GB2330311A

GB2330311A - Ankle-foot orthosis

Info

Publication number: GB2330311A
Application number: GB9814726A
Authority: GB
Inventors: Robert John Watts
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-10-15
Filing date: 1998-07-07
Publication date: 1999-04-21
Also published as: GB9721863D0; GB9814726D0; GB2330309B; GB2330309A

Abstract

An ankle-foot orthosis 1 for resisting plantarflexion of a patient's foot 5, the orthosis comprising: a resilient rib 3 locatable, in use, along and in abutment with at least a portion of the dorsal aspect of the patient's foot 5 and at least a portion of the patient's lower leg, the orthosis comprising means 7 for securing the rib 3 to the patient's foot and lower leg.

Description

1 ANKLE-FOOT ORTHOSIS This invention relates to anklefoot orthoses.

2330311 Orthoses are mechanical devices which impose forces upon a limb of a patient and can be used for a variety of different purposes. For example, orthoses may be provided for supportive, functional, corrective or protective purposes, or for a combination of these. Ankle-foot orthoses are typically provided to provide protection to the ankle and foot of a patient as well as to provide support against excessive plantarflexion or dropping of the foot. In addition to this resistive function, they may also be employed to assist dorsiflexion of the patient's foot during the push off phase of the patient's gait. Orthoses may also be employed to resist plantarflexion caused, for example, by, the weight of bedcoverings or the like on a patient ' s feet during extended periods of bedrest.

Foot plantarflexion is a medical condition that can arise from a variety of causes, for example disease or congenital abnormality. Patients affected by this condition typically experience difficulty in walking as they must lift their foot excessively frorn the ground in order to avoid stumbling.

A variety, of different ankle-foot orthoses have previously been proposed for resisting plantarflexion, and in sonic cases for additionally, assisting dorsiflexion. Figures]a, lb, 2a and 2b illustrate two of these previously proposed devices.

Figure la illustrates one previously proposed ankle-foot orthosis before it is assembled on a patient. The orthosis 10 must be used in conjunction with a shoe 12 that provides close contact between the shoe and the foot in the region of the instep. The orthosis 10 comprises a pair of supporting metal uprights 14, one connected to either side of the shoe 12 in the region of the heel 16. The connections each comprise a plantarflexion stop 18 that resists foot drop and may also include springs (not shown) to assist dorsiflexion. The upper ends of the uprights are connected to a 2 supporting strap 20 which is securable about the patient's calf. With reference to Figure lb, it can be seen that the supporting strap 20 provides support about the patient's calf, and that the plantarflexion stops 18 and shoe 12 provide support under the foot of the patient to resist plantarflexion.

Figures 2a and 2b illustrate another previously, proposed orthosis device which must also be used in conjunction with a shoe that provides close contact between the shoe and the foot in the region of the Instep. In this example, the orthosis 22 comprises a one-piece plastics moulding 24 which comprises a calf abutting region 26 and a sole abutting region 28. The top of the calf abutting region 26 is provided with a closure mechanism 27 that enables the device to be secured to the calf of a patient. The sole abutting region 28 acts in conjunction with the shoe 30 to support the foot of the patient. The stiffness of the plastics moulding and the shape thereof in the region of the ankle defines the amount of resistance to plantarflexion. If more resistance is required, then the gap across the front of the ankle can be reduced, or the stiffness of the plastics can be increased.

Both of the afore m enti oned previously proposed devices adequately support the foot of a patient to resist plantarflexion. However, they both exhibit serious deficiencies that make them highly, unpopular with patients.

A first disadvantage is that both of the previously proposed orthoses are large bulky devices which are clearly visible when worn. Thus, the patient's illness or abnormality is immediately, apparent to others and this can adversely affect the patient's state of mind. This problem can be particularly apparent with child patients as the orthosis I's an immediately obvious difference which other children can ridicule. It can also be a serious problem for adult patients as a visible device immediately labels them as a disabled or abnormal person with corresponding ramifications for their personal and working lives.

A further disadvantage is that both of these previously proposed devices must 3 be worn with shoes. Thus, if a patient wished to walk without shoes or to go swimming, for example, then they would have to do so without any means for resisting plantarflexion.

