1. Determination of the nature of a disease through observation of changes in electrical irritability.
2. The diagnosis of a disease or a dysfunction of the central and peripheral nervous systems and voluntary muscles by any method utilizing electrical stimulation or recording electrical activity.
3. Diagnosis of a disease or injury based on electrodiagnostic tests or procedures with electric stimulation of various nerves and muscles.

This technique is helpful in almost all branches of medicine; especially, when investigating the functions of the heart, the nerves, and the muscles.