COMPRESSION STOCKING

Abstract

The present invention relates to a compression stocking (10) which is divided into at least two parts, making it easier to put the stocking on and to take it off. A first part (12) has a foot portion (16), an ankle portion (18) which extends above the malleolus 14, and a first overlap portion (24) which is above the ankle portion, and is so formed as to exert in use a pressure which is reduced compared to a pressure exerted by the ankle portion. A second part (30) is tubular and has a second overlap portion (32) and a leg portion (34) which extends in use up the leg from the overlap portion to surround at least part of the lower leg.

In use the first overlap portion is able to be placed within the second overlap portion, the compression stocking providing a pressure which reduces progressively up the leg.

An outer surface of the first part and an inner surface of the second part are formed in a manner which provides a sufficiently low coefficient of friction to enable the compression stocking to be put on by putting the first part on first, and then drawing the second part over the first part and pulling it up the leg to bring the second overlap portion into position around the first overlap portion, so that passage of the second part over the foot and ankle is facilitated by the first part.

Claims

1. A compression stocking comprising a first part comprising: a foot portion configured to be worn on the foot; an ankle portion configured to extend above the malleolus in use; and a first overlap portion above the ankle portion, the first overlap portion being formed to exert in use a pressure which is reduced compared to a pressure exerted by the ankle portion, and a second part which is tubular and comprises a second overlap portion and a leg portion which extends in use up the leg from the overlap portion to surround at least part of the lower leg, so that in use the second overlap portion is able to be placed around the first overlap portion, the compression stocking providing a graduated pressure profile, and wherein an outer surface of the first part and an inner surface of the second part are formed in a manner which provides a low coefficient of friction between them, enabling the compression stocking to be put on by putting the first part on first, and then drawing the second part over the first part and pulling it up the leg to bring the second overlap portion into position around the first overlap portion, so that passage of the second part over the foot and ankle is facilitated by the first part.

2. A compression stocking as claimed in claim 1 provided with a set of instructions to a user directing the user to put the stocking on by putting the first part on first, and then drawing the second part over the first part.

3. A compression stocking as claimed in claim 1 or claim 2 in which the first part is provided with a visible external marking, exposure of which indicates when the second part has been drawn to its required position.

4. A compression stocking as claimed in claim 3 in which the marking is disposed below the first overlap portion and has a certain vertical extent, the marking changing in a progressive manner over this vertical extent so that as the second part is drawn up the leg the exposed part of the marking gives a basis for judging how much further the second part needs to be drawn to reach its required position.

5. A compression stocking as claimed in claim 4 in which the marking comprises a pair of lines or edges which converge upwardly, and which meet at the level which is to be reached by a lower edge of the second part.

6. A compression stocking as claimed in any preceding claim in which the first part is of closed toe form.

7. A compression stocking as claimed in any preceding claim in which the first overlap portion has a lower edge which is above the malleoli in use.

8. A compression stocking as claimed in claim 7 in which the lower edge of the first overlap portion is between 5 and 10 centimetres above the summit of the medial malleolus in use.

9. A compression stocking as claimed in any preceding claim in which the lower edge of the first overlap portion is between 6 and 8 centimetres above the summit of the medial malleolus in use.

10. A compression stocking as claimed in any preceding claim in which, in use, the first and second overlap portions contribute substantially equal pressures.

11. A compression stocking as claimed in any of claims 1 to 9 in which, in use, the first and second overlap portions contribute different pressures.

12. A compression stocking as claimed in any preceding claim in which the second overlap portion is deeper, in a direction extending along the leg in use, than the first overlap portion.

13. A compression stocking as claimed in claim 12 in which the second overlap portion is between 0.5 centimetres and 1.5 centimetres deeper than the first overlap portion.

14. A compression stocking as claimed in any preceding claim in which an area of the foot portion in which is in the vicinity of the Achilles heel in use is formed to have a lower elastic stiffness than material surrounding it, and so to stretch preferentially during dorsiflexion.

