tested. The amplifier increases the voltage of the signal coming from the electrode. The display shows the electrical activity of the muscle. The best EMG system for you depends on your needs. If you need to measure the electrical activity of a muscle, you need an EMG system with a good electrode and amplifier. If you need to measure the electrical activity of a muscle and nerves, you need an EMG system with a good electrode, amplifier, and display.