1. A machine used for producing a graphical tracing of the electrical activity picked up via electrodes inserted into muscle tissue which is used to diagnose muscular ailments.

It consists of an amplifier, an electrically activated trace-drawing pen, and a moving strip of paper.

2. An instrument which records differences in the electric potential of muscles that is used to diagnose muscular ailments.

Similar to the electrocardiograph, the electromyograph picks up clicks from sick muscles.