Electromyography sends electrical signals through nerves to diagnose nerve problems. The electrogram (EMG) procedure is a test of your muscles and nerves. It consists of two parts: a nerve conduction study and a needle exam for muscle testing. The results can help your doctor find problems linked to certain disorders or conditions.
- The nerve conduction study involves stimulating the nerves at different points with small electric stimulation. This measures how well electricity moves through your nerves.
- The needle exam involves inserting very fine needles into several muscles. These needles pick up both normal and abnormal electrical signals given off by a muscle when you move them.
The electrogram procedure can provide information about the extent of nerve and/or muscle injury and can give some indication as to whether the damage is reversible. An electrogram procedure may be performed when patients have unexplained muscle weakness to distinguish if the problem is in the muscle or if it is due to nerve disorders. It can detect abnormal electrical activity of muscles and nerves that can occur in many diseases and conditions, including muscular dystrophy, muscle inflammation, pinched nerves, damage to nerves in the arms and legs (peripheral nerve damage) and carpal tunnel syndrome.
Watch this video to understand how electromyography works.