15. A method of putting on a compression stocking, comprising forming the compression stocking in at least two parts, a first part of the compression stocking comprising a foot portion configured to be worn on the foot; an ankle portion configured to extend above the malleolus in use; and a first overlap portion above the ankle portion, the first overlap portion being formed to exert in use a pressure which is reduced compared to a pressure exerted by the ankle portion, and a second part of the compression stocking being tubular and comprising a second overlap portion and a leg portion which extends in use up the leg from the overlap portion to surround at least part of the lower leg, the method comprising putting the first part on first, and then drawing the second part over the first part and pulling it up the leg to bring the second overlap portion into position around the first overlap portion, so that passage of the second part over the foot and ankle is facilitated by the first part.

16. A method as claimed in claim 14 further comprising forming the first and second parts in such a manner that friction between them as the second part is drawn over the first part is low enough to enable application of the second part with light manual force.

17. A compression stocking substantially as herein described with reference to, and as illustrated in, any of the accompanying drawings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0038] FIG. 1 shows the medial aspect of two parts forming a compression stocking according to the present invention;

[0039] FIG. 2 is similar to FIG. 1 but shows the two parts positioned as in use;

[0040] FIG. 3 is an enlarged scrap view, in section, of an overlap region of the compression stocking;

[0041] FIG. 4 shows the medial aspect of a first part of a further compression stocking embodying the present invention;

[0042] FIG. 5 is a side view of still a further compression stocking embodying the present invention;

[0043] FIG. 6 is a side view of yet a further compression stocking embodying the present invention; and

[0044] FIG. 7 is a view from the rear of yet another compression stocking embodying the present invention.

[0045] Compression stocking 10 illustrated in FIGS. 1 and 2 is formed in two separate parts, in order to facilitate putting it on and taking it off.

DETAILED DESCRIPTION

[0046] A first part 12 is shaped and sized in the manner of a sock to be worn upon the foot of a user and to extend above the malleolus, whose profile is indicated at 14. The first part 12 has a foot portion 16 and an ankle portion 18. In the present example the foot portion 16 incorporates a closed toe region 20. It is also shaped to provide a bulbous heel region 22. The ankle portion is tubular and leads continuously to a tubular first overlap portion 24.

[0047] A second part 30 of the compression stocking is separately formed from the first and is of tubular form, having at its lower end (terms such as upper, lower and vertical are to be understood, throughout this description and the appended claims, to be used with reference to the orientation of the compression stocking when it is worn by a standing user) a second overlap portion 32, above which is a leg portion 34. In the present example the leg portion is to surround the shin and calf, extending to a level just below the user's knee. At its upper edge it carries a high friction welt 36 to resist any tendency for the compression stocking to move down the leg during physical activity.

[0048] When the compression stocking 10 is correctly worn on the leg (FIG. 2), the first overlap portion 24 is within the second overlap portion 32.

[0049] The illustrated compression stocking 10 is a graduated stocking. The pressure it exerts decreases in a direction up the leg, in order to urge blood upwardly and assist venous return flow. Discontinuities in the pressure profile are undesirable since they may impair this function. In the region 24/32 where the first and second parts of the stocking overlap, the pressures they each contribute due to their elasticity are added, so that if these regions of the stocking parts had the same elastic properties as the remainder of the compression stocking 10 then pressure in this overlap region could be excessive. To avoid this, one or both of the overlap portions 24 and 32 contribute a reduced pressure in comparison to the adjacent regions of the compression stocking 10, so that the total pressure exerted by the overlap portions 24 and 32 together is approximately equal to the pressures exerted by those adjacent regions. This pressure reduction may be because the material of the overlap region(s) is less stiff than the neighbouring material and/or because the overlap regions are, when unstressed, larger in circumference than the neighbouring regions, so that they are stretched less when on the leg.

[0050] In the present embodiment, the first overlap portion is elastically less stiff, in the circumferential direction, than the neighbouring portion of the ankle region 18 of the first part 12 of the stocking. The second overlap portion 32 is elastically less stiff, in the circumferential direction, than the neighbouring portion of the calf region 18 of the second part 30 of the stocking. In the present embodiment each of the overlap portions 24, 32 contributes approximately half of the total pressure in the overlap region. This proportion may be different in other embodiments. In some embodiments the pressure exerted by the overlap portion 24 of the first part 12 is larger than the overlap portion 32 of the second part 30, in order to increase friction between the overlap portion 24 and the skin beneath.