A further disadvantage is that these previously, proposed devices can cause extreme discomfort when worn. This problem is particularly apparent with the orthosis of Figures 2a and 2b as the device extends under the foot of the patient and thus the full weight of the patient bears upon the device when the patient walks.

Yet another disadvantage is that both of these previously, proposed devices are difficult and tirne consuming to put on and take off. Furthermore, the second device often requires the fabrication of special shoes as it is often not possible to fit the device within normal off-the-shelf shoes. Finally, both devices are expensive to make and fit as they must be closely fitted to the feet and legs of the patient, and as they are made from relatively, expensive materials.

It is an object of aspects of the invention to alleviate some or all of these disadvantages.

In accordance with an aspect of the invention, there is provided an anklefoot orthosis for resisting plantarflexion of a patient's foot, the orthosis comprising: a resilient rib locatable, in use, along and in abutment with at least a portion of the dorsal aspect of the patient's foot and at least a portion of the patient's lower leg, the orthosis comprising means for securing the rib to the patient's foot and lower leg.

In one embodiment, the securing means comprises a first strap means securable about one end of the rib and the patient's lower leg. and a second strap means securable about the other end of the rib and the patient's foot.

In another embodiment, the securing rneans comprises a first strap means securable about one end of the rib and the patient's lower leg and a shoe for securing 4 the other end of the rib to the patient's foot.

In another embodiment, the securing means comprises an adhesive, at least end portions of the rib being adhered to the patient's lower leg and foot.

In any event, it is preferred that the rib is of plastics, such as polypropylene or ortholene.

Preferably, the orthosis Is skin coloured and/or fabricated by injection moulding. The orthosis could be formed by stamping from sheet material. The orthosis could alternatively be brightly coloured so as to appeal to children.

In accordance,vIth a second aspect of the invention, there is provided a kit comprising a plurality, of orthoses as described herein, the orthoses being of varying size and shape for fitting to feet of different sizes and shapes. The kit may also comprise differently; coloured orthoses to allow the matching of the colour of the orthosis to the skin colour of the patient.

Embodiments of the present in-,.,eiition will now be described, by, way of example only, with reference to the accompanying drawings, in which:

Figures I a and I b are schematic representations of one previously proposed orthosis; orthosis; Figures 2a and 2b are schematic representations of another previously proposed Figure 3 is a schematic representation of an orthosis according to a first aspect of the invention; Figure 4 is a side view of the orthosis of Figure 3; and Figure 5 is a schematic representation of an orthosis according to a second aspect of the invention.

Figure 3 is a schematic representation of an orthosis 1 that comprises a resilient rib 3 that is locatable in use along the dorsal aspect of the patient's foot 5. As shown, the orthosis 1 extends from approximately the base of the patient's toes up to the lower portion of the patient's shin.

The rib 3 is formed of a material that is preferably relatively lightweight and resilient - such as a plastic. A preferred material is ortholene or pollypropylene, but numerous other suitable materials (such as a metal, an alloy or carbon fibre or similar material for example) will be apparent to persons skilled in the art. The orthosis could be injection moulded, or for a more precise fit could be individually fitted to a 10 patient's fool.

In order for the orthosis to benefit the patient, it must somehow be secured to the patient's foot. In the embodiment of Figure 3, the orthosis 1 is secured to the foot byway of a pair of straps 7, which in the preferred embodiment include mechanical hook-and-loop fasteners (not shown) such as velero' that enable the straps 7 to be secured around the patients foot and lower leg respectively,. Alternative fastening mechanisms, such as pop fasteners, could be provided in addition or instead of velcro'.

When the straps are secured about the patient's foot and lower leg, the orthosis 1 is secured to the patient's foot and plantarflexion is resisted. The arrangement of Figure 3 is particularly advantageous for use in warmer climates as the majority, of the patient's foot is not covered by the orthosis 1.

Figure 4 is a side viem; of the orthosis 1 of Figure 3 illustrating the points at which pressure is applied to the patients foot by the device. As shown, the orthosis 1 applies pressure to the patient's foot at three discrete locations (1), (ii) and (iii).

