Understanding the Basics of Electromyography (EMG)

Electromyography, more commonly referred to as EMG, is a powerful diagnostic tool used by medical professionals to evaluate the health and function of muscles and the nerves that control them. For patients experiencing unexplained muscle weakness, tingling, numbness, or nerve pain, an EMG can provide critical insights that guide treatment and improve outcomes.

At Arizona EMG, our mission is to provide patients with clarity about their condition, comfort during testing, and confidence in the results. In this article, we’ll walk you through everything you need to know about EMG testing—from what it is, to how it works, why it’s ordered, and what you can expect during the procedure.

An EMG (electromyography) measures the electrical activity of muscles both at rest and during contraction. When your muscles contract, tiny electrical signals travel from your nerves to your muscle fibers, triggering movement. If there is damage, compression, or disease affecting the nerves or muscles, those signals may be abnormal. EMG captures those signals and allows doctors to analyze them.

EMG is often performed alongside nerve conduction studies (NCS), which measure how quickly and effectively electrical impulses move along your nerves. Together, these tests provide a detailed picture of how well your nervous system is functioning.