Abstract: A prosthetic includes a pair of prosthetic members movably coupled together to allow movement of the pair of prosthetic members with respect to one another. A hydraulic actuator or damper including hydraulic fluid in a hydraulic chamber is coupled to one of the pair of prosthetic members. A hydraulic piston is movably disposed in the hydraulic chamber and coupled to another of the pair of prosthetic members. A hydraulic flow channel is fluidly coupled between opposite sides of the chamber to allow hydraulic fluid to move between the opposite sides of the chamber as the hydraulic piston moves therein. A voice coil valve is coupled to the hydraulic flow channel to vary resistance to flow of hydraulic fluid through the flow channel, and thus movement of the piston in the chamber, and thus influencing a rate of movement of the pair of prosthetic members with respect to one another.

Abstract: A range of motion (ROM) prosthetic foot and passive dampening ankle joint have limited dorsiflexion-plantarflexion (up and down) pivoting to accommodate different environments, and a spring to provide resilient resistance to plantarflexion (or lowering of the toe), and to bias the foot in dorsiflexion (or raising the toe). The ankle joint has a rear pivot rearward of a hydraulic link for a smooth feel. The ankle joint has an internal bumper in a hydraulic cylinder for a smooth feel. The ankle joint has an internal hydraulic compensator disposed in the cylinder and carried by the piston to equalize volume.