GB2370231A

GB2370231A - Ankle brace

Info

Publication number: GB2370231A
Application number: GB0122462A
Authority: GB
Inventors: Adrian David Bourne; Timothy Ian Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-12-22
Filing date: 2001-09-18
Publication date: 2002-06-26
Also published as: GB2370230A; GB0122462D0; GB0122460D0; GB0031460D0

Abstract

A shell (14) for an ankle brace (10) is substantially rigid and has an inner surface shaped to conform to an outer side surface of a person's leg (20) between an upper extent above the person's ankle bone and a lower extent below the person's ankle bone but above the base of the heel, and between a forward extent towards the front of the person's leg and a rearward extent towards the rear of the person's leg. The forward extent of the shell has a projecting region (54) for covering the person's anterior talofibular ligament (62). A second invention provides a through hole in the shell 34 having a size and shape generally identical to the shape of the protruding part 36 of the person's ankle bone.

Description

237023 1

TITLE Bracing of Ankles DESCRIPTION

This invention relates to orthopaedic devices and in particular to ankle braces and to shells used in ankle braces.

After injury to an ankle, such as a fracture or severe ankle sprain, it may be necessary to completely immobilize the ankle through the use of a moulded plaster or resin cast. However, 5 once the injury has been stabilized, recovery may be hastened by removing the moulded plaster or resin cast and using a removable functional walking brace so that the ankle can exercise during the healing. Also, if the injury is not severe enough to require complete immobilization, it may only be necessary to use a functional walking brace to stabilize the anlde against inversion, aversion and anterior subluxation, while still permitting the normal dorsiflexion and 10 plantarflexion movement of the ankle. Such braces may also be used to prevent an ankle injury, or used as a post-injury preventative measure.

A number of different designs of ankle brace are known. Most of then have a pair of relatively rigid side supports that are strapped around the leg to the sides of the lower leg and ankle. The side supports may also have an integral joining piece or a strap that extends under 15 the heel. There are deficiencies in the existing designs that the present invention (or at least specific embodiments of it) is aimed at alleviating.

Patent document EP-A 252121 describes an ankle brace (commercialized as the Aircast@), with an adjustable strap under the heel, that provides support for the calcanofibular and posterior talofibular ligaments. The side supports are somewhat domed to receive the 20 protruding parts of the ankle covering the ends of the ankle bone so as to avoid unduly high pressure in those regions. Nevertheless, it is still necessary for a substantial thickness of padding to be provided on the inner surfaces of the side supports. This has three main disadvantages: the padding reduces the stability of the brace; it is often not possible for the wearer to wear conventional shoes over the brace; and the padding causes problems with 25 sweating of the wearer's ankle. Patent document US-A 844094 describes a somewhat similar brace (commercialized as the Royce Formfit.

- 2 Patent document WO-A-99/63915 also describes a somewhat similar brace (commercialized as the Focused. Although the commercial product does not possess this feature, the patent document mentions that the outer side support may have an aperture to receive the tip of the fibular malleolus (the outer end of the ankle bone). There is no discussion of the size or 5 shape of the aperture, but the drawings in the document show a slightlyelliptical, vertically-

aligned hole of a size that would be too small to receive all of the protruding part of the body covering the ankle bone. Therefore, without sufficient padding, the edge of the hole would apply unduly high pressure to the protruding part of the ankle. However, as mentioned before, excessive padding leads to instability of the brace, bulkiness and problems with sweating. A 10somewhat similar arrangement is described in related patent document US-A-5902259. In one embodiment described in that document with reference to Figure 4 thereof, the inner side support is shown as having a relatively rigid piece extending downwardly from it and under the foot. This sets the vertical position of the side support. A small hole also appears to be shown in the side support, but substantially higher than the level of the ankle bone.

15Patent document US-A-4966134 describes an ankle brace (commercialized as the Lenox Hill Allsport Ankles), with an adjustable strap under the heel, that provides support for the calcanofibular and posterior talofibular ligaments. The side supports are recessed to accommodate the ends of the anlde bone. Although not shown or described in the patent document, the commercial product has a small forward projection from the front edge of the 20 outer side support, but this projection is substantially above the level of the centre of the recess.

Patent document US-A-5038762 describes an ankle brace (commercialized as the Malleoloc with an integral under-heel joining piece. The side supports are relatively narrow.

