WO2017098272A1

WO2017098272A1 - Joint protector

Info

Publication number: WO2017098272A1
Application number: PCT/GB2016/053899
Authority: WO
Inventors: Rami J ABBOUD; Tim Drew; Hannah LAWRIE
Original assignee: University Of Dundee
Priority date: 2015-12-11
Filing date: 2016-12-09
Publication date: 2017-06-15
Also published as: GB201521915D0

Abstract

A joint protector (1 ) includes an elongate portion of resilient sheet material (2) for fitting in the longitudinal direction across a joint (30) of a limb (32) or a digit, of a human or animal. Releasable fastening means (34) are provided at each end of the portion of sheet material (2) for fixing the joint protector to a limb or digit. The portion of sheet material (2) is provided with a plurality of transverse slits (14, 14a, 14'a, 22, 22a) through the thickness of sheet material. The joint protector (1 ) may be a knee or an elbow joint protector. At least two of the plurality of transverse slits may be provided as an opposed pair (14a, 14'a), each slit of the pair cutting through an outermost edge (16) of the portion of resilient sheet material and running towards its counterpart that runs from the outermost edge (16') at the other side of the resilient sheet material.

Description

Joint Protector

Field of the Invention

The invention relates to impact absorbing pad arrangements for joints such as knee or elbow joints. The invention is useful in providing protection during sports activities such as volleyball or basketball.

Background to the Invention

Impact absorbing pads for the knees or elbows are known and sold for use in a range of sports and leisure activities. They are beneficial in increasing player comfort and reducing the risk of injury, particularly in potentially high impact sports such as volleyball.

Typical pads are constructed from padded fabric and are held in place by elastic tension either of the fabric itself or of attached restraining straps. Such pads may have some disadvantages in use. They may be bulky and may not allow moisture from the skin to pass there through.

As they are typically used in sports activities the pads are subject to substantial forces in flexing. Pads may not fully accommodate joint flexion causing excessive pulling forces on the straps or other fixing means employed to hold the pads in place. Therefore in use, joint flexion may cause the pad and/or associated straps or other fixing means to ride over the skin, necessitating frequent repositioning.

Furthermore the displacement of a pad arrangement from the correct position may result in injury, if the pad is not in place to accept an impact.

There is therefore the need for alternative pad arrangements.

Description of the Invention

A joint protector comprising:

an elongate portion of resilient sheet material for fitting in the longitudinal direction across a joint of a limb or a digit, of a human or animal; and

releasable fastening means provided at each end of the portion of sheet material for fixing the joint protector to a said limb or digit; wherein the portion of sheet material is provided with a plurality of transverse slits through the thickness of sheet material.

For humans, the joint protector is especially useful as a knee or an elbow joint protector. Knees or elbows are subject to impact forces in a wide range of sporting and work activities. Alternatively the joint protector may be employed on wrist or finger joints. For animals the joint protector may be employed similarly, for example on the knee of a horse forelimb. The joint protector, and in particular the elongate portion of resilient sheet material is sized to suit the joint to be protected. Thus smaller protectors are made for finger joints than for a knee joint. As described hereafter in more detail, the plurality of transverse slits allows the portion of sheet material to extend longitudinally as a joint is flexed. Therefore the joint protector is generally employed in positions where the expected flexing of the joint will tend to cause tension in the sheet material, stretching it between the fastening means at each end of the portion of sheet material.

For finger, knee or elbow joints the portion of resilient sheet material is fitted across the outside of the joint. In the case of a wrist joint, which can bend inwardly or outwardly, the protector may be provided across either the inside (palm of the hand side) or the outside (back of the hand side) of the wrist, between lower arm and hand, depending on the part of the wrist to be protected.

The transverse slits are through the thickness of the sheet material i.e. they extend completely through the thickness of the sheet material, separating the material on one side of the slit from material on the other side of the slit. The transverse slits may be cuts made through the thickness of the sheet material, so that the sheet material to either side of the slit is in contact, when the sheet material is not under stretching forces. Alternatively the transverse slits may provide a gap when the sheet material is not under stretching forces.

