Electromyography & Nerve Conduction Studies
To determine the cause of a patient’s pain and to develop the
proper course of treatment, a physician may order electromyography (EMG) and/or
nerve conduction studies (NCS).
These tests evaluate the peripheral nervous system by measuring
the electrical activity of muscles and nerves. They can help diagnose a
disorder of a patient’s muscles, nerves or both. These tests can be done
separately, but they are usually done at the same time.
An EMG test measures the
electrical activity of the muscles. NCS measure the speed and intensity of the
electrical signals that travel along a nerve and the time it takes for the
muscles to respond to this signal.
Muscles move when an
electrical impulse from the nerve causes them to relax or contract. When
injuries occur or when a patient suffers from a debilitating disease,
electrical impulses can be disrupted or slowed, causing pain, tingling or
An EMG or NCS can measure
this change in activity and the findings can be used to diagnose certain
conditions, including carpal tunnel syndrome, pinched nerves due to injury or a
ruptured disc, as well as other neuromuscular diseases and disorders.