Patent Application
20190000678
The present invention relates to compression stockings, and in particular to compression stockings formed from more than one part.
The term “compression stocking”, or sometimes “elastic compression stocking” refers to a garment worn around the leg which is elastically stretched by the leg when put onto it and which thus applies compression (pressure) to the leg in use. Compression stockings are typically used for a therapeutic purpose. They are typically stiffer elastically than conventional dress socks or stockings, to create greater pressure on the limb. Compression stockings can be categorised according to the pressure they exert in use. In one categorisation system, Class 1 or light compression stockings generate 1.9 to 2.3 kPa (14 to 17 mmHg); Class 2 or medium compression stockings generate 2.4 to 3.2 kPa (18 to 24 mmHg) and Class 3 or high compression stockings generate 3.3 to 4.7 kPa (25 to 35 mmHg). Pressures of 6.7 kPa (50 mmHg) and above are used in some cases. The pressure generated depends upon the size of the stocking and the size of the leg, and compression stockings need to be suitably sized for the individual, but in quoting pressures here and elsewhere in this document it is to be assumed that the stocking is correctly sized for the user.
The term “leg” is used herein in the colloquial sense to refer to the entire lower limb. The term “lower leg” is used to refer to the region of the leg from the ankle to the knee.
Many people suffer from venous and lymphatic insufficiency. This primarily affects the legs and can lead to varicose eczema, lipodermatosclerosis and venous leg ulceration. When the venous system in the legs is compromised, the resulting gravitational effect leads to venous hypertension. Venous insufficiency is a common condition. It is exacerbated by obesity, and so is becoming increasingly problematic in view of increasing obesity levels in the UK and other developed countries. It is the leading cause of varicose eczema and of leg ulceration.
Graduated compression hosiery has been used for many years to overcome venous hypertension. Typically compression is greatest at the ankles and reduces progressively toward the knees and thighs. The effect is to promote return blood flow up the leg. By wearing graduated compression stockings on a regular basis, patients can reduce the risk of varicose eczema and leg ulceration. Some graduated compression stockings extend from the foot to a region below the knee, while some extend above the knee to the thigh region.
The greater the tension in the stocking the greater the improvement in venous return. However, stockings of greater tension are more difficult to get on and off. Many of the patients requiring compression stockings are elderly, suffer poor mobility and may have arthritic joints, which adds to the difficulty involved. Physical force is needed to draw the stocking up the leg whilst putting it on. During removal there is a tendency for the leg part of a compression stocking to bunch just above the ankle, and moving the bunched material past the ankle requires a degree of force which can be difficult for a user lacking manual strength to exert.
A particular problem is that users of compression stockings may suffer from skin lesions, especially ulcers. Dragging a stocking over an ulcer is potentially painful and injurious.
There are numerous known devices to help the patient to get compression stockings on, but often the patient struggles later in the day to remove the stockings. This can lead to panic and many patients abandon use of compression stockings as a result.
The problems associated with putting on and taking off compression stockings are a major barrier to their use.
EP1337211 (Gloria Maglieria Elastica S.R.L) discloses an elastic stocking which is said to be easier to put on and which is formed in two tubular parts. One of these (we will refer to it as the “foot part”) is shown to be in the form of an open-toed sock worn on the foot and extending mid-way up the calf. The other part (we will refer to it as the “leg part”) is shown as extending from the ankle to just below the knee, and in a long region of overlap between these parts the compressive force of each individual part is approximately halved, so that in the overlap region the “integrity” of the stocking is maintained. The document does not address the question of how the stocking is to be put onto the leg. However a product of this type is sold by Gloria Med S.p.A under the trade name UlcerKit. Instructions offered in relation to that product show it being put on by first putting on the leg part and then putting on the foot part, drawing that up to surround the leg part where they overlap. Other than the stocking being in two parts, no other aspect of their invention facilitates the donning or removal of the stocking.