The transverse slits allow the portion of sheet material to extend longitudinally when a joint is flexed i.e. bends from the straight to an angle or from an angle to a more acute angle. The sheet material portions at opposite edges of the slit can move apart relatively easily as the slit widens. When the joint is moved back to or towards the straight limb position the slit narrows or even closes again, as the sheet material is resilient.

This effect acts to mitigate the pulling action on the fastening means that is exerted as a joint provided with the protector is flexed. Displacement of the fastening means from the desired position, above and below the joint is avoided. More or fewer slits may be provided, to adjust the force required to extend the protector to a desired level, depending on the properties of the resilient sheet material employed. The use of the transverse slits may allow a stiffer, less easily stretched, sheet material to be employed successfully. Such stiffer materials may be more capable of impact absorption, when in a thinner sheet, than materials that stretch more easily.

The transverse slits also assist in reducing the bending force required to allow the resilient sheet material to conform to the shape of the joint and associated upper and lower limbs.

The releasable fastening means may include straps, transverse to the longitudinal direction of the resilient sheet material, for wrapping round the leg, elbow, finger or wrist. Typically one strap is provided for above the joint and one for below the joint. The straps may be adjustable in length. The straps may be provided with releasable fixings such as a buckle or press stud arrangements. Hook and loop releasable fastening materials such as Velcro® type products may be employed to close straps securely. The straps may be elasticated to provide grip by tension when fastened. The straps may be elasticated loops.

Straps may be fixed to the elongate portion of resilient sheet material by stitching or other bonding means such as adhesive or fusing together by melting. Conveniently straps are fixed by passing through one or more (for example two) longitudinally extending slits placed towards either end of the elongate portion of resilient sheet material.

The portion of resilient sheet material is provided with a plurality of transverse slits through the thickness of sheet material. The transverse slits are transverse to the longitudinal axis of the sheet material. They may be at right angles to the longitudinal axis of the sheet material. The slits may be rectilinear. The transverse slits may be of different types and arranged in different patterns.

Transverse slits may be provided in opposed pairs, each slit of a pair cutting through an outermost edge of the portion of resilient sheet material and running towards its counterpart that runs from the outermost edge at the other side of the sheet material. An opposed pair of transverse slits may be directly opposite each other. An opposed pair of transverse slits may be at right angles to the longitudinal axis of the sheet material or one or both slits may be at an angle away from the right angle. Both slits of an opposed pair of transverse slits may be at the same angle away from the right angle to the longitudinal axis or at different angles. An opposed pair of transverse slits may be at right angles to the longitudinal axis of the sheet material and directly opposite each other. The slits of an opposed pair of transverse slits do not meet as that would cut the portion of resilient sheet material in two. Opposed pairs of transverse slits have the advantage of allowing even extension of the sheet material as the slits will tend to open to the same extent, as a joint is flexed.

Alternatively or additionally transverse slits may be provided that are not in opposed pairs but are displaced longitudinally from other transverse slits. The transverse slit may cut through an outermost edge of the portion of resilient sheet material and run towards the outermost edge at the other side of the sheet material. Such transverse slits may be at right angles to the longitudinal axis of the sheet material or may be at angle away from the right angle. Alternatively or additionally transverse slits may be provided that are internal to the portion of resilient sheet material. An internal transverse slit does not extend to cut an outermost edge of the sheet material. An internal transverse slit may be at right angles to the longitudinal axis of the sheet material or may be at angle away from the right angle.

Where an end of a transverse slit is within the portion of resilient sheet material i.e. not cutting an outermost edge, then the slit may end in an aperture, for example a circular aperture. Apertures may extend through the thickness of the sheet material. Apertures have the advantage of avoiding tearing of the sheet material by propagation of the slit into the material, as the sheet material is stretched when flexing a joint in use. Thus for example internal transverse slits may have both ends ending in an aperture, which may be circular apertures.

