Abstract: A vacuum-assisted suspension device for a lower limb prosthesis secures the prosthesis to a residual body portion. Sandwiched between the residual body portion and an impermeable socket is a flexible liner made of an impermeable material that is porous to allow the transport of air and fluid directly away from the residual body portion to the outer surface of the liner. A fabric distribution layer is located over the liner and between the liner and the socket to allow transmission of such extracted air and fluid laterally over the liner to an evacuation port in the socket. The evacuation port has an associated one-way valve. During use, loading of the socket compresses the flexible liner and air is expelled via the evacuation port. When the load is removed, a vacuum is created directly between the residual body portion and the socket, the vacuum being maintained by the one-way valve.

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 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 knee joint mechanism has an hydraulic load-activated knee-stabilizing device for resisting joint flexion. A rotary piston (34) connected to one part of the mechanism is rotatable within a fluid-filled fluid displacement chamber (18) associated with another part of the mechanism to drive fluid through a fluid passage which contains a main valve (38) which restricts or allows joint flexion according to the position of a valve member within the valve. The valve member is movable towards an open position in response to fluid pressure in the fluid passage upstream of the valve member caused by application of a flexion torque to the knee joint mechanism, movement of the valve member in the direction of the open position being at least resisted by a valve control arrangement actuated by application of the wearer's weight. The weight-responsive valve control arrangement is preferably a weight-responsive pilot valve (32) for hydraulically resisting movement of the valve member of the main valve.

Abstract: A prosthetic knee joint mechanism has an hydraulic load-activated knee-stabilising device for resisting joint flexion. A rotary piston connected to one part of the mechanism is rotatable within a fluid-filled fluid displacement chamber associated with another part of the mechanism to drive fluid through a fluid passage which contains a main valve which restricts or allows joint flexion according to the position of a valve member within the valve. The valve member is movable towards an open position in response to fluid pressure in the fluid passage upstream of the valve member caused by application of a flexion torque to the knee joint mechanism, movement of the valve member in the direction of the open position being at least resisted by a valve control arrangement actuated by application of the wearer's weight. The weight-responsive valve control arrangement is preferably a weight-responsive pilot valve for hydraulically resisting movement of the valve member of the main valve.

Abstract: A lower limb prosthesis for an above-knee amputee that includes a dynamically adjustable knee movement control unit arranged to control flexion and/or extension of a knee joint of the prosthesis automatically in response to a sensed step-to-step variability of at least one kinetic or kinematic parameter of locomotion in order to reduce the step-to-step variability.

Abstract: A strut component for an orthosis, especially a knee orthosis, takes the form of a deformed ductile metallic tube containing uncured plastics and fibre composite material. The tube has a cross-section which is much longer than its width and with parallel sides, and the composite core is a close-fit within the tube, the internal cross-sectional area of the tube being no more than Kc2 where c is the internal circumference of the tube and k is a number less than or equal to 0.1. When the orthosis is constructed, the strut is shaped to suit the limb to be supported and heated to cure the composite core.

Abstract: A lower limb prosthesis for an above-knee amputee has an adaptive control system which includes a knee flexion control device arranged to resist flexion at the knee joint both hydraulically and pneumatically by means of a dual piston and cylinder assembly. Sensors arranged to sense knee bending moments and knee flexion angle provide electrical signals which are fed to a processing circuit for automatically adjusting the hydraulic and pneumatic resistance to flexion according to the activity mode of the amputee and, when walking, according to the speed of the cylinder containing hydraulic fluid. The hydraulic resistance to flexion predominates during the stance phase and pneumatic resistance predominates during the swing phase. Provision is made for programmable resistance during level walking, walking on an incline, descending stairs and during a stumble.

Abstract: An artificial knee comprises first and second pivotally interconnected knee components and first and second interengaging brake components for locking the knee components together. The first and second brake components are associated respectively with the first and second knee components, respectively. The second brake component is made of a resiliently deformable material. The arrangement is such that, when the artificial knee is subjected to a first load condition, the brake components are substantially free to slide against one another, and when the artificial knee is under a second, higher load condition, the second brake component is resiliently deformed against the first brake component to lock the two brake components together, thereby locking the two knee components together.

Abstract: An artificial limb has an endoskeletal shin component which is of generally constant H-shaped cross section and is formed by injection molding from thermoplastics material. In a preferred embodiment, the limb has a foot keel which is integrally molded with the shin component. The keel also has upper flanges which are contiguous with anterior and posterior flanges of the shin component. Such a limb can be made light in weight yet strong in terms of resistance to transverse bending moments, and can be inexpensively produced. The constant cross section of the shin component allows it to be cut to a required length and clamped to an upper limb component.

Abstract: A unitary foot and shin component for a lower limb prosthesis has a one piece thermoplastic endoskeletal foot keel and shin member and a continuous flexible cosmesis. The cosmesis includes a resilient foot body which is molded directly onto the keel so as to embed the keel, and an integral flexible and hollow shell which surrounds the shin member but is spaced from it. By forming the foot body and the hollow shell as a single polyurethane molding, the foot and shin can be supplied as a single component, ready for connection to a stump socket and alignment coupling.

