What is an EMG?

Electromyography (EMG) is a diagnostic test used to study nerve and muscle function and nerve conduction.


Why is an EMG performed?

The EMG study is conducted to determine if there is any disorder involving a muscle, the neuromuscular junction, or a nerve. Various types of nerve injury, muscle disease, and neurological conditions can be identified with this test.

This test is used to help evaluate the symptoms of pain, weakness, and numbness.


How is an EMG performed?

There is no special preparation for this test and you may take your usual medications. It is done in the office setting with the patient resting on an exam bed on either their back or chest.

First, a small pin attached to the EMG machine is inserted into the muscle being tested. The electrical activity of the muscle is then analyzed by listening to the sounds and by looking at the activity on the view screen of the EMG machine. The nerve conduction is measured using an electrical impulse. This causes the patient to experience a tingling sensation. The EMG machine records the path of the electrical impulse through electrodes placed on the skin of the area being tested.


What conditions are diagnosed by an EMG?

  • Pinched nerves to the neck and back: Cervical, thoracic, and lumbar radiculopathy
  • Carpal Tunnel Syndrome
  • Peripheral Neuropathies: Arthritis, lupus, rheumatoid arthritis, diabetes
  • Autoimmune Disease: Myasthenia Gravis
  • Inflammatory Myopathies
  • ALS/Lou Gehrig’s Disease