Other slits, such as longitudinally extending slits for carrying straps, may also be provided with apertures at their ends.

Further apertures may be provided in the sheet material to aid ventilation and thereby reduce sweating of a wearer of the joint protector. Where an end of a transverse slit cuts an outermost edge of the portion of sheet material the sheet material may be shaped to avoid each side of the slit end being a sharp angle. For example the sheet may curve inwards towards the slit at either side of the slit. This may provide improved comfort in use and avoid snagging on clothing. Where transverse slits are provided in opposed pairs, each pair may be considered to divide the elongate portion of resilient sheet material into lobes. Each lobe is separated from the next by the opposed pair of transverse slits. Each lobe may include one or more internal transverse slits. Each lobe may include one or more transverse slits that do not have an opposed slit, the transverse slit or slits cutting through an outermost edge of the portion of resilient sheet material and running towards the outermost edge at the other side of the sheet material.

Each lobe may be of a different size and/or shape from another, having for example different length in the longitudinal direction and/or different width in the transverse direction. Lobes at an end of the elongate portion of resilient sheet material may be narrower near the location of the fastening means. For example the lobe may taper, so that the ends of the joint protector narrow near the location of the fastening means. This reduces the amount of material that may be in contact with the skin, where not required to protect against impact.

Conversely lobes that are positioned, in use, at a portion of limb that is expected to be subject to more significant impact, or impact from different directions, may be larger in area and/or may be made of a thicker sheet material. Lobes that in use extend around part of the angle of a flexed joint may be provided shorter in the longitudinal direction. Conveniently the joint protector or at least the elongate portion of resilient sheet material is symmetrical; at least in the longitudinal direction. This allows the joint protector to be fitted to a joint either way up, without any difference in fitting to the joint and associated limb, or in performance when in use. For example the joint protector may be divided by two pairs of opposed transverse slits into three lobes. A central lobe connecting to; two end lobes that carry the fixing means for fixing the joint protector to an arm or leg. More pairs of transverse slits may be provided dividing the joint protector into further lobes. A convenient example is a joint protector where the portion of sheet material is divided into five lobes; a central lobe connecting to two further lobes in each longitudinal direction. Four pairs of opposed transverse slits are provided. The central lobe may be larger in area or at least longer in the longitudinal direction than other lobes. The releasable fastening means is provided on the end lobes, the lobes at each end of the portion of sheet material. The releasable fastening means may be provided as straps for fixing the joint protector to an arm or a leg, for example. Between the end lobes and the central lobe are two intermediate lobes.

In use, the five lobed joint protector may be fitted, for example across a knee joint. It may also be sized to find use on other joints, for example an elbow joint. The central lobe may be positioned in use with its upper end, as fitted to the joint, at or below the apex of the joint.

In this arrangement, when fitted to a knee, the central lobe, and the two lobes beneath it (intermediate and end lobe), act to protect at least the lower part of the knee joint and the upper part of the shin. The two upper lobes (intermediate and end) protect the knee above and undergo the bulk of the flexing and extending in use. When the knee joint is flexed (bent) the opposed pairs of transverse slits; between the central lobe and the upper intermediate lobe; and between the upper intermediate lobe and the upper end lobe; allow the extension of the sheet material around the outside of the flexing joint. Other transverse slits, for example internal transverse slits, may be provided to aid longitudinal extension. As this form of the joint protector has a symmetrical arrangement of lobes, it may equally be worn on a joint the other way up. As an alternative to a joint protector with a more or less symmetrical arrangement of lobes a joint protector may be unsymmetrical with respect to the lobes provided. This type of arrangement may have some advantages, for example: where the impact or stress expected; or the amount of elongation and flexing required, at either side of a joint is different.

Thus a joint protector, for example for use on a knee joint, may have a lobe at one end that is longer, (when considered in the longitudinal in use - across a joint direction). The protector then has one or more (e.g. two or three) shorter in length lobes extending to the other end. Pairs of transverse slits, provided in opposed pairs, divide the elongate portion of resilient sheet material into lobes in the same way as for more symmetrical arrangements.

