EMG; Myogram
Muscle tissue is normally electrically silent at rest. Once the muscles quiet down after the needles are inserted, there should be little muscle cell electrical activity noted on the screen.
When the muscle is voluntarily contracted, activity begins to appear. As contraction is increased, more and more muscle fibers produce action potentials until a disorderly group of action potentials of varying rates and amplitudes (complete recruitment and interference pattern) appears with full contraction.
Disorders or conditions that cause abnormal results include the following: