GB2163961A

GB2163961A - Improved artificial foot

Info

Publication number: GB2163961A
Application number: GB08521490A
Authority: GB
Inventors: Victor James Woolnough
Original assignee: Blatchford & Sons Ltd
Current assignee: Blatchford & Sons Ltd
Priority date: 1984-09-03
Filing date: 1985-08-29
Publication date: 1986-03-12
Also published as: GB2163961B; GB8521490D0

Abstract

An artificial foot has a keel (10) which is rotatable about axis (16) relative to a connection member (14). The latter is fixed to an ankle joint (18A). The rear portion of the keel (10) has two spaced parallel side walls (10A) between which are two spaced parallel integral ears (14A) of the connection member (14). The walls and ears are slotted (20, 24) and the slots are inclined. Extending through the four slots is a transverse bar (28) with four slider blocks (32) each running in a respective one of the four slots (20, 24). The bar (28) and blocks (32) are adjustably movable backwards and forwards by a rotatable screw or bolt (30), accessible at the rear of the foot. When the screw (30) is turned and the bar and blocks moved, the keel (10) is turned relative to the member (14) about the axis (16), to adjust the foot angle and thus the heel height. <IMAGE>

Description

SPECIFICATION Improved artificial foot This invention relates to an artificial foot having means for adjusting heel height.

Lower limb prosthesis is normally supplied to a patient with the foot set at an angle to the shin depending on the patient's normal footwear. With a male patient, the angle may typically be set to give a heel height of 25 mm relative to the ball of the foot, but women patients often require greater heel heights to suit the higher heels of womens' shoes.

One known heel height adjustment means includes the provision of two mating, serrated cylindrical surfaces on the ankle assembly and foot keel respectively, so that the foot may be bolted to the ankle in a number of alternative positions of different heel heights. However, since alteration of the heel height setting requires the release of a structural connection, i.e. the bolt, between the foot and the ankle assembly, it is preferred with such a construction that heel height adjustments should not be carried out by the patient but rather by a prosthetist. This restricts the footwear that can be worn, and there is consequently a need, particularly amongst female patients, for a simple and secure means of adjusting heel height when changing shoes.

This invention provides an artificial foot comprising a connection member by which the foot is in use connected to a shin or other leg member, and a foot body or keel, the connection member and the keel being adjustably rotatable relatively to one another for adjustment of the angle of the foot in relation to the axis of the shin or other leg member whereby heel height can be adjusted.Also according to this invention an artificial foot may comprise a connection member by which the foot is connected in use to a shin or other leg member, a foot keel the connection member and the keel being adjustably rotatable relatively to one another, and an adjustment device associated with the connection member and the keel in such manner that adjusting movement of the adjusting device causes the connection member and the keel to rotate relative to one another so as to adjust the angle of the foot in relation to the axis of the shin or other leg member whereby heel height can be adjusted.

In the artificial foot of this invention, heel height may be adjusted by the patient without disturbing or releasing the structural connection between the foot and an ankle joint or shin or other leg member.

-Two embodiments of foot assembly in accordance with the invention will now be described by way of example with reference to the drawings, in which: Figure 1 is a diagrammatic partly section view of one embodiment; Figure 2 is a plan view of part of the embodi anent of Figure 1; and Figure 3 is a partly sectioned view of another embodiment.

The embodiment of a foot assembly seen in Figures 1 and 2 has a structural keel 10 with a recess 12 housing a pivotable connection member 14.

This connection member 14 connects the foot to a ball and socket ankle joint, shown in outline at 18A, which is in turn connected to a shin tube 18B.

The medial/lateral pivot axis 16 intersects the shin axis 18. The rear portion of the keel 10 has side walls 10A and 10B (Figure 2) with two generally radially directed and mutually parallel slots 20 and 22 which are alongside similar slots 24 and 26 cut in integral, parallel, rearwardly extending ears 14A and 14B of the connection member 14. These latter slots 24 and 26 are, in general, at an angle to the slots 20 and 22, as seen in Figure 1.

