Electromyography uses special sensors to measure the electrical activity of the muscles and nerves in and around the bladder and the sphincters. If the health care provider thinks the urinary problem is related to nerve or muscle damage, the person may be given an electromyography. The sensors are placed on the skin near the urethra and rectum or on a urethral or rectal catheter. Muscle and nerve activity is recorded on a machine. The patterns of the nerve impulses show whether the messages sent to the bladder and sphincters are coordinated correctly. Electromyography is performed by a specially trained technician in a health care provider’s office, outpatient clinic, or hospital. Anesthesia is not needed if sensors are placed on the skin. Local anesthesia is needed if sensors are placed on a urethral or rectal catheter.