Introduction
Electromyography (EMG) is an electrodiagnostic test that evaluates the electrical activity of muscles during contraction and rest. Nerves communicate with the brain by sending nerve impulses, and healthy muscle function depends on this nerve input. EMGs are used by doctors to assess how muscles function in relation to nerve signals. This test is crucial for diagnosing conditions such as neuromuscular disorders, neurological diseases, muscle disorders, and nerve-related issues like pain or numbness.
Diagnosis
EMG is typically an outpatient procedure performed either in a doctor's office or a hospital setting. The test usually lasts between 30 and 60 minutes.
During the procedure, fine needle electrodes are inserted through the skin into the muscles controlled by a specific nerve. These electrodes capture the electrical activity of the muscle, both while at rest and during movement, and the data is recorded by a computer for analysis.
The doctor may need to adjust the electrodes at various points throughout the test to gather accurate readings from multiple muscles. While an EMG may cause some discomfort during the test, and slight muscle soreness may persist afterward, it is generally well-tolerated.
Often, EMG is performed alongside a nerve conduction velocity (NCV) test, which measures how fast electrical impulses travel through your nerves. The NCV test usually takes place before the EMG.
