Electromyography (EMG) is a technique for measuring, evaluating and recording the electrical activity produced by muscles. It is used to assess the health of muscles and their motor neurons, which are the nerve cells that control them. Motor neurons transmit electrical signals that cause muscles to contract. An EMG is performed using a medical instrument called an “electromyography” which detects the electrical signals generated by muscle cells when these cells are electrically or neurologically stimulated. An EMG translates these signals into graphs, sounds or numerical values that a specialist can interpret.
Your doctor may order an EMG if you have signs or symptoms that may indicate a nerve or muscle disorder. Such symptoms may include tingling, numbness, muscle weakness, muscle pain or cramping.
EMG results are often necessary to help diagnose or rule out a number of conditions including muscle disorders, diseases affecting the connection of the nerves and muscles, and peripheral nerve disorders, like carpal tunnel and peripheral neuropathies. EMG can also be used to detect disorders that affect the motor neurons in the brain, spinal cord or a pinched nerve from a herniated disc.
The results of the test are used as an aid for the doctor in his/her approach to formulate a thorough and comprehensive treatment plan for the patient.