The inner side support extends upwardly over the inner end of the ankle bone and is likely to cause rubbing and unduly high pressure in that region. The outer side support extends upwardly 25 and forwardly of the outer end of the ankle bone and passes near the area of the anterior talofibular ligament. However, because of the integral under-heel joining piece, the vertical position of the brace is registered with respect to the heel, and so the brace will not supply any significant support to the anterior talofibular ligament unless it is of precisely the right size for the foot in question. Also, the width of the brace cannot be adjusted to fit different widths of 30 foot. This brace does not provide any significant support to the calcanofibular and posterior talofibular ligaments.

Patent document US-A4821743 describes a different kind of ankle brace (commercialized as the Caligaloc@) that has a single relatively rigid side support integral with a

- 3 base piece that extends underneath about half of the length of the wearer's foot, and strapping to hold the brace in place. The side support has a large hole so that it is well clear of and does not interfere with the region around the end of the ankle bone.

Patent documents FR-A-2766359, FR-A-276636O, DE-A-3909922 and DE-U8907464 5 describe somewhat similar arrangements, but with side supports on both sides of the ankle. In the case of FR-A-276636O, the two holes in either side support are either triangular, or circular, and in a variant described in FR-A-2766359, the device is articulated about the centres of the circular holes.

It is estimated that 85% of ankle sprains involve both the calcanofibular and anterior 10 talofibular ligaments in conjunction, whereas 70% of sprains due to inversion involve the anterior talofibular ligament alone. The treatment of a patient is also often delayed due to the need to allow the distress caused by swelling to reduce in order that an accurate diagnosis of the injury can be made. Alternatively, incorrect treatment is given because an inaccurate diagnosis, or no proper diagnosis at all, is made. Furthermore, none of the prior ankle braces mentioned 15 above provide support for both of these ligaments. The brace of US-A-5038762 and the Malleoloc" may provide some support for the anterior talofibular ligament alone if the brace is a very good fit, but no support for the calcanofibular ligament. Some of the other ankle braces provide support for the calcanofibular ligament, but not for the anterior talofibular ligament.

A first aspect of the present invention is concerned with providing a shell, or side 20 support, for an ankle brace, that can provide support for both of the ligaments mentioned above.

The first aspect of the invention provides a shell for an ankle brace, the shell being substantially rigid and having an inner surface shaped to conform to an outer side surface of a person's leg between an upper extent above the person's ankle bone and a lower extent below the person's ankle bone but above the base of the heel, and between a forward extent towards 25 the front of the person's leg and a rearward extent towards the rear of the person's leg, the forward extent of the shell having a projecting region for covering the person's anterior talofibular ligament. Because of the basic shape of the shell, it can provide support for the calcanofibular ligament and posterior talofibular ligament similarly to some of the known ankle braces, and because of the additional projecting region, the shell also provides support for the 30 anterior talobbular ligament. By using the shell of this aspect of the invention, it is therefore possible to provide treatment for both ligaments that are usually damaged in an ankle injury, together with the posterior talofibular ligament, even if the ankle is swollen and a full diagnosis cannot be made. (It should be noted, of course, that it is not a problem to provide support for a

ligament that is not in fact damaged, whereas it is a problem not to provide support for a ligament that is damaged.) A secondary advantage of this aspect of the invention is that hospitals, medically-qualified personnel and suppliers, for example, need only stock the shell of this aspect of the invention to enable treatment for all three ligaments, rather than needing to 5 stock different types of shell or brace for treatment of the different ligaments.

Preferably, the shell is shaped to engage with or around the protruding part of the person's body covering the ankle bone to register the shell with respect to the person's ankle bone. By registering the shell (and thus, in particular, the projecting part for supporting the anterior taloDbular ligament) with respect to the person's ankle bone, it is easier to obtain a 10 good fit than in the cases of the ankle brace of USA-5038762 and the Malleoloc=, because in those cases the part of the brace that can cover the anterior taloSbular ligament is registered vertically with respect to the base of the person's heel.

In the following description and in the claims, dimensions of the shell are specified for a

person having a shoe size of 9 (UK), 43 (European), 9/ (US male), 10l (US female). All 15 orientations are described as if the person wearing the ankle brace is in a standing position. It will be appreciated that the dimensions may be scaled for persons having other shoe sizes.

