The electromyogram (EMG) and Nerve Conduction Studies (NCS)

The term EMG is used in two slightly separate ways.

Firstly it is a category of test, which includes true EMG and nerve conduction studies. These two are often used together in the same patient. In this sense, EMG is used to distinguish these studies from EEG and EP which are performed for quite different types of illness.

Secondly, the electromyogram is a recording of the electrical activity of muscles. Electromyography is the process of recording the electromyogram. Both are abbreviated to EMG. Usually this is performed with a special EMG needle, which is quite small compared to most medical needles. EMG provides information about the muscles themselves and the nerves which drive them.

Nerve conduction studies are studies of the nerves. Small electrical pulses are used to stimulate the nerves and recordings are made of the responses. Felt pads or stick-on contacts are used to connect to the skin in most cases.

Many people find these tests peculiar and sometimes uncomfortable, but they are not usually too painful.