A myoelectric prosthesis is an externally powered prosthesis that uses the existing muscles in your limb to control the functions of your prosthesis. One or more sensors embedded in your socket pick up electrical signals as you activate underlying muscles. These signals can be used to operate electrical components such as opening or closing your hand, rotating your wrist or flexing and extending your elbow.
Traditional myoelectric prostheses target specific muscle groups to activate a particular electrode. For example, the muscles on the front of your forearm may close the prosthetic hand, and the muscles on the back of your forearm may close it. There are now systems by which several electrodes within the prostheses recognize a pattern of muscle activity to represent an action. This leads to faster and more intuitive control of the device.