In order to provide good support for the anterior taloSbular ligament: À the projecting region preferably projects by a maximum distance of about 60 mm:t 15 mm (more preferably 10 mm, and even more preferably 5 mm) 20 from the tip of the person's ankle bone; À the position at which the projecting region projects to its maximum extent from the tip of the person's ankle bone is preferably below the tip of the person's ankle bone; À the level at which the projecting region projects forwardly to its maximum 25 extent is preferably about 23 mm 8 mm (more preferably 5 mm, and even more preferably 3 mm) below the level of the tip of the person's ankle bone; and/or À the position at which the projecting region projects to its maximum extent from the tip of the person's ankle bone is preferably inclined downwardly by about 30 30 i 10 (more preferably i 5 ) from the tip of the person's anlde bone.

Preferably, the shell has a through-hole having a size and shape generally identical to the size and shape of the periphery of the protruding part of the person's body covering the ankle bone, the shell being configured so that, with the hole snugly receiving the protruding part

5 - i.---

of the body, the inner surface of the shell conforms to the side surface of the person's leg, and the projecting region covers the person's anterior talofibular ligament. By providing a through-

hole to receive the protruding part of the person's body covering the ankle bone, rather than having a padded dome that covers that part of the body (as in the case of, for example, the 5 Aircast, Royce Formfit, Focus and Lenox Hill Allsport ankle braces), the shell can be made to be less bulky so that the person's normal shoe can be worn over the brace and sweating is less of a problem. By sizing and shaping the through-hole so that it is generally identical to the periphery of the protruding part of the person's body covering the ankle bone, the through-hole can register the shell with respect to the ankle bone without the shell applying unduly high 10 pressure to the protruding part of the body or without the need for large amounts of padding and the consequent problem with sweating, by contrast to the smaller holes that appear to be shown in WO- A-99/63915 and US-A-5902259, the larger hole of the Caligaloc brace, and the holes of FR-A-2766359 and FR-A-2766360 that cannot register those braces with the ankle bone because of the other rigid and non-adjustable features of the braces that hold them in place.

15 The level at which the projecting region projects forwardly to its maximum extent is preferably at about the same level as the lower extreme of the through-hole.

Although the through-hole feature described above is preferably used in combination with the feature to provide support for the talofibular ligament, it may also be employed independently whilst still providing similar advantages.

20 Accordingly, a second aspect of the present invention provides a shell for an ankle brace, the shell being substantially rigid and having an inner surface shaped to conform to a side surface of a person's leg between an upper extent above the person's ankle bone and a lower extent below the person's article bone but above the base of the heel, and between a forward extent towards the front of the person's leg and a rearward extent towards the rear of the 25 person's leg, the shell having a through-hole having a size and shape generally identical to the size and shape of the periphery of the protruding part of the person's body covering the ankle bone, the shell being configured so that, with the hole snugly receiving the protruding part of the body, the inner surface of the shell conforms to the side surface of the person's leg.

Preferably, the through-hole is non-circular, and more preferably is generally elliptical.

30 Preferably (and by contrast to the through-holes that appear to be shown in WO-A-99/63915 and US-A-5902259) with the major axis of the through-hole inclined upwardly and forwardly with respect to the person's leg.

In the case of a shell for the outer side of the person's leg: À the angle of inclination of the major axis of the through-hole is preferably about 15 i 10 (more preferably i 5 ); À the through-hole preferably has a major dimension of about 45 mm + 8 mm 5 (more preferably 5 mm, and even more preferably i 3 mm); and/or À the through-hole preferably has a minor dimension of about 34 mm i 8 mm (more preferably 5 mm, and even more preferably + 3 mm).

In the case of a shell for the inner side of the person's leg: À the angle of inclination of the major axis of the through-hole is preferably about 10 25 i 10 (more preferably i 5 ); À the through-hole preferably has a major dimension of about 56 mm i 8 mm (more preferably + 5 mm, and even more preferably 3 mm); and/or À the through-hole preferably has a minor dimension of about 45 mm it 8 mm (more preferably + 5 mm, and even more preferably 3 mm).

15 The shell may have a generally uniform thickness of, for example 3 mm to 4 mm. The inner surface of the shell may be provided with a layer of padding material, but if so the padding is preferably relatively firm and relatively thin so as not to reduce unduly the stability of the shell. The shell is preferably provided in combination with means for adjustably strapping the shell to the person's leg. Preferably, the shell is devoid of any feature extending beneath the 20 person's heel for non-adjustably registering the shell vertically with respect to the person's leg (by contrast to the Caligaloc and Malleoloc7 braces and one of the embodiments described in US-A-5902259).

