About 3,000 years ago, ancient Egyptians developed the first functional prosthesis: an artificial big toe. In 2011, researchers showed that Egyptians with the fake toes would have had a much easier time walking around in sandals than people who were missing their big toes but didn’t get prostheses.
Prostheses are artificial devices that take the place of missing or injured body parts. Some prosthetic body parts are merely cosmetic — artificial eyes, for example — but prostheses that replace bones, such as prosthetic limbs or joints, have a functional purpose.