Application of pressure to the foot at these three locations causes plantarflexion to be resisted whilst also aiding dorsiflexion. In this way, the orthosis 1 aids the patient during all sta,,es of the walking motion. Furthermore, the orthosis 1 shown is considerably. more comfortable for the patient to wear than previously proposed devices as it does not extend beneath the foot and thus the weight of the patient does riot bear upon the orthosis 1 during walking.

6 A second embodiment of the invention is shown in Figure 5. This embodiment of the invention is primarily designed for use in conjunction with a shoe 9, and comprises an orthosis 1 of polypropylene, for example, and a single strap 11 provided at the end of the reinforcing means closest to the patient's leg, in use. Securing the strap 11 around the patient's lower leg and inserting the foot 5 and orthosis 1 within a shoe 9 provides an orthosis that is capable of resisting plantarflexion of the patient's foot. As an alternative to providing a strap, the upper end of the orthosis could be adhered to the patients lower leg.

If the straps of the orthosis of Figure 3 are removably attached to the rib 3, then the orthosis or FWure 3 could be conv'erted for use with a shoe, as shown in Figure 5, simply, be rernoving the lower strap.

As a further alternative that is not illustrated in the drawings, the straps could be dispensed with and the rib could then be adhered at least at the ends thereof to the Patient's lo-,,s-er leg and foot. The adhesive could be any, adhesive suitable for bonding articles to skill.

The orthosis of either embodiment may be coloured so that it can be matched to the skin colour of the patient, and may be provided in a variety of different shapes and sizes.

The orthosis may, be of a variety,' of different materials chosen to have a suitable resilience. For example, the orthosis could be of rubber, silicone, plastics, carbon fibre or of any7 other material apparent to persons skilled in the art. In a preferred example, the orthosis is of 35 shore silicone elastomer. The orthosis may be of a greater or lesser shore value depending upon the particular needs of the patient to which it is to be fitted.

It will be understood that the invention has been described herein by way of example only. and that modifications may, be made,s,ltiilii the scope of the invention.

7

Claims

1. An ankle-foot orthosis for resisting plantarflexion of a patient's foot, the orthosis comprising: a resilient rib locatable, in use, along and in abutment with at least a portion of the dorsal aspect of the patient's foot and at least a portion of the patient's lower leg, the orthosis comprising means for securing the rib to the patient's foot and lower leg.

2. An orthosis according to Claim 1, wherein the securing means comprises a first strap means securable about one end of the rib and the patient's lower leg, and a second strap means securable about the other end of the rib and the patient's foot.

An orthosis according to Claim 1, -,,,71ierein the securing means comprises a first strap means securable ahout one end of the rib and the patient's lower leg and a shoe for securing the other end of the rib to the patient's foot.

3.

4. An ortliosis according to Claim 1,,,,lierein the securing means comprises an adliesl-,.,e, at least end portions of the rib being adhered to the patient's lower leg and foot.

5. An orthosis according to any of Claims 1 to 4, k,herein the rib is of plastics.

6. An orthosis according to any of Claims 1 to 4, x,,licrein the rib is of silicone.

7. An orthosis according to any of Claims 1 to 5, wherein the rib is of polypropylene.

8.

An ortliosis according to any of Clairns 1 to 5, x,rberein the rib is of ortholene.

9. An ortliosis according to any of Claims 1 to 4,,lierein the rib is of carbon fibre.

10. An orthosis according to any preceding claim, wherein the orthosis is skin coloured.

An orthosis according to any preceding claim, wherein the orthosis is fabricated 5 by injection moulding.

12. An orthosis according to any of Claims 1 to 10, wherein the orthosis is stamped or pressed frorn sheet material.

13. A kit comprising a plurality of orthoses according to an), preceding claim, the orthoses being of varying size and shape for fitting to feet of different sizes and shapes.

14. A kit according to Claim 13, comprising differently coloured orthoses to allow the matching of the colour of the orthosis to the skin colour of the patient.

15. An orthosis substantially as hereinbefore described with reference to Figures 3, 4 and 5 of the accompanying figures.

-)o

16. A kit substantially as hereinbefore described.