Abstract: A lower limb prosthesis comprises a foot component and an ankle unit pivotally mounted to the foot component. The ankle unit comprises an ankle joint mechanism comprising a hydraulic piston and cylinder assembly for providing hydraulic damping whenever the ankle joint flexes, and a vacuum mechanism comprising a pneumatic piston and cylinder assembly for generating a vacuum. The hydraulic and pneumatic piston and cylinder assemblies are arranged such that the vacuum mechanism generates a vacuum during plantar-flexion of the ankle unit.

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.

Abstract: 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.

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 plantar-flexion and dorsi-flexion 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: 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 plantar-flexion and dorsi-flexion directions. The mechanism also provides for adjustment of a second piston element with respect to a shin component when a first valve is closed and a locking valve is open to adjust a reference angular position independently of the damping function that occurs during walking.

Abstract: A prosthetic ankle has an ankle joint body (10A) constituting a shin component and a foot component (12). The ankle joint body (10A) is pivotally connected to the foot component (12) by a first pivotal connection (14) defining a medial-lateral ankle joint flexion axis. The ankle joint body (10A) also forms the cylinder of an ankle joint piston and cylinder assembly with a superior-inferior central axis, the cylinder housing a piston (16) with upper and lower piston rods (16A, 16B). The lower piston rod (16B) is pivotally connected to the foot component (12) at a second pivotal connection (18). As the ankle joint body (10A) pivots about the ankle joint flexion axis, the piston (16) moves substantially linearly in the cylinder formed by the ankle joint body. The cylinder is divided into upper and lower chambers (20A, 20B).

Abstract: A lower limb prosthesis comprises an attachment section (10), a shin section (12), a foot section (14), a knee joint (16) pivotally connecting the attachment section (10) and the shin section (12), and an ankle joint (22) pivotally connecting the shin section (12) and the foot section (14). The knee joint includes a dynamically adjustable knee flexion control device (18) for damping knee flexion. The prosthesis further comprises a plurality of sensors (52, 53, 54, 85, 87) each arranged to generate sensor signals indicative of at least one respective kinetic or kinematic parameter of locomotion or of walking environment, and an electronic control system (100) coupled to the sensors (52, 53, 54, 85, 87) and to the knee flexion control device (18) in order dynamically and automatically to modify the flexion control setting of the knee joint (16) in response to signals from the sensors.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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: In a lower limb prosthesis an ankle unit has a combination of an hydraulic piston and cylinder assembly providing a continuously damped range of ankle flexion and a resilient telescopic shock absorber. The damping resistance of the piston and cylinder assembly is the predominant resistance to ankle flexion and is provided by a piston which is axially moveable in a cylinder centered on the shin axis. The wall of the cylinder has a cylindrical outer bearing surface for a sleeve which is translationally displaceable relative to the piston and cylinder assembly according to the axial load, the sleeve being resiliently mounted by a compression spring which extends axially within the sleeve and has an integral end portion forming an upper bulkhead of the cylinder. The sleeve is also rotatable on the cylinder wall, the spring providing torsional resistance.

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.

Abstract: A self-teaching lower limb prosthesis, for an above-knee amputee, including a dynamically adjustable joint movement control unit arranged to control operation of the joint automatically. A control unit electrically stores a target relationship between a kinetic or kinematic parameter of locomotion and walking speed. The relationship defines a number of values of the parameter associated with different walking speeds. The control unit generates monitoring signals representative of walking speed values and values of the parameter occurring at different walking speeds. An adjustment system adjusts the control unit automatically when the monitoring signals indicate deviation from the target relationship so as to bring the parameters close to that defined by the target relationship.

Abstract: A lower limb prosthesis for a transfemoral amputee, having a shin portion, ankle portion and a forefoot part of the foot portion formed as an integral fibre-reinforced plastics leaf spring component. This integral component is adjustably mounted to a knee joint which has a knee chassis, a cradle pivotally connected to and depending from the knee chassis, and a flexion control unit in the form of a piston and cylinder assembly interconnecting the knee chassis and the cradle. The shin portion has an elongate resilient section of constant cross-section oriented substantially vertically. The connection of this resilient section to the knee joint cradle and the arrangement of the cradle is such that the vertical distance between the knee axis of rotation and the location of the connection is less than 25% of the vertical distance between the knee axis and the lowest weight-bearing surface of the foot portion.

Abstract: In a lower limb prosthesis an ankle unit has a combination of an hydraulic piston and cylinder assembly providing a continuously damped range of ankle flexion and a resilient telescopic shock absorber. The damping resistance of the piston and cylinder assembly is the predominant resistance to ankle flexion and is provided by a piston which is axially moveable in a cylinder centred on the shin axis. The wall of the cylinder has a cylindrical outer bearing surface for a sleeve which is translationally displaceable relative to the piston and cylinder assembly according to the axial load, the sleeve being resiliently mounted by a compression spring which extends axially within the sleeve and has an integral end portion forming an upper bulkhead of the cylinder. The sleeve is also rotatable on the cylinder wall, the spring providing torsional resistance.

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 plantar-flexion and dorsi-flexion 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: 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: In a stabilising knee joint for a lower limb prosthesis, weight-activated knee stabilisation is achieved by interen-gagement of a brake disc (32) associated with an upper knee chassis (10) and a brake member (34) associated with a shin carrier (18). The knee chassis is mounted on a posterior end portion (14P) of a resiliency biased activation arm (14) which pivots on the carrier (18). To provide a mechanical advantage in the brake action, a circumferential portion of the brake disc (32) is tapered, and the brake member (34) has a correspondingly tapered channel which receives the circumferential disc portion. The arrangement of the brake members (32, 34) and their mounting on the shin carrier (18) is such that substantial release of frictional engagement of the brake members can be substantially achieved even when a knee flexion moment is applied to the joint.

Abstract: A self-teaching lower limb prosthesis, for an above-knee amputee, including a dynamically adjustable joint movement control unit arranged to control operation of the joint automatically. A control unit electrically stores a target relationship between a kinetic or kinematic parameter of locomotion and walking speed. The relationship defines a number of values of the parameter associated with different walking speeds. The control unit generates monitoring signals representative of walking speed values and values of the parameter occurring at different walking speeds. An adjustment system adjusts the control unit automatically when the monitoring signals indicate deviation from the target relationship so as to bring the parameters close to that defined by the target relationship.