The invention pertains to the field of orthotics. More particularly, the invention pertains to a foot positioning aid. The foot positioning aid may be used as a night time foot positioning aid, for use whilst a person is sleeping.

Gastrocnemius muscle tightness is the primary cause of many foot and ankle and other medical conditions. Several papers have illustrated an association of conditions such as plantar fasciopathy, Achilles tendinopathy, gait abnormality, knee pain and back pain with tightness of the gastrocnemius muscle. Research is currently active in identifying a link between night time foot positioning and Achilles tendinopathy. In individuals who sleep prone or on their side, the feet spend the duration of sleep in full equinus. This inevitably causes contracture of the gastrocnemius muscle over time.

The clinical manifestations of gastrocnemius tightness result from overload of the forefoot during weight-bearing due to an inability of the ankle to dorsiflex sufficiently. At the end of the stance phase, the heel lifts off the floor. In the presence of a tight gastrocnemius and/or soleus, this will occur earlier in the gait cycle resulting in increased transmission of load to the forefoot. The development of gastrocnemius contracture causes an alteration in a persons normal gait cycle. The average gait cycle should proceed through‘three rockers’. The first rocker phase of gait is the heel strike and roll forward over the convex heel. The second rocker phase of gait concerns the progressive dorsiflexion of the ankle, allowing the tibia and the centre of gravity to progress over the foot. The third rocker phase of gait is the roll forward over the metatarsal heads. The foot turns from a supple weight-bearing object to a rigid lever at this moment, due to the action of the plantar fascia and the tibialis posterior tendon moving the foot into supination, and heel into varus.

The gastrocnemius muscle originates above the knee and blends with the soleus muscle to become the Achilles tendon, which inserts below the ankle on the calcaneum. Tightness of this muscle results in the inability to progress through the second rocker phase of gait. This causes entry into the third rocker phase early in the gait cycle, resulting in undue tension in the plantar fascia, tibialis posterior and Achilles' tendon. Pathology ultimately arises in areas of the foot that are under excessive stress as a consequence of the gastrocnemius tightness, and muscle groups that act against this tightness tire easily. This can further affect the muscles around the knee, hamstrings and lower back.

Although night splints have been used with success in the treatment of conditions like plantar fasciopathy and Achilles tendonopathy, their use is cumbersome and poorly tolerated at night. The current night time splints on the market are plantar splints that control foot position by cupping the foot. These are not specifically designed to prevent gastrocnemius tightness; however they do help if worn. Posterior splints are poorly tolerated in prone and side sleepers as they cause the foot to be suspended from the splint with the toes digging into the bed. Most people will discard these splints within a few hours of wear, making them very impractical in the long term prevention of gastrocnemius tightness. The present invention aims to achieve and maintain a normal, at least partially dorsiflexed, position of the foot during sleep by providing a cushioning on the anterior aspect of the foot and to work as a long term preventer of gastrocnemius tightness.

From a first aspect the present invention provides a cushion for the anterior aspect of the foot to encourage the foot to be in dorsiflexion during sleep, comprising a foot-facing surface, a base for resting on a sleeping surface, and a spacer region intermediate the foot-facing surface and base, wherein the cushion is configured to hold the ankle and guide the foot into dorsiflexion when the anterior of the foot and ankle face the sleeping surface.

The present invention addresses problems which can arise when individuals sleep on their front, in a prone position, or in any other way which results in the anterior of the foot and ankle facing the sleeping surface. It allows the foot to be supported so that the extent of dorsiflexion is enhanced, and hence the extent of equinus is reduced, compared to the situation in which the cushion is absent. The cushion in effect raises the sleeping surface in the vicinity of the ankle so that the ankle is raised up thereby reducing or avoiding the weight of the leg or foot forcing the foot into the equinus position. With the cushion underneath the anterior aspect of the ankle, the foot is able to adopt a relaxed position in which it can hang from the ankle, thus keeping the gastrocnemius complex in a resting length and not shortened. Thus the device is a night time foot positioning orthotic applied to the anterior aspect of the ankle, which prevents equinus foot positioning when the lower leg is in the prone position. The product of the present invention has a spacing function: it results in spacing between the foot, specifically the ankle region of the foot, and a bed. This spacing allows or encourages the foot to be in dorsiflexion, i.e. not to be in full equinus, during sleep or rest. In contrast, some prior art devices work by having a portion which is attachable to the lower leg and another portion which is attachable to the foot, thereby keeping the lower leg and foot in a fixed position relative to each other. The spacing effect provided by the present invention, by location of the device at the front of the ankle, is conceptually different.

