A prosthetic device having a housing, an axle, at least three housing vanes, a flow medium and a valve. The axle is disposed within the housing and moveable independently of the housing. The axle has an axle reservoir and at least three axle vanes extending from the axle to contact the chamber wall. The three housing vanes extend from a chamber wall and contact the axle. A first opening and a second opening are formed in each axle vane. The flow medium is contained entirely within the chamber and the axle reservoir. The valve is disposed in the axle and operable in response to movement of the axle in a first direction relative to the housing to allow the flow medium to enter the axle reservoir from the chamber for storage under pressure.
