Giving Santos™ Muscles: Electromyogram (EMG)
An electromyogram (EMG) is a test that is used to record the electrical activity of muscles. The EMG signal helps determine the activation timing of the muscles, which is when the excitation to the muscle begins and ends. The force produced by the muscle can also be estimated, along with the rate at which a muscle fatigues. The fatigue of a muscle is extremely complicated to determine, but can be approximated through the analysis of the frequency spectrum of the signal. To apply EMG data to Santos™, electrodes are attached to many people's muscles and measurements are taken as they carry out various types of motion, such as pointing to an object.
This EMG signal is used to determine when the muscle activity starts and stops and the amount of force each muscle produces, and, eventually, to determine when the muscle begins the fatigue state. This information will then be used when building and for understanding Santos's™ muscles as he performs specifi c tasks.
This readout describes the gastrocnemius muscle while a person was walking. Two electodes were attached to the back of the calf, and the ground electode was attached to the calf. The blue trace in the graph describes the electrical activity of the muscle during walking, and the red pulse represents a tendon tap, which stimulates a refl ex.