A third aspect of the invention provides an ankle brace comprising a pair of shells and means for adjustably strapping the shells to the person's leg, at least one of the shells being in 25 accordance with the first and/or second aspect of the invention.

A fourth aspect of the invention provides an ankle brace comprising an inner shell according to the second aspect of the invention for the inner side surface of the person's leg, an outer shell according to the first or second aspect of the invention for the outer side surface of the person's leg, and means for adjustably strapping the shells to the person's leg.

30 The strapping means preferably includes: À an adjustable strap for extending under the person's heel between the lower extents of the shells;

À at least one adjustable strap for extending in front of the person's leg between the forward extents of the shells; and/or À at least one adjustable strap for extending behind the person's leg between the rearward extents of the shells.

5 Preferably, the ankle brace as a whole is devoid of any feature extending beneath the person's heel for non-adjustably registering the shells vertically with respect to the person's leg (by contrast to the Caligaloc and Malleoloc braces and one of the embodiments described in USA-5902259).

In the case where both shell have through-holes, the through-holes are preferably 10 dissimilar to each other, e.g. different sizes and/or different shapes.

In addition to providing the advantages mentioned above, the shells and braces according to the invention are comfortable to wear and can be worn with normal footwear.

Accordingly, by comparison with the known ankle braces, there will be less of a tendency for the user to remove the brace before treatment of an injury is complete.

15 A fifth aspect of the invention provides a method of preventing an injury to a person's ankle, comprising fitting a shell or an ankle brace, according to any of the first to fourth aspects of the invention, to the person's leg.

A sixth aspect of the invention provides a method of treatment of an injury to a person's ankle, comprising fitting a shell or an ankle brace, according to any of the first to fourth aspects 20 of the invention, to the person's leg.

A specific embodiment of the present invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view of the embodiment of the ankle brace fitted to a person's left ankle; 25 Figure 2 is an outer side view of the ankle brace fitted to the person's ankle; Figure 3 is an inner side view of the ankle brace fitted to the person's ankle; Figure 4 is a rear view of the ankle brace fitted to the person's ankle;

- 8 Figure 5 is an outer face view, on a larger scale, showing the outline of an inner shell of the ankle brace; Figure 6 is an outer face view, to a similar scale to Figure 5, showing the outline of an outer shell of the ankle brace; 5 Figure 7 is a vertical slice view, on a larger scale, taken along the section line 7-7 shown in Figure 6; Figures 8 to 11 are horizontal slice views, to a similar scale to Figure 7, taken along the section lines 8-8, 9-9, 10-10 and 11-11, respectively, shown in Figures 6 and 7.

Referring to the drawings, an ankle brace 10 comprises an inner shell 12, an outer shell 10 14 and strapping (shown schematically in the Figures 1 to 4 by dashed lines) for attaching the brace around a person's ankle. The strapping comprises a pair of front straps 16,18 that extend in front of the person's leg 20, a pair of rear straps 22,24 that extend behind the person's leg 20, and a lower strap 26 that extends under the person's heel 28. The effective lengths of the straps are independently adjustable, for example using Velcro for the attachment of the straps, 15 and at least the front straps 16,18 or the rear straps 22,24 are releasable to enable fitting and removal of the brace 10 to the person's ankle.

The shells 12,14 are formed of substantially rigid material, such as vacuum-formed plastics, injection-moulded plastics, glass reinforced plastics or graphite/glass reinforced plastics. Each shell has a generally uniform thickness of, for example, 3 mm to 4 mm. The 20 inner shell 12 has a through-hole 30 that receives the protruding part 32 of the person's body covering the inner end of the ankle bone. Similarly, the outer shell 14 has a through-hole 34 that receives the protruding part 36 of the person's body covering the outer end of the ankle bone.

Referring in particular to Figure 5, the outline of the inner shell 12 is generally rectangular, but with: (a) its forward extent 38 and rearward extent 40 both tapering inwardly, 25 below the level of the centre of the through-hole 30, towards the lower extent 42 of the inner shell 12; and (b) a slight necking of the width of the inner shell 12 just above the through-hole 30. The through-hole 30 has a size and shape generally identical to the size and shape of the periphery of the protruding part 32 of the person's body covering the inner end of their ankle bone. The through-hole 30 is generally elliptical with its major axis 44 inclined upwardly and 30 forwardly at an angle A of about 25 to the general centre line 46 of the inner shell 12. For a person having a shoe size of 9 (UK), 43 (European), 9 1/2 (US male), 101/2 (US female) and an

"average" ankle, it has been found that the length B of the major axis of the through-hole 30 should preferably be about 56 mm and that the length C of the minor axis of the through-hole 30 should preferably be about 45 mm.

