A prosthesis 1 for providing at least one mechanically operable digit member. The prosthesis 1 has at least one digit member 3 extending generally tangentially with respect to a fixed worm gear wheel means 5 on a support member of the prosthesis and mounted for rotation about the worm gear wheel means axis 8. The digit member has a drive motor 7 operable to drive a worm means 13. The worm means 13 is in engagement with the worm gear wheel means 5 so that when the drive motor is operated, in use of the prosthesis, the digit member 3 moves around the worm gear wheel means 5, in which the worm means 13 is disposed outwith the digit member 3.