Putting the compression stocking on is still subject to problems. Consider in particular the use of such a compression stocking on a leg affected by a venous ulcer. These are most often found at or just above the ankle. In this case putting on the two part stocking may involve dragging the entire leg part over the ulcer, which is highly undesirable. Another problem is that it may be difficult for the user to judge how far up the leg the leg part of the compression stocking needs to be positioned, in order for it to overlap to the desired extent with the foot part. This may necessitate adjustment of the position of the leg part after the foot part is put on, but that adds to the inconvenience of the operation and may be problematic for users with limited strength or manual dexterity.
There are other known approaches to the problem of how to facilitate putting on a compression stocking. Some involve the use of zips or other fasteners, but these can create discomfort and are potentially unsightly.
At least one commercially available product uses a relatively low compression inner stocking and a higher compression outer stocking, each of them being shaped to cover the foot and lower leg. This product provides higher compression used to promote healing of established ulcers, rather than being used for the treatment of venous insufficiency. The inner stocking in one commercially available product of this type contributes compression of 1.3 kPa (10 mmHg) and the outer stocking contributes 4 kPa (30 mmHg). The inner stocking is to be put on first and has a slippery outer surface to reduce friction. But both stockings remain in place in use, and this is not optimal from the point of view of comfort. The two layers are also bulky to wear and less cosmetically acceptable than a single layer stocking.
WO91/05498 discloses a more elaborate arrangement in which an inner socklet used to facilitate donning of a compression stocking is to be pulled out of an open toe of the stocking once it is in place. This system is only valid for use with open toe stockings. Many patients find that open toe stockings are uncomfortable. Also this system offers no easy facility for removing the stocking once on the leg.
So despite the widespread and long standing adoption of compression stockings and the long standing recognition of the problems explained above, a need remains for an improved compression stocking which is convenient to put on and to take off. Desirably it should, in terms of its cosmetic appearance and of the compression it provides, be broadly comparable to a conventional unitary compression stocking. It is also desirable that the compression stocking should be capable of economical manufacture.
According to a first aspect of the present invention there is 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 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.
Adapting the compression stocking to be put on in this manner is counterintuitive. It is highly desirable that there should be little or no slip of the overlap portions of the two parts relative to one another, since if the overlap portions are not positioned one within the other then the pressures they exert will not sum correctly to provide the desired graduated compression profile. From this point of view it may be regarded as desirable to provide high friction engagement between the two parts of the compression stocking, making it difficult to drag the second part over the first.
But the inventor has recognised that the present invention can be used to provide a compression stocking that is both easier to put on and take off, and highly capable of resisting slippage.
The invention provides various advantages. Where the compression stocking is used to treat a venous ulcer, for example, the first part can cover the region of the ankle in which the ulcer is found, and serves to cover and protect the ulcer as the second part is then drawn into position. The coefficient of friction between the second part and the first part may be lower than that between the second part and the foot/ankle itself, meaning that the force needed to draw the second part into position is reduced, which is highly desirable for users with limited strength. And there is no need for trial and error in positioning the second part upon the leg because when it is put on, the first part is already in position to serve as a guide in this respect.
In accordance with a second aspect of the present invention there is 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
and a second part of the compression stocking being tubular and comprising
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.
Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:—
Compression stocking 10 illustrated in
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.
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.
When the compression stocking 10 is correctly worn on the leg (
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.
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.
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.
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.
The compression stocking 10 is intended and adapted to be put on in the following manner.
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.
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.
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.
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.
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.
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.
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.
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.
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. Dorsiflexion—that is, turning the foot about the ankle joint in the direction indicated by arrow 38 in
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
The dimension 44 may be varied in other embodiments.
The depth of the overlap zone (arrow 46 in
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
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.
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.
The compression stocking 10 illustrated in
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.
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.
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.
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.
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.
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:—
| Number | Date | Country | Kind |
|---|---|---|---|
| 1600044.0 | Jan 2016 | GB | national |
| 1614561.7 | Aug 2016 | GB | national |
This application claims priority to International Application No. PCT/GB2016/053845 filed Dec. 7, 2016, which claims priority to GB 1600044.0, filed Jan. 2, 2016, and GB 1614561.7, filed Aug. 26, 2016, which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB16/53845 | 12/7/2016 | WO | 00 |