When used to protect a knee joint such an arrangement is fitted with the longer lobe covering the lower part of the leg i.e. covering at least the lower part of the knee joint, perhaps most or all of the knee cap; and preferably extending down to cover at least the upper part of the shin. In many activities, such as sports, a wearer may fall onto their knees with the lower part of the knee joint/upper part of the shin sustaining the greater impact. The longer lobe receives these impacts while the shorter lobes further up the joint/leg can also absorb impact whilst providing more elongation and flex capability. Conveniently one or more internal transverse slits such as described above may be provided in the longer lobe, typically towards the upper in use end of the lobe, i.e. between the middle of the lobe and the top of the lobe. The longer lobe may include a pocket containing a layer of padding, such as a resilient foam layer.

The elongate portion of resilient sheet material may be shaped so as not to be planar when in an unstressed condition. For example the elongate portion of resilient sheet material may be curved in a transverse direction. This can aid in conformance of the sheet material to the surface of a limb and associated joint.

The elongate portion of resilient sheet material may comprise a plastics foam material. An orthotic foam material can have advantages as it is impact absorbing yet relatively thin. An orthotic foam material i.e. a foam used for orthotic appliances is generally a thin and relatively stiffly resilient foam material suitable for absorbing impact without having bulky thickness,

Examples of foam materials that can be suitable for use in the invention can be selected from the group consisting of: polyethylene foams, EVA foams, closed cell memory foams and ethylene copolymer foams. Other suitable materials include latex rubber, neoprene, EPDM (ethylene, propylene, diene terpolymer) rubbers, silicone gels, and polyurethane gels. Thus commercially available materials include;

Plastazote: Polyethylene foam, may be moulded at temperatures between 85° and 140°;

Aortha: EVA foam mouldable between 120 ° and 140 °;

Aerosorb / Lunasoft. Closed cell memory foams; and

Evazote: Ethylene copolymer foam.

The elongate portion of resilient sheet material may comprise two or more layers of material, that may be the same or different. The layers making up the elongate portion of resilient sheet material may be bonded together, for example by an adhesive, or they may be attached one to another by fixing means such as stitching

Conveniently if two or more layers of material make up the elongate portion of resilient sheet material, they may be laminated together. The elongate portion of resilient sheet material may be shaped if desired. For example by bonding together two layers over a former, to provide shape to the sheet. Other layers may be added during or after moulding. For example, a sheet of a cloth material. The term "resilient sheet material" as used herein refers to the whole construction of the sheet including all the layers employed that are cut through by the transverse slits.

Brief Description of the Drawings

Figures 1 a, 1 b, 1 c and 1 d show a knee protector in perspective, front elevation, end elevation and plan views respectively;

Figure 2 shows the knee protector of figures 1 a to 1 d when fitted to a model leg;

Figure 3 shows an alternative knee protector; and

Figure 4 shows the knee protector of claim 3 in perspective. Detailed Description of Some Embodiments

Figure 1 a shows a joint protector 1 in perspective view. The joint protector 1 has a portion of orthotic foam laminate, resilient sheet material 2. The portion of resilient sheet material 2 is transversely curved for ready conformance to a limb and associated joint (see figure 2). The sheet material 2 has a longitudinal direction indicated by double headed arrow X. As more clearly seen in front view figure 1 b, or side view figure 1 c, the sheet material 2 is divided into five lobes 4, 6, 8, 10, 12 by four pairs of opposed transverse slits 14, 14'. The transverse slits 14, 14' each cut an outermost edge 16, 16' of the sheet material 2 and run towards the corresponding transverse slit approaching from the opposite outermost edge.

