Abstract: A prosthetic ankle device is disclosed herein. The prosthetic ankle device includes a hydraulic cylinder with a first chamber, a second chamber, and a piston separating the first chamber and the second chamber. The chambers are filled with hydraulic fluid. During plantarflexion, the hydraulic fluid flows between the first chamber and the second chamber via a first passage and a first check valve. During dorsiflexion, the hydraulic fluid flows between the first chamber and the second chamber via a second passage and a second check valve.

Abstract: A prosthetic ankle device is disclosed herein. The prosthetic ankle device includes a hydraulic cylinder with a first chamber, a second chamber, and a piston separating the first chamber and the second chamber. The chambers are filled with hydraulic fluid. During plantarflexion, the hydraulic fluid flows between the first chamber and the second chamber via a first passage and a first check valve. During dorsiflexion, the hydraulic fluid flows between the first chamber and the second chamber via a second passage and a second check valve. The ankle device includes a third passage and a third check valve, where the third passage diverts flow of the hydraulic fluid from the second passage based at least in part on a system status.

Abstract: A hydraulic prosthetic device has upper and lower portions and a hydraulic cylinder coupled thereto for damping relative motion. The cylinder has a movable piston and a first and second chamber. A three-way valve includes a housing and a movable portion cooperating to define a hydraulic circuit. The movable portion has a master port, an inlet port and an outlet port, and the housing has an inlet opening, an outlet opening, and a master opening each positioned to fluidly communicate with the respective port. The inlet port and/or the inlet opening, and the outlet port and/or the outlet opening are shaped such that movement of the movable portion of the valve relative to the housing varies a resistance to the fluid flow related to movement or the prosthetic portions in both directions.