Electromyography is often overrated as a research tool. I volunteered for
EMG tests during my stint at Nautilus. Then, I learned that they do indeed have some
value, but the caveats are that EMG interpretation is extremely limited when it is
performed ideally and probably worthless when performed otherwise.
Ideally, EMG requires the implantation of needle electrodes. Since this is an invasive
procedure, an MD is required. Only with needle electrodes can most dermal potential be
avoided and specific reading of the desired muscles be obtained. Surface electrodes used
by nonmedical researchers produce too much artifact (noise) to the monitor or graph
recorder.
Even with an MD competent with EMG, good needle placement, and state-of-the-art reception
and display equipment; EMG cannot be used to determine the intensity of muscular
contraction. It can, indeed, be sometimes used to distinguish between what muscles are
firing AND those that are not firing during a particular movement. Also, some physiatrists
use EMG to time nerve transmission speed and, hence, to determine aspects of nerve health.
I do not know if this is valid.
I have seen EMG pictured in some of the recent fitness magazines. I want members of the
Guild to recognize this as high-tech photographic appeal. It is not indicative of reliable
research data collection.