Abstract: The present invention is directed to a pre-positionable prosthetic hand, including one or more pre-positionable joints. Pre-positionable joints in accordance with embodiments of the present invention include a multi-axial thumb joint, a metacarpal-phalangeal joint and a wrist joint. Additionally, the present invention may include a number of pre-positionable phalanges or fingers having a segmented construction, which allows them to be placed in various positions. The present invention may be used in connection with a pentadactyl glove and may be positioned in such griping positions as: a key or lateral grip, a hook grip, a cylindrical grip, a spherical grip and a tip-pinch grip.

Abstract: A prehensor is provided comprising embodiments of a variable mechanical advantage mechanism, the prehensor including a first mechanical advantage for sizing an object, and a second mechanical advantage for gripping the object. Embodiments of the variable mechanical advantage mechanism include a brake assembly and multiple embodiments of a brakeless assembly. Additionally, multiple embodiments of a selectable voluntary opening/voluntary closing mechanism are provided, whereby a single prehensor can be switched back and forth between a voluntary closing mode and a voluntary opening mode. Additional embodiments include a safety clutch, an improved prehensor tendon, replaceable digits, and self decontaminating digits.