Abstract: A prosthetic ankle and foot combination has an ankle joint mechanism constructed to allow damped rotational movement of a foot component relative to a shin component. The mechanism provides a continuous hydraulically damped range of ankle motion during walking with dynamically variable damping resistances, and with independent variation of damping resistances in the plantarflexion and dorsiflexion directions. An electronic control system coupled to the ankle joint mechanism includes at least one sensor for generating signals indicative of a kinetic or kinematic parameter of locomotion and/or walking environment, the mechanism and the control system being arranged such that the damping resistances effective over the range of motion of the ankle are adapted automatically in response to such signals. Single and dual piston hydraulic damping arrangements are disclosed, including arrangements allowing independent heel-height adjustment.

Abstract: A prosthetic ankle and foot combination has an ankle joint mechanism constructed to allow damped rotational movement of a foot component relative to a shin component. The mechanism provides a continuous hydraulically damped range of ankle motion during walking with dynamically variable damping resistances, and with independent variation of damping resistances in the plantarflexion and dorsiflexion directions. An electronic control system coupled to the ankle joint mechanism includes at least one sensor for generating signals indicative of a kinetic or kinematic parameter of locomotion, the mechanism and the control system being arranged such that the damping resistances effective over the range of motion of the ankle are adapted automatically in response to such signals. Single and dual piston hydraulic damping arrangements are disclosed, including arrangements allowing independent heel-height adjustment.

Abstract: An hydraulic heel-height adjustment device for a lower limb prosthesis has a foot-mounting component (18) for detachably mounting a prosthetic foot and a shin component pivotally connected to the foot-mounting component allowing angular adjustment of the foot-mounting component relative to the shin component about a heel-height adjustment axis. The relative angular position is set by an hydraulic piston (42) and cylinder assembly which has a chamber (40) in the shin component containing a piston (42) arranged to execute a translational movement in the chamber when adjustment is required. A bypass passage interconnects parts of the chamber on opposite sides of the piston, this passage containing a manually operable valve which is spring-biased towards a closed position. The piston has a piston rod pivotally connected to the foot-mounting component by a pivot joint defining a medial-lateral axis parallel to and spaced from the heel-height adjustment axis.

Abstract: A self-aligning prosthetic foot and ankle assembly has an ankle unit pivotally mounting a foot component. The ankle unit contains a hydraulic piston and cylinder assembly having a piston which is linearly movable within a cylinder. The axis of the cylinder is coincident with a shin axis defined by a shin connection interface on the ankle unit. Bypass passages containing damping resistance control valves provide continuous hydraulic damping of dorsi and plantar ankle flexion, the unit being such that, over the major part of the range of damped movement, there is no resilient biasing in either the dorsi or the plantar direction. This confers a number of advantages, including stabilisation of standing, balance control, and improved stair-walking and ramp-walking.