The cushion has a foot-facing surface. This surface, in use, faces the anterior (front) of the ankle.

The cushion has a base, i.e. a surface on the opposite side of the cushion to the foot facing surface, such that when the anterior of the ankle is facing the foot-facing surface of the cushion and is facing downwards, the base rests on the sleeping surface.

The cushion may be configured to hold the ankle and guide the foot by supporting it in a particular orientation without necessarily attaching the cushion to the foot: in such cases the cushion may be stationary on the bed and - although there is a bias for the foot to assume a particular position - the foot may nevertheless move relative to the cushion and therefore relative to the foot-facing surface thereof. Thus, the device caters for movement which may occur during sleep or rest whilst still facilitating dorsiflexion for significant and sufficient durations. Certain movements, e.g. partial rotation of the foot, can occur without the foot moving off the cushion.

Alternatively the cushion may be configured to be attachable to the foot so that it is substantially held in place relative to the foot. In such cases the foot-facing surface is typically held in place against the anterior of the ankle such that if and when the foot moves the cushion also moves with it.

Where the cushion is attached to the foot, a side, surface or portion thereof opposite the foot-facing side of the cushion acts as a base when the foot assumes a downward facing position.

When the cushion is not attachable to the foot, it typically has a base which rests on and optionally is attachable to the sleeping surface, e.g. bed or mattress. The cushion may remain substantially stationary relative to the sleeping surface by virtue of having a stable base, e.g. a flat base, with a sufficiently large surface area to rest and remain immobile. The cushion may optionally be held in place by a sheet, for example a fitted sheet, over the top of the sleeping surface and cushion. Optionally attachment means, e.g. straps, may be provided to hold the cushion in place.

The product of the present invention allows or encourages the foot to be in dorsiflexion when in use. By dorsiflexion is meant some extent of dorsiflexion, i.e. that the foot is not in full equinus. Full equinus occurs when the tibial shank and the dorsum are in the same plane. Optionally the extent of dorsiflexion may be greater than or equal to 10 degrees from full equinus, or greater than or equal to 20 degrees from full equinus, or greater than or equal to 30 degrees from full equinus, or between about 20 degrees and 100 degrees from full equinus, or between about 20 degrees and 90 degrees from full equinus, or between about 20 degrees and 60 degrees from full equinus, for example.

It is not necessary for the dorsiflexion, or a particular extent of dorsiflexion, to occur for the entirety of the period in which an individual is in bed or sleeping. The present invention brings significant benefits by reducing the amount of time a foot spends in equinus or by increasing the extent of dorsiflexion, compared to the situation which would occur in the absence of the product. For example, the present invention may result in less than 50% of the time asleep, or less than 30% of the time asleep, or less than 20% of the time asleep, or less than 10% of the time asleep, being spent in positions of full equinus or significant equinus (e.g. less than 20 degrees dorsiflexion from full equinus).

The term“cushion” denotes a support, e.g. a soft support, on which the foot may rest. The support may yield to pressure and/ or be resilient. It may be made from any suitable material which is sufficiently comfortable for use. It may have properties suitable for use in bed, e.g. may be breathable or washable or have a removable washable cover.

The support may be formed, or comprise, for example, any suitable material e.g. rubber, silicone, elastomer, foam, fluoroelastomer, urethane, polyurethane, natural fiber, synthetic fiber, gel, water, natural latex, synthetic latex, polymer, thermoplastic elastomer or any other suitable material or combination of materials. The support may be used when an individual is lying in a horizontal or generally horizontal position, e.g. when sleeping or resting or unwell in bed. Several prior art documents disclose other types of apparatus for maintaining a foot in a dorsiflexed position. These generally include frames, splints or other components, or apparatus which envelop or constrain the foot to a large extent. The device of the present invention may seem to hold the foot less rigidly, and may seem to exert less control over the position of the foot, than known devices, but surprisingly the device of the present invention is highly effective in treating gastrocnemius muscle tightness and related foot and ankle conditions and thereby consequent conditions. Without wishing to be bound by theory, this may be because patient compliance is enhanced due to the comfortable nature of the device of the present invention and the likelihood that individuals will use the device regularly and for longer periods of time. It is also possible that patient compliance may be enhanced because individuals do not like using frames, splints or other bulky or rigid devices on their body when sharing a bed with another person.