The inner surface of the inner shell 12 is shaped to conform closely to the inner side S surface of the person's leg 20 that it covers (as will be described in more detail later in relation to the outer shell 14). Accordingly, when the inner shell 12 is applied under pressure to the inner surface of the person's leg 20, the through-hole 30 registers the inner shell 12 with respect to the person's ankle bone, and substantially the whole of the inner surface of the inner shell 12 contacts the person with a generally uniform pressure distribution, but without any substantial 10 pressure being applied to the protruding part 32 of the person's body covering the inner end of their ankle bone.

Referring in particular to Figures 6 to 11, the outline of the outer shell 14 is generally rectangular, but with: (a) its rearward extent 50 tapering inwardly, below the level of the centre of the through-hole 34, towards the lower extent 52 of the outer shell 14; (b) a slight necking of IS the width of the outer shell 14 at the level of the upper extreme of the through-hole 34; (c) a substantial projection 54 in the forward extent 46 of the outer shell 14 as will be described in more detail below; and (d) inward tapering of the forward extent, below the projection 54, towards the lower extent 52 of the shell 14. The through-hole 34 has a size and shape generally identical to the size and shape of the periphery of the protruding part 36 of the person's body 20 covering the outer end of their ankle bone. The through-hole 34 is generally elliptical with its major axis 56 inclined upwardly and forwardly at an angle D of about 15 to the general centre line 58 of the outer shell 14. For the person described above, it has been found that the length E of the major axis of the through-hole 34 should preferably be about 45 mm and that the length F of the minor axis of the through-hole 34 should preferably be about 34 mm.

25 As compared with the outline shape of the outer shell as generally taught by the prior art, the projection 54 is marked with a crossed pattern in Figures 2 and 6. The projection 54 projects forwardly to its maximum extent at a level which is at a distance G of about 23 mm below the centre of the through-hole 34, i.e. about level with the lower extreme of the through hole 34. The maximum distance H of the edge of the projection 54 from the centre of the 30 through-hole 34 is about 60 mm, at a downwardly inclined angle J of about 30 from the centre of the through-hole 34.

Referring in particular to Figures 7 lo 1l, the inner surface 60 of the outer shell 14 is shaped to conform closely to the outer side surface of the person's leg 20 that it covers. Thus,

- 10 as viewed in plan at various levels (Figures 8 to 11), the inner surface 60 of the outer shell 14 is concave and, in particular, is generally arcuate above the level of the through-hole 34.

However, at the level of the lower extreme of the through-hole 34 (Figure 11), the portion of the inner surface 16 in the region of the projection 54 is generally straight, or even slightly 5 convex, as viewed in plan.

Accordingly, when the outer shell 14 is applied under pressure to the outer surface of the person's leg 20, the through-hole 34 registers the outer shell 14 with respect to the person's ankle bone, and substantially the whole of the inner surface 60 of the outer shell 14 contacts the person with a generally uniform pressure distribution, but without any substantial pressure being 10 applied to the protruding part 36 of the person's body covering the outer end of their ankle bone. Importantly, the projection 54 covers the region 62 (see Figure 2) of the person's body covering the anterior talofibular ligament and therefore provides support for the anterior talofibular ligament.

Comparing Figures 5 and 6, although the inner shell 12 does not have such a 15 pronounced projection 54 as the outer shell 14, it should be noted that the forward extent 38 of the inner shell 12 does bulge forwardly below the level of the centre of the through-hole 30, more so than any of the known shells, in the area 55 marked with a crossed pattern in Figures 3 and 5. This bulging, in combination with the projection 54 on the outer shell 14 restricts up and down pivoting of the ankle and sideways rolling of the ankle so as to provide better locking of 20 the ankle.

