Electromyography (EMG)


What is an EMG?

An EMG is a special test that is used to study how your nerves and muscles are working. It is often required if you are complaining of symptoms of pain, numbness, tingling or weakness in the arms and legs.

What does EMG involve?

It is actually made up of two different tests, though you may not necessarily need to have both done:

1. Nerve conduction studies –

  • The ability of nerves to carry electrical signals to the brain is studied.
  • Nerves are a bit like electrical cables, they carry signals in the form of electrical pulses to and from the brain. In nerve conduction studies we excite the nerves using small electrical pulses and study the responses.
  • These can provide us with information on how the nerves are working and whether there are any blockages (i.e. a carpal tunnel syndrome).
  • The test does entail you receiving small electrical pulses. These are generally not painful but it can be an unusual sensation. We do however try to keep the number of pulses to a minimum.

2. EMG (electromyography) –

  • In this test the electrical activity of the muscles is studied.
  • This can provide additional information about the workings of the nerves and muscles that nerve conduction studies alone cannot provide.
  • A very fine electrode is inserted into the muscles to record their electrical activity.
  • This is generally well tolerated but you must tell your doctor however if you are taking Warfarin as this can influence whether the test is done.