Apparatus known in the prior art are generally used for short term periods (e.g. up to a few weeks) for the treatment of foot and ankle problems. Their poor comfort does not allow these apparatus to be used long term. The device of the present invention is comfortable and allows long term use. Furthermore, the present invention is useful not only to treat but also to prevent of foot and ankle problems. In contrast the prior art apparatus are not disclosed as being for, and generally would not be suitable for, preventative purposes. The prior art apparatus are not convenient for allowing the user to sleep in varying positions, because they are bulky and uncomfortable and move connected to the foot, thus disturbing sleep. In contrast the present invention provides a cushion which is either stationary relative to the bed or is maintained in position on the foot but which is comfortable and less bulky than prior art devices, allowing free movement during sleep in varying positions. Prior art devices often surround parts of the foot and leg whereas the device of the present invention works by spacing the front of the ankle from the bed rather than having any support or constraint in other areas.

Unlike some other orthotic devices, the device of the present invention does not require rigid components to be present on the base of the foot (e.g. a foot bed or foot plate) or on the posterior of the lower leg (e.g. a frame at the back of the lower leg), or a frame or splint to maintain the extent of dorsiflexion.

In contrast to known frames and splints, the present invention does not rigidly maintain the position of the foot relative to the lower leg, i.e. does not maintain a particular dorsiflexion angle at the ankle joint, solely by application of the device. Rather, the device when in use with a foot in a prone position encourages dorsiflexion and avoids equinus.

In contrast to some other known frames and splints, the present invention does not force the foot into an unnatural position. The device can allow the foot to be in a normal resting posture.

In order to provide a suitable rest for the anterior surface of the ankle, and to encourage a natural unconstrained position for the foot, the cushion may be of certain sizes appropriate for particular human dimensions. The device can conveniently be provided in certain standard sizes, e.g. small (wherein the distance from the foot-facing surface to the base, i.e. the size of the spacer region, is between 2.5 and 7.5 cm, e.g. between 3 and 7 cm, e.g. between 4 and 6 cm, e.g. about 5 cm), medium (wherein the distance from the foot-facing surface to the base, i.e. the size of the spacer region, is between 7.5 and 12.5 cm, e.g. between 8 and 12 cm, e.g. between 9 and 1 1 cm, e.g. about 10 cm), and large (wherein the distance from the foot-facing surface to the base, i.e. the size of the spacer region, is between 12.5 and 17.5 cm, e.g. between 13 and 17 cm, e.g. between 14 and 16 cm, e.g. about 15 cm). In some cases the size could be smaller or greater, for example between 2 cm and 20 cm. Thus, in general, the distance from the foot-facing surface to the base, i.e. the size of the spacer region, can optionally be between 2 and 20 cm, e.g. between 2.5 and 17.5 cm, e.g. between 3 and 17 cm, e.g. between 4 and 16 cm. The distance from the foot-facing surface to the base, i.e. the size of the spacer region, can also be understood as the height of the cushion, at the point where the foot is intended to rest.

Where the device is configured to rest on the bed, rather than move with the foot, the width of the base of the cushion (in the direction generally parallel to the leg, when in use) may optionally be about the same as the height of the cushion at the point where the foot is intended to rest, or may optionally be wider, e.g. up to 100% wider than it is high, e.g. between 10 and 50% wider than it is high, e.g. between 15 and 25% wider than it is high, e.g. about 20% wider than it is high. This facilitates stability. Thus, for example, the width at the base may be between about 5 and about 20 cm.

The cushion may shaped to be of generally elongate form such that in use the longer dimension of the cushion is approximately perpendicular to the direction of the leg. In this way the cushion can hold the ankle by supporting it in such a way as to allow the foot to hang from the ankle. Thus a substantially elongate perpendicular cushion guides the foot into dorsiflexion. The shape of the cushion may optionally be generally arcuate, arched, semicylindrical or a half roll or may have approximately rectangular or square cross-section or approximately frustoconical cross-section. The height of the cushion along the longitudinal direction may be substantially constant over at least a portion, or substantially all, or all, of the longitudinal direction. Alternatively, there may be one or more trough or depression within which, in use, the anterior of the ankle and foot can reside