The outermost edges 16, 16' of the sheet material 2 are shaped at each transverse slit 14, 14' to curve inwards towards the slit at either side 18, 18' of the slit (only one instance marked on the drawings for clarity). The ends of the slits 14, 14' internal to the sheet of material 2 end in apertures 20, circular in this example. Also provided in this example are internal transverse slits 22, two in the central lobe 8, towards either end; one each in the intermediate lobes 6, 10; and one each in the end lobes 4, 12. The internal transverse slits 22 end in apertures 20 that are circular. End lobes 4, 12 each include a pair of internal longitudinal slits 24, ending in apertures 20. These slits 24 are for fixing means in the form of straps that may be passed there through (not shown here, see figure 2). Further circular apertures 26 are provided in central lobe 8 to aid ventilation. Figure 1 d shows the plan view from above the protector 1 , looking down on end 28.

Figure 2 shows in schematic perspective a joint protector 1 in use when fitted to a knee joint 30 of a model leg 32 that shows the musculature. Like parts are numbered the same as in figures 1 . In the figure the knee joint 30 is bent to demonstrate the extension of the portion of resilient sheet material 2. The protector 1 is fitted to the model leg 32 by means of straps 34 passing through longitudinal slits 24 and wrapping round the leg 32. Each strap 34 fixes to itself by overlapping and provision of Velcro type hook and loop fastenings. The portion of resilient sheet material 2 is fitted to the model leg 32 with the central lobe 8 and the two lobes beneath it (intermediate and end lobes 10,12), act to protect at least the front lower part 35 of the knee joint 30 and the upper part of the shin 36 from impact.

The two upper lobes (intermediate and end lobes 6, 4) protect the knee above from impact and undergo the bulk of the flexing and extending in use.

As can be seen in figure 2 as the knee joint is flexed (bent) the opposed pairs of transverse slits 14a, 14'a; between the central lobe 8 and the upper intermediate lobe 6; and between the upper intermediate lobe 6 and the upper end lobe 4; are opened, (in comparison with the closed positions shown in figures 1 ). This opening of the slits allows ready extension and flexing of the sheet material 2 around the outside of the flexing joint 30.

At the same time, internal transverse slits 22a; at the upper end of central lobe 8; in upper intermediate lobe 6; and upper end lobe 4; are also opened to further facilitate longitudinal extension and flexing of the sheet material 2. Straightening of the knee joint 30 will result in the slits 14a, 14'a and 22a tending to close. Further bending of the knee joint 30 will result in the slits 14a, 14'a and 22a tending to open further. Thus the straps 34 are less likely to be displaced from their position in comparison with a joint protector not provided with the slit arrangements shown.

The joint protector 1 is symmetrical and so may be worn either way up.

An alternative joint protector 1 for a knee joint is shown in figures 3 and 4. Figure 3 shows joint protector 1 in a rear view, i.e. the side that contacts a knee joint in use. Figure 4 shows the same joint protector in perspective view and flexed as if conforming to a bent knee in a similar way to the embodiment depicted in figure 2.

In the embodiment of figures 3 and 4, the sheet material 2 is divided into 4 lobes 4, 6, 8, 10 by three pairs of opposed transverse slits 14, 14'. The transverse slits 14, 14' each cut an outermost edge and run towards the corresponding transverse slit approaching from the opposite outermost edge in the same way as the slits in the embodiment of figures 1 and 2.

The ends of the slits 14, 14' internal to the sheet of material 2 end in circular apertures 20. Also provided in this example are three internal transverse slits 22, one each in lobes 6, 8 and 10.

Straps 34 are provided for fixing the protector 1 across a knee joint by wrapping round a leg and securing e.g. by hook and loop fastenings. The larger lobe 10 is provided with a pocket 36 filled with an additional layer 38 of resilient foam. The additional layer 38 of foam may be permanently fixed e.g. by adhesive in the pocket 36 or may be replaceable. Thus lobe 10 can be thicker and more shock absorbing than the other lobes 4, 6, 8, if desired. The flexed state of the protector 1 of figure 3 is shown in figure 4. Large lobe 10 provides a thick and substantially unitary padding, which can protect at least the front lower part of a knee joint and the upper part of a shin from impact, i.e lobe 10 can serve the same function as lobes 8, 10 and 12 in the embodiment of figure 2, The lobe 10 of figure 4 elongates and flexes at the knee joint by opening of its respective transverse slit 22. Further elongation and flexion of the joint protector 1 is accommodated by slits 14, 14' and the other transverse slits 22.

