Your nerves and muscles send electrical signals to your brain, but if you have an illness or are injured, those messages could slow down or stop. By doing electrodiagnostic testing, which is administered by a physician that has received specialized training during their residency or fellowship, your health professional can analyze the activity in your muscles to find out how the nerves in your arms and legs are working, and how fast (or slow) the electrical impulses move along your nerve. During the EMG portion of the testing, several small needles will be placed in your muscle, and a small electrical current will be sent to stimulate your nerves. The doctor will watch the electrical signals that are transmitted on a small screen. You will be asked to relax and tense your muscles, while your doctor analyzes the results. The test generally isn’t painful, but you may feel mild discomfort. The testing will determine the location, severity, and assist with prognosis of nerve injuries or related conditions that you may have so that the most appropriate treatment can be recommended for you. Electrodiagnostic testing is often used to diagnose carpal tunnel, pinched nerves or other suspected nerve conditions.