Abstract: A single-piece fibre-reinforced plastics shin component for a lower limb prosthesis for a below-knee amputee has an elongate resilient energy-storing blade and, integrally formed at a proximal end of the blade, an alignment plate extending generally anteriorly and perpendicularly with respect to the blade to form at least part of an alignment device for adjusting the position of the blade relative to an upper limb component. The blade is straight and of constant cross-section at least over its distal end portion to allow it to be cut to length to suit the amputee.

Abstract: A method of constructing an artificial limb from individual components comprising providing a plurality of logical unit tables (2A, 2B) arranged to contain data related to a respective class of the components, providing a plurality of component records (4A, 4B) located in at least one of the logical unit tables (2A, 2B) arranged to hold data related to a respective plurality of components of the same class providing an interface field (6A, 6B) located in each respective component record (4A, 4B) arranged to hold data related to an interface of the component to which the component record relates, selecting a component record (4A, 4B) generating a list of compatible component records from a logical unit table (2A, 2B) other than the logical unit table containing the selected component record (4A, 4B), which are compatible with the selected component taking account of the information contained in the interface fields (6A, 6B) of the selected component record (4A, 4B) and the component records in the other logica

Abstract: A single-piece fibre-reinforced plastics shin component for a lower limb prosthesis for an above-knee amputee has an energy storing blade and, integrally formed therewith, a shin cradle in the form of a channel section which has a pair of pivot supports formed as flanges extending away from one of the major surfaces of the blade. Each flange has a pair of holes defining transverse pivot axes, one of which is a knee axis and the other of which is a pivot axis for mounting the distal end of a knee movement control unit. These holes together define a longitudinal axis which is generally parallel to and to the anterior of the blade. The blade merges smoothly into the channel section and, over a distal end portion, is straight and of constant cross-section to allow the blade to be cut to length to suit the amputee.

Abstract: An adaptive control system for an artificial limb has a piston and cylinder assembly for controlling knee joint flexion, an electronically driven motorised valve for varying the damping effect of the assembly, a proximity sensor for sensing knee flexion, and a processor circuit for mounting on the limb. The system also has a radio receiver connected to the processor circuit and an operator control unit for remote transmission of command signals to the receiver. In a teach mode, the system allows an operator to increment the valve opening by remote control to optimise operation of the limb, and to cause the processor circuit to record selected valve openings in conjunction with average step period values which are produced automatically by the system during use of the limb. Recording a new selected valve opening causes the processor circuit on the limb automatically to calculate a set of control data relating valve openings to walking speed ranges.

Abstract: An artificial leg includes a knee mechanism having means for restricting knee flexing movement during the stance phase of the walking cycle. The restricting means includes a piston and cylinder assembly so coupled in the mechanism that the piston is movable in the cylinder with knee flexion and extension. The knee mechanism includes two chassis parts arranged to move relatively to each other when an axial load is applied to the limb. One end of the piston and cylinder assembly is connected to one of the chassis parts while the other chassis part engages a control member coupled to a valve inside the piston and cylinder assembly so that the valve is operated in response to relative load-dependent movements of the chassis parts in order to restrict the flow of fluid and thereby create resistance to knee flexion during the stance phase. The chassis parts are connected together by an anterior pivot joint and are resiliently moveable relative to each other according to applied load.

Abstract: In a lower limb prosthesis an energy storing foot is combined with a resilient ankle joint which is arranged to allow planatar flexion but substantially to prevent dorsiflexion. The ankle joint comprises a ball and socket joint, the socket of which is extended downwardly on the anterior, medial and lateral sides to for a skirt positioned so as to compress a resilient ring encircling a ball member of the ball and socket joint. Metal plates are embedded in the anterior part of the ring to prevent significant dorsiflexion. The foot has a keel having a lower spring portion connected at its posterior end as a cantilever to an upper ankle mounting portion. These two portions may be formed as a single carbon fibre reinforced plastics moulding or individually as part of a two-piece keel with the ankle mounting portion rigid and the spring portion as simple fibre-reinforced strip.

Abstract: An artificial ankle joint (FIG. 1) is of the kind which connects a shin member to a foot, by means of a ball and socket joint. The socket has adjacent main and subsidiary socket portions. The main socket portion has a first part, which engages the elastic covering of the ball, and a second part which extends down from the first part and receives within it the subsidiary socket portion. A circlip locks the parts together. The main socket portion includes an integral skirt which engages an annular elastic buffer which is mounted around the ball shank.

Abstract: An artificial leg has a ball and socket ankle joint, the socket of which has upper and lower portions. They are connected together and clamped over the ball by a turnbuckle ring. This provides an adjustable shin and foot connection which permits use of a rubber-encased ball of sufficient size, without taking up too much shape within the ankle region. Also disclosed is a movable patella member and a vertically jointed two part foam covering.