Compass is still being developed and is effectively in beta. Some content and features may be incomplete, change, or not work as expected.

Content is anchored to trusted sources where available, but Compass has not yet been clinically reviewed. It provides general information rather than medical advice.

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Tests and measurements

EMG

Electromyography

A test recording the electrical activity of muscles, using a fine needle placed into them.

What it means

A thin needle records the small electrical signals a muscle makes at rest and when you tense it. It shows whether the nerve supply to a muscle has changed, including in muscles that feel normal. Most people find it uncomfortable, and how long it takes varies.

Why you might hear it

  • It is one of the main tests used while reaching a diagnosis.
  • Results are read alongside the examination rather than on their own.

People who may help

Where Compass goes into this

About this explanation

These are plain explanations of words you may come across, not advice about your own situation. Where a word matters to a decision, the question pages go into it properly, and your own team is the place to take it.