[0051] The illustrated stocking is manufactured by knitting and the knitted fabric is thinner and less stiff in the overlap regions 24, 32. This is advantageous in that the two layers together in the overlap region are not excessively thick or bulky, but instead are comparable in thickness to the adjacent regions of the stocking above and below.

[0052] The result is that the pressure exerted on the leg varies generally in the desired, graduated, manner along the length of the leg, without a dramatic discontinuity at the overlap region 24/32. The sum of the pressures contributed by the two overlap parts 24, 32 where they overlap is roughly equal, at the lower end of this overlap region, to the pressure exerted by adjacent material of the ankle portion 18 alone, and is roughly equal, at the upper end of the overlap region to the pressure exerted by adjacent material of the leg portion 34 alone.

[0053] The compression stocking 10 is intended and adapted to be put on in the following manner.

[0054] The first part 12 is put on before the second part 30. Drawing the first part 12 onto the foot and ankle is a relatively straightforward process because it extends a limited distance above the ankle, so the length of the material being drawn over the foot is small compared to a one-piece stocking. It is not desirable to place excessive tension on the overlap portion 24, which is of relatively light material, but the positioning of the overlap 24/32 ensures that there is ample material below this portion, and above the ankle, by which the first part 12 can be grasped.

[0055] The wearer then flexes the ankle joint a few times (i.e. carries out dorsiflexion and plantar extension) which helps to settle the first part 12 in a stable position on the foot and ankle.

[0056] Once the first part 12 is in place, the second part 30 is put on. This involves drawing the second part 30 over the first part 12. During this process the foot and ankle are protected from rubbing by the first part 12. The first part 12 helps the second part 30 to slide over the foot and ankle and into position higher up the leg. The second part 30 slips easily over the first part 12, due to the properties of the fabrics from which they are formed. In addition the first part 12 covers the toes, toenails and other irregularities of the foot, providing a smooth shape for the second part 30 to slip over and preventing catching of the second part 30 on such irregularities. The first part 12 therefore serves two functions. It is not only an inherent part of the compression stocking, but it also serves to facilitate the application of the second part 30.

[0057] When removing the compression stocking 10, the second part 30 is removed before the first part 12. The first part 12 again helps the second part 30 to slide over the foot and ankle, protecting the skin. Typically the second portion, rather than sliding over the lower calf and shin, is rolled down over itself, so that by the stage at which it is drawn off the ankle and foot it has been turned inside out.

[0058] The parts 12, 30 of the compression stocking 10 are formed in such a manner that the coefficient of friction between surfaces of the stocking as it is put on and taken off is low. When putting on the stocking 10, the inner surface of the second part 30 slips easily over the outer surface of the first part 12. When taking the stocking 10 off, the second part 30 is typically turned back upon itself, and in this process the outer surface of the second part 30 is drawn over itself and over the outer surface of the first part 12, these surfaces again being formed in a manner which enables them easily to slip without need of excessive manual force.

[0059] The relevant coefficient of friction between the surfaces of the stocking may be characterised in that it is low enough to enable the second part 30 to be drawn over the first part 12 and into its required position with only moderate manual force. Alternatively the friction may be characterised in that it is not sufficient to cause the first part 12 to be drawn along the leg as the second part 30 is pulled over it.

[0060] The surfaces of the parts 12, 30 of the compression stocking 10 may be shiny. They may be silky. They may be smooth. They may be low friction surfaces. They may be gloss, as opposed to matt, surfaces.

[0061] The material of the parts 12, 30 of the compression stocking 10 may be manufactured by known tubular knitting techniques. Suitable elastic materials include fibres of natural rubber, spandex, nylon and cotton, and elastane, which may be used in combination. Knitted elastic materials are used in the present embodiment.

