Prosthetic Ankle Joint Mechanism

摘要

A prosthetic foot and ankle assembly includes a foot component and an ankle joint mounted thereto and having a fixed range of dorsi-plantar flexion. The ankle joint includes a joint mechanism in the form of a hydraulic linear piston and cylinder assembly having a pair of chambers on opposite sides of the piston to provide hydraulic damping continuously over the range of dorsi-plantar flexion. The joint mechanism further includes a valve arrangement controlling the flow of hydraulic fluid between the chambers. The valve arrangement includes first and second adjustable valves for independently controlling dorsi-flexion damping resistance and plantar-flexion damping resistance respectively. The joint mechanism includes a first flexion limiter that limits dorsi-flexion of the joint mechanism to a dorsi-flexion limit and a second flexion limiter that limits plantar-flexion of the joint mechanism to a plantar-flexion limit, thereby defining the fixed range of dorsi-plantar flexion.