Electromyography (EMG) and nerve conduction velocity (NCV) are electrodiagnostic tests performed to measure the electrical activity of muscles and nerves.

EMG/NCV testing is the primary way to diagnosis diseases of the muscle and helps guide practitioners in selecting appropriate sites for biopsy when indicated.

These electrodiagnostic studies are typically prescribed to diagnose nervous system diseases including muscle (myopathy), nerve (neuropathy) and brain (encephalopathy).

Designed to diagnose any abnormality in the functioning of these nerves. These studies investigate the functioning of the nervous system, while imaging studies like CT scans or MRI scans look at the structure or anatomy of a body part or organ.

The NVC test helps differentiate between an injury to the nerve fiber and an injury to the myelin sheath, the protective covering surrounding the nerve. It can also help tell the difference between a nerve disorder and a condition where a nerve injury has affected the muscles.

An electromyography (EMG) test is often performed alongside an NCV test. An EMG test records the electrical signals moving through your muscles. This helps detect the presence, location, and extent of any disease that may damage the nerves and muscles.

Humans have described NCV tests as feeling like an electric static shock after walking across a carpet.  This lasts a very short time (1/1000 of a second).  EMG is measured with an ultra-thin, Teflon coated pin electrode to record muscle activity.  Because the wire is so thin, there is almost no risk of bleeding or infection.

Both tests carry low health risks with minimal discomfort to the patient.