[0062] As noted above, it is desirable to resist slippage of one overlap portion 24 relative to the other overlap portion 32. The inventor has established that this can be achieved even without any fasteners and despite the low coefficient of friction between the first and second parts 24, 32. Once the compression stocking 10 is correctly worn upon the leg, it is flexure of the joints and muscle activity that tend to cause any slippage. But consider the forms of motion involved. Dorsiflexionthat is, turning the foot about the ankle joint in the direction indicated by arrow 38 in FIG. 2may be expected to elongate the underside of the first part 12, creating tension acting in the direction of arrow 40 tending to move the rear of the ankle portion downward. But in practice tension in the material along the sole of the foot is reacted through the engagement of the bulbous heel portion 22 with the user's heel. In this way the heel portion 22 acts in the manner of a tether, so that any vertical movement tends to be limited to the region of the arrow 40 above the heel. Activity of the calf muscle produces essentially horizontal movement (changes in leg circumference) as suggested by arrow 42 in FIG. 2, but due to its direction this does not tend to cause slippage in the overlap region. Vertical movement of the first part 12 in the area indicated by arrow 40 is resisted by friction between the first part 12 and the skin of the wearer, and not solely by friction between the two parts of the stocking 10.

[0063] The position of the overlap region 24/32 is considered to have a bearing on the stability of the overlap 24, 32. The greatest vertical movement is experienced around the area of the Achilles tendon, at the level of the ankle, so if the overlap is too close to the ankle its stability may be impaired, tending to pull the overlap apart. Vertical movement of the compression stocking 10 in this area is found in practice to diminish in a direction upward from the ankle, so that an overlap region high up the lower leg can be expected to be more stable. But if it is too high up the leg then the difficulty of putting on the first part 12 may be increased due to the extra length of this part. Also an overlap high up the lower leg may be regarded as cosmetically unacceptable. In the present embodiment the lower edge of the first overlap portion 24 is sited approximately 6 to 8 centimetres above the summit of the medial malleolus 14. This dimension is indicated by arrow 44 in FIG. 1. It results in a first portion of small enough length to be easily put on, and provides stability of the overlap. Also the ankle portion 18 and the first overlap portion 24 are together deep enough to be easily grasped to pull the first part 12 onto the foot. The most critical area for compression in treatment of venous ulcers is the portion of the ankle just above the malleoli, as this is where most venous ulcers occur. The suggested positioning of the overlap region provides a run of continuous material in this region, to ensure good functional compression, the overlap region 24, 32 being above this critical area of the ankle.

[0064] The dimension 44 may be varied in other embodiments.

[0065] The depth of the overlap zone (arrow 46 in FIG. 1) is approximately 5 centimetres in the present embodiment, but could be varied in other embodiments. FIG. 3 shows a detail of the overlap in a form which is somewhat stylised. The material forming the overlap is depicted in section and it can be seen that at a transition between the first overlap portion 24 and the ankle portion 18, a ridge 50 is present. In the present embodiment this is a result of the knitting process used to form the compression stocking 10, although it could take other forms. It somewhat deforms the material of the second overlap portion 32 in a region indicated at 52, and tends to resist slippage in the overlap region. Note also that the second overlap portion 32 is slightly larger in depth than the first overlap portion 24, providing a band 54 (see FIG. 3) of the second overlap portion 32 which extends onto the ankle portion 18. This helps to ensure, in the event that the overlap should be pulled apart slightly, that there is not a local loss of pressure which could impair the function of the compression stocking 10.

[0066] FIG. 7 represents an optional development of the compression stocking 10 according to an embodiment of the invention. This includes an area 301 of fabric which is elastically less stiff than the fabric around it. The area 301 is disposed at the rear of the lower leg in use, and more specifically in the present example it is in the region of the mid aspect of the Achilles tendon. The area 301 is able to stretch more easily (i.e. with less tension) than surrounding material along the direction of arrow 40 in response to dorsiflexion, and due to its low stiffness it serves to reduce any resultant tension referred to the first overlap zone 24 tending to move that zone of the stocking 10 along the leg. In this way the area 301 helps to prevent movement of the first overlap zone 24 and stabilise the overlap. The area 301 can be formed by local variation of the weave of the stocking. In FIG. 7 the area 301 is depicted as a narrow diamond shape, but other shapes could be used.