The lobe 10 of figure 4 may be provided with additional ventilation apertures if desired.

It may be understood that the present invention has been described above purely by way of example, and that modifications of detail can be made within the scope of the invention. Each feature disclosed in the description and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

Claims

CLAIMS:

1 . A joint protector comprising:

releasable fastening means provided at each end of the portion of sheet material for fixing the joint protector to a said limb or digit;

wherein the portion of sheet material is provided with a plurality of transverse slits through the thickness of sheet material.

2. The joint protector of claim 1 wherein the joint protector is a knee or an elbow joint protector.

3. The joint protector of claim 1 or claim 2 wherein at least two of the plurality of transverse slits is provided as an opposed pair, each slit of the pair cutting through an outermost edge of the portion of resilient sheet material and running towards its counterpart that runs from the outermost edge at the other side of the resilient sheet material.

4. The joint protector of claim 3 wherein the slits of the opposed pair of transverse slits are directly opposite each other.

5. The joint protector of claim 4 wherein the slits of the opposed pair of transverse slits are at right angles to the longitudinal axis of the sheet material.

6. The joint protector of any preceding claim further comprising at least one internal transverse slit that does not extend to cut an outermost edge of the sheet material.

7. The joint protector of any preceding claim further comprising at least one aperture at the end of a transverse slit.

8. The joint protector of any preceding claim where all the ends of transverse slits not cutting an outermost edge of the portion of resilient sheet material end in apertures.

9. The joint protector of any preceding claim further comprising at least one aperture in the resilient sheet material, not at the end of a slit.

10. The joint protector of any preceding claim wherein the releasable fastening means comprises straps transverse to the longitudinal direction of the resilient sheet material for wrapping round a said limb or digit.

1 1 . The joint protector of claim 10 wherein the straps are fixed by passing through one or more longitudinally extending slits placed towards either end of the elongate portion of resilient sheet material.

12. The joint protector of any preceding claim wherein the elongate portion of resilient sheet material is divided by two pairs of opposed transverse slits into three lobes, wherein each slit of each pair cuts through an outermost edge of the portion of resilient sheet material and runs towards its counterpart that runs from the outermost edge at the other side of the resilient sheet material.

13. The joint protector of claim 12, for use on a knee joint, wherein the lobes comprise: a lowest, in use, lobe that is longer in the longitudinal direction than the other three lobes.

14. The joint protector of claim 12 wherein the elongate portion of resilient sheet material is divided into five lobes by four pairs of opposed transverse slits, wherein each slit of each pair cuts through an outermost edge of the portion of resilient sheet material and runs towards its counterpart that runs from the outermost edge at the other side of the resilient sheet material.

15. The joint protector of claim 12 wherein the lobes comprise; a central lobe connecting to two further lobes in each longitudinal direction; and wherein the central lobe is longer in the longitudinal direction than other lobes.

16. The joint protector of any one of claims 12 to 15 wherein the releasable fastening means is provided on the end lobes, the lobes at each end of the portion of sheet material.

17. The joint protector of claim 12 wherein the elongate portion of resilient sheet material is divided by three pairs of opposed transverse slits into four lobes, wherein each slit of each pair cuts through an outermost edge of the portion of resilient sheet material and runs towards its counterpart that runs from the outermost edge at the other side of the resilient sheet material.

18. The joint protector of claim 17, for use on a knee joint, wherein the lobes comprise: a lowest, in use, lobe that is longer in the longitudinal direction than the other three lobes.

19. The joint protector of any preceding claim wherein the elongate portion of resilient sheet material comprises two or more layers of material laminated together.

20. The joint protector of any preceding claim wherein the elongate portion of resilient sheet material is curved in the transverse direction, when in an unstressed condition.