Nerve conduction studies are called EMG's, electromyograms. This study measures how well and how fast the nerves can send electrical impulses/signals. A needle electrode is inserted into a muscle after the skin over the muscle has been cleaned. The other end of the needle electrode is connected to a machine that records electrical activity. The person conducting the test, usually a neurologist, will ask the patient to perform certain tasks' such as moving a body part of squeezing their hand. All muscles in the body are controlled by nerves.
EMG's are done to help diagnose problems like a herniated disc, amyotrophic lateral sclerosis ALS, or myasthenia gravis. These diseases either damage the muscle tissue, the nerves, or the junction between the muscle and nerve. EMG's do not show brain or spinal cord diseases.