[0067] When putting the compression stocking 10 on, the second part 30 needs to be pulled far enough up the leg to bring the overlap portions 24, 32 into their proper positions, and no further. To facilitate this the first part 12 may be provided on its outer surface with a marking which is revealed as the second part 30 is drawn up the leg, providing a visual indication when the required position has been reached. This marking may be positioned below the desired level of the lower edge of the second part 30, so that it begins to be revealed somewhat before the desired position is achieved. It can vary over its vertical extent in a manner which enables the user to judge how much further the second part 30 needs to be drawn up the leg to achieve the required position. In the embodiment illustrated in FIG. 4, the marking 60 takes the form of a triangle having sides 62, 64 which converge upwardly and which meet just below the lower edge of the first overlap portion 24. When the apex of this triangle is visible, the user knows that the second part 30 is properly positioned. The marking could take a variety of other forms. The marking 60 is in this embodiment disposed on the medial aspect of the leg, which is advantageous both in that (a) it is easily viewed by the wearer as the stocking is put on and (b) being directed toward the other leg, it is visually inconspicuous in use.

[0068] The formation of the foot portion 16 with a closed toe 20 is advantageous in that the toes are covered while the second part 30 of the stocking is pulled over them. In this way it is ensured that the toes do not catch on the second part, which facilitates the donning of part 30 and which could additionally or alternatively cause damage to the stocking. Nonetheless the present invention may be implemented with an open toe form of stocking.

[0069] In an alternative embodiment of the invention (not illustrated) a light, low compression, low friction foot sock may be provided in addition to the first and second parts 12, 30. This foot sock would be put on before the first part 12, typically extending just above the malleolus. The first part 12 is the put on over the ankle sock, which thus serves to reduce the effort needed to pull on the first part 12 and to prevent catching on the toenails etc. This embodiment may be especially easy for users to put on, and suited to those who struggle most to put on a conventional compression stocking. This embodiment is also well suited to the use of an open-toed first part 12.

[0070] The compression stocking 10 illustrated in FIGS. 1 and 2 terminates below the knee, but the present invention may be embodied in a compression stocking which extends to the thigh. Such an embodiment 100 is illustrated in FIG. 5, this version being once more formed in two partsa first part 112 and a second part 130, with the overlap between them being a short distance above the ankle. However FIG. 6 shows an embodiment in which, to further facilitate putting compression stocking 200 onto the leg, it is broken into first, second and third parts 212, 230, 270. In this case the sequence for putting on the compression stocking 200 involves putting the first part 212 onto the foot and ankle, then putting the second part 230 onto the lower leg, then putting on the third part 270 which extends to the thigh region. The second and third parts 230, 270 overlap in a region 272.

[0071] In the illustrated embodiments the material forming the first and second overlap regions 24, 30 is the same as the material of the compression stocking 10, save for the knit pattern that provides a reduced modulus of elasticity in these regions. But in other embodiments the overlap regions 24, 30 may be formed in a manner which increases friction between the overlap regions. This may be achieved by a coating on one or both of the facing surfaces at the overlap, or through changes in the weave of the fabric or its material in these areas.

[0072] In still other embodiments the compression provided by the first part 12 to the foot of the wearer may be relatively low, with greater compression being applied by the second part 30 to the wearer's leg.

[0073] Individual parts can be manufactured in different sizes, and made to measure, for different diameters of the various parts of the leg and for different leg lengths. Some patient's legs are of highly abnormal shape and compression stockings need to be fitted based on measurements at the foot, ankle, mid-calf and upper calf. Forming the compression stocking in two parts makes possible different permutations of stock parts to obtain a correctly fitting stocking.

[0074] The simple multi-part designs illustrated herein eliminate the need for any bulky joiners or fasteners and therefore preserve the cosmetic acceptability of the garment, which is important for patient compliance.

[0075] Compression stockings require laundering, and over time this reduces their elasticity and functionality. An advantage of the illustrated embodiments is that the parts of the compression stocking 10, 100, 200 can be washed separately. The first part 12, 112, 212 is expected to require more frequent laundering because it encases the foot, but it is of less importance in terms of providing limb compression than the second part 30, 130, 230, which can be laundered much less often. This can increase the functional life of the compression stocking.

[0076] The compression stocking 10 will typically provide a pressure which, at its greatest, is more than 1.9 kPa. The compression stocking 10 may be in any of the compression classes mentioned above with reference to the prior art. That is, it may be: [0077] light compression1.9 to 2.3 kPa (14 to 17 mmHg); [0078] medium compression2.4 to 3.2 kPa (18 to 24 mmHg) [0079] high compression stockings generate3.3 to 4.7 kPa (25 to 35 mmHg) or higher.