Some science behind the scenes

Electromyograph - EMG


Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles.  It is performed using an instrument called an electromyograph, to produce a record called an electromyogram.

An electromyograph detects the electrical potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect medical abnormalities, activation level, and recruitment order, or to analyze the biomechanics of human or animal movement.

There are some EMGs that work using a needle inserted in the skin, but the equipment that is more likely to be used in this context uses a surface electrode to monitor breathing muscles.  It is thus used to monitor the general picture of muscle activation, as opposed to the activity of only a few fibres as observed using an intramuscular EMG.

This machine is used clinically in a number of settings; for example, in the physiotherapy clinic, muscle activation is monitored using surface EMG and patients have an auditory or visual stimulus to help them know when they are activating the muscle.  The same approach can be used in controlled breathing exercises during training.


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