With the invention of the computer and advancements in technology we progressed from manually operated hooks to electronic devices that were triggered my muscle input and controlled by computers and batteries. Mioelectric Prosthetic hands are hugely popular now and multiple companies around the globe are making a variety of styles. All mioelectric hands are controlled by the users muscle input or some other sort of input switching device ie, nudge switch, transducer, etc. In the past this switch would simply open or close the hand, at one speed, with one strength. It was a very limited situation but now we have proportional controls that allow the users to open at a variety of speeds and different grip strengths.