A bar 28 extends laterally through all four slots 20, 22, 24 and 26 (Figure 2), and carries square section slider blocks 32, 34, 36 and 38 having dimensions corresponding to the width of the slots, thus spreading the load from the bar 28 to the slots. Blocks 32, 34, 36 and 38 are pivotable on the bar 28. The bar 28 (Figure 2) has a threaded aperture 30A through which the screw 30 passes. The screw 30 is mounted in a rear wall 10C of the keel 10 and has a hexagon socket head accessible through a hole in the cosmetic covering at the rear of the foot where it can be reached readily by the patient.

It will be seen that rotation of the screw 30 moves the bar 28 and slider blocks backwards or forwards in relation to the axis 16, causing the keel 10 to pivot about axis 16 relatively to the connection member 14, so as to alter the foot heel height.

A strap 40 linking the connection member 14 and a flexible toe portion 42 of the foot, which portion 42 is movable relative to the keel 10, causes the toe angle to be adjusted as the heel height is adjusted.

The foot assembly is connected in a known manner to the ball and socket ankle joint 18A by a bolt 44 housed in the connection member 14. In Figure 1, the interface between the connection member 14 is a simple planar surface. However, the connection member 14 may have a plain or serrated concave cylindrical surface mating with a plain or serrated convex cylindrical surface on the ankle joint to allow the initial setting of a mean heel height by a prosthetist when the foot is attached to the ankle joint, so that operation of the screw 30 by the patient results in adjustment to either side of this mean height.

Figure 3 shows another embodiment, giving a higher mean heel height and a larger range of heel height adjustment. The rear wall 10C of the keel 10 has an angled portion defining an upwardly inclined axis for the adjustment screw, as shown.

Thus in Figure lit will be seen that the slots 24, 26 of the connection member 14 are inclined with respect to the generally horizontal slots 20, 22 of the keel walls, whereas the reverse obtains in Figure 3.

In both embodiments described above, the bending movement above the axis 16 is transmitted by the blocks 32, 34, 36 and 38 generally perpendicularly to the screw 30. In these circumstances the friction between the screw and the other components is such that no separate locking means for the adjusting element is required.

Claims

1. An artificial foot comprising a connection member by which the foot is in use connected to a shin or other leg member, and a foot body or keel, the connection member and the keel being adjustably rotatable relatively to one another for adjustment of the angle of the foot in relation to the axis of the shin or other leg member whereby heel height can be adjusted.

2. An artificial foot comprising a connection member by which the foot is connected in use to a shin or other leg member, a foot keel, the connection member and the keel being adjustably rotatable relatively to one another, and an adjustment device associated with the connection member and the keel in such manner that adjusting movement of the adjusting device causes the connection member and the keel to rotate relative to one another so as to adjust the angle of the foot in relation to the axis of the shin or other leg member whereby heel height can be adjusted.

3. An artificial foot according to claim 2 wherein the adjusting device is manually adjustable at the rear of the foot.

4. An artificial foot according to any preceding claim wherein the keel has spaced side walls between which the connection member is rotatably mounted for relative rotation of the connection member and keel about a medial/lateral axis.

5. An artificial foot according to claim 4 wherein the medial/lateral axis intersects the axis of the shin or other leg member.

6. An artificial foot according to claim 4 when dependent on claim 2 or claim 3, wherein the connection member has two integral, parallel, spaced, rearwardly extending ears between the side walls of the keel, and each ear has a slot and each side wall has a slot, the ear slots being parallel and the side wall slots being parallel and the ear slots being at an angle to the side wall slots, and wherein the adjustment device comprises a bar extending laterally through all the slots, and a threaded screw rotatably mounted by the bar and the rear of the keel in such manner that rotational adjustment of the screw causes the bar to move forward or backward along the slots and thereby cause the connection member and keel to rotate relatively to a required position of adjustment.

7. An artificial foot according to claim 6 wherein the bar has a threaded aperture through which the screw passes such that rotational adjustment of the screw causes the forward or backward movement of the bar in the slots.

8. An artificial foot according to claim 6 or claim 7, wherein slider blocks of square section are rotatably mounted on the bar, each block sliding in a a respective slot.

9. An artificial foot according to any preceding claim having a flexible toe portion which is mova ble relative to the keel and which is connected to the connection member for adjustment of the toe angle as heel height is adjusted.

10. An artificial foot constructed and arranged substantially as herein described and shown in the drawings.