When the brace 10 is initially fitted to the person, the inner and outer shells 12,14 are placed in position against the imer and outer sides, respectively, of the person's leg 20 and with the ankle portions 32,36 passing into the through-holes 30,34. Due to the general shape, size and configuration of the shells 12,24, they readily assume their correct positions. The straps 25 16,18,22,24,26 are then fastened and individually adjusted in length so that the shells apply light pressure to the ankle area when the ankle is in a relaxed state. A sock may be worn underneath the brace 10. Due to the thinness of the shells 12,14 and the lack of any large domed protrusions at the ends of the ankle bone, it is likely that a conventional shoe or boot may be worn over the sock and ankle brace. If it is desired to remove the ankle brace 10 temporarily, 30 for example to wash the foot, the front straps 16,18 may be released without disturbing the other straps 22,24,26, or the rear straps 22,24 may be released without disturbing the other straps 16,18,26, so that when the time comes to re-f t the brace it is necessary to re-fasten and adjust the two straps that were released, but no adjustment of the remaining straps is required.

- 11 If the brace 10 is initially applied when the ankle is swollen, then as the swelling subsides the straps 16,18,22,24,26 can be progressively shortened to maintain a good fit of the brace 10, with the parts 32,36 of the body covering the ends of the ankle bone progressively protruding further into the through-holes 30,34.

5 It will be appreciated that many modifications and developments may be made to the embodiment of the invention. For example, the sizes of the shells may be scaled for different sizes of ankle. Also, the shells 12,14 may be used singly, rather than as a pair. Furthermore, although the through-holes 30,34 are preferred, they may be omitted in one or both of the shells 12,14. Moreover, although the projection 54 to cover the talofibular ligament is preferred, it 10 may be omitted. Also, the inner surfaces of the shell 12,14 may be provided with a layer of padding material, but preferably the padding is relatively firm and relatively thin so as not to reduce unduly the stability of the shell and not to increase unduly the bulkiness of the brace.

The shells 12,14 may be formed with additional perforations through their thickness to allow the user's leg/ankle to breathe and thus reduce problems of sweating, and any padding may likewise IS be perforated or porous. Some features of the shape and size of the shells 12,14 may be modified. For example, the height of the shells 12,14 above the holes 30, 34 may be varied considerably. Also, the shape and extent of the shells 12,14 below the holes 30,34 may be varied, for example as shown by the dotted lines 64,66 in Figures 3 and 2, respectively. It should be noted that the embodiment of the invention has been described

above purely 20 by way of example and that many other modifications and developments may be made thereto within the scope of the present invention.

Claims

- 12 CLAIMS

1. A shell for an ankle brace, the shell being substantially rigid and having an inner surface shaped to conform to an outer side surface of a person's leg between an upper extent above the person's ankle bone and a lower extent below the person's ankle bone but above the base of the heel, and between a forward extent towards the front of the person's leg and a 5 rearward extent towards the rear of the person's leg, the forward extent of the shell having a projecting region for covering the person's anterior talofibular ligament.

2. A shell as claimed in claim 1, wherein the shell is shaped to engage with or around the protruding part of the person's body covering the ankle bone to register the shell with respect to the person's ankle bone.

10

3. A shell as claimed in claim 2, wherein the projecting region projects by a maximum distance of about 60 mm it 10 mm from the tip of the person's ankle bone.

4. A shell as claimed in claim 2 or 3, wherein the position at which the projecting region projects to its maximum extent from the tip of the person's ankle bone is below the tip of the person's ankle bone.

15

5. A shell as claimed in any of claims 2 to 4, wherein the level at which the projecting region projects forwardly to its maximum extent is about 23 mm 5 mm below the level of the tip of the person's ankle bone.

6. A shell as claimed in any of claims 2 to 5, wherein the position at which the projecting region projects to its maximum extent from the tip of the person's ankle bone is inclined 20 downwardly by about 30 t 5 from the tip of the person's ankle bone.

7. A shell as claimed in any of claims 2 to 6, wherein the shell has a through-hole having a size and shape generally identical to the size and shape of the periphery of the protruding part of the person's body covering the ankle bone, the shell being configured so that, with the hole snugly receiving the protruding part of the body, the inner surface of the shell conforms to the 25 side surface of the person's leg, and the projecting region covers the person's anterior talofibular ligament.

8. A shell as claimed in claim 7, wherein the level at which the projecting region projects forwardly to its maximum extent is at about the same level as the lower extreme of the through hole.

