Electromyogram (EMG)

An electromyogram (EMG) – also known as a myogram - measures the electrical activity of muscles to determine the level of muscle activity. Since active muscles produce an electrical current, an EMG can detect abnormalities caused by diseases or conditions such as: herniated discs, muscular dystrophy, amyotrophic lateral sclerosis, myasthenia gravis, peripheral nerve damage and inflammation.

An EMG is often used to evaluate unexplained muscle weakness because it can:

• distinguish between a problem that began in the muscle and weakness due to a nerve disorder,
• pinpoint the level of a nerve injury,
• and differentiate between true weakness and weakness resulting from reduced use of the muscle.