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 prothesis an energy storing foot (10) is combined with a resilient ankle joint (13) which is arranged to allow plantar flexion but substantially to prevent dorsi-flexion. The ankle joint (13) comprises a ball and socket joint (42), the socket (44) of which is extended downwardly on the anterior, medial and lateral sides to form a skirt (44A) positioned so as to compress a resilient ring (54) encircling a ball member (46) of the ball and socket joint (42). Metal plates (56) are embedded in the anterior part of the ring to prevent significant dorsi-flexion. The foot (10) has a single-piece carbon fiber reinforced plastics keel (12) having a lower spring portion (12B) connected at its posterior end as a cantilever to an upper ankle mounting portion (12). The resilient of the foot (10) is adjustable by means of a transversely extending support bar (28) which can be moved longitudinally by rotating an adjusting screw (30).

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.

Abstract: An improved artificial leg has a ball and socket ankle joint (3) connecting a foot (2) to a shin member (1). The ankle joint comprises a two-part socket (5A, 5B) enclosing a part-spherical ball member (4) with an elastic sleeve (6) sandwiched between the socket and the ball member (4) to allow resilient flexion of the foot (2) relative to the shin member (1). In order to provide relatively more resistance to dorsi-flexion than to plantar-flexion, an elastic buffer in the form of a ring (11) is disposed around a coupling shank portion (4A) of the ball member (4) to engage a downwardly extending anterior skirt portion (12) of the socket. In the preferred embodiment of the invention the skirt portion (12) also extends around each side of the ring (11) to provide resistance to medial and lateral flexion.