- 13

9. A shell for an ankle brace, the shell being substantially rigid and having an inner surface shaped to conform to a side surface of a person's leg between an upper extent above the person's ankle bone and a lower extent below the person's ankle bone but above the base of the heel, and between a forward extent towards the front of the person's leg and a rearward extent 5 towards the rear of the person's leg, the shell having a through-hole having a size and shape generally identical to the size and shape of the periphery of the protruding part of the person's body covering the ankle bone, the shell being configured so that, with the hole snugly receiving the protruding part of the body, the inner surface of the shell conforms to the side surface of the person's leg.

10 10. A shell as claimed in any of claims 7 to 9, wherein the throughhole is non-circular.

11. A shell as claimed in any of claims 7 to 10, wherein the through-hole is generally elliptical.

12. A shell as claimed in claim 11, wherein the major axis of the through-hole is inclined upwardly and forwardly with respect to the person's leg.

15

13. A shell as claimed in claim 12, for the outer side of the person's leg, wherein the angle of inclination of the major axis of the throughhole is about 15 i 5 .

14. A shell as claimed in any of claims 10 to 13, for the outer side of the person's leg, wherein the throughhole has a major dimension of about 45 rum 5mm.

15. A shell as claimed in any of claims 10 to 14, for the outer side of the person's leg, 20 wherein the through-hole has a minor dimension of about 34 mm:t 5mm.

16. A shell as claimed in claim 12, for the inner side of the person's leg, wherein the angle of inclination of the major axis of the throughhole is about 25 5 .

17. A shell as claimed in any of claims 10 to 12 and 16, for the inner side of the person's leg, wherein the through-hole has a major dimension of about 56 mm it 5mm.

25

18. A shell as claimed in any of claims 10 to 12, 16 and 17, for an inner side of the person's leg, wherein the through-hole has a minor dimension of about 45 mm 5mm.

19. A shell as claimed in any preceding claim, wherein the shell has a generally uniform thickness.

- 14

20. A shell as claimed in any preceding claim, wherein the inner surface of the shell is provided with a layer of padding material.

21. A shell as claimed in any preceding claim, in combination with means for adjustably strapping the shell to the person's leg.

5

22. A shell as claimed in any preceding claim, wherein the shell is devoid of any feature extending beneath the person's heel for nonadjustably registering the shell vertically with respect to the person's leg.

23. A shell for an ankle brace for an inner side of a person's leg, substantially as described with reference to Figures 1 to 5 of the drawings.

10

24. A shell for an ankle brace for an outer side of a person's leg, substantially as described with reference to Figures 1 to 4 and 6 to 11 of the drawings.

25. An anlde brace comprising an inner shell as claimed in any of claims 1 to 12 and 16 to 23, for the inner side surface of the person's leg, an outer shell as claimed in any of claims 1 to 15, 19 to 22 and 24, for the outer side surface of the person's leg, and means for adjustably 15 strapping the shells to the person's leg.

26. An ankle brace as claimed in claim 25, wherein the strapping means includes an adjustable strap for extending under the person's heel between the lower extents of the shells.

27. An ankle brace as claimed in claim 25 or 26, wherein the strapping means includes at least one adjustable strap for extending in front of the person's leg between the forward extents 20 of the shells.

28. An ankle brace as claimed in any of claims 25 to 27, wherein the strapping means includes at least one adjustable strap for extending behind the person's leg between the rearward extents of the shells.

29. An ankle brace as claimed in any of claims 25 to 28, wherein the brace is devoid of any 25 feature extending beneath the person's heel for non-adjustably registering the shells vertically with respect to the person's leg.

30. An ankle brace as claimed in any of claims 25 to 29, wherein each shell is as claimed in claim 7 or 9 or any claim dependent thereon, and wherein the through-holes of the shells are dissimilar to each other.

- 15

31. An ankle brace as claimed in claim 30, wherein the through-holes have different sizes.

32. An ankle brace as claimed in claim 30 or 31, wherein the throughholes have different shapes.

33. An ankle brace substantially as described with reference to the drawings.

5

34. A method of preventing an injury to a person's ankle, comprising fitting a shell or an ankle brace as claimed in any preceding claim to the person's leg.

35. A method of preventing an injury to a person's ankle, substantially as described with reference to the drawings.

36. A method of treatment of an injury to a person's ankle, comprising fitting a shell or an 10 ankle brace as claimed in any of claims 1 to 23 to the person's leg.

37. A method of treatment of an injury to a person's ankle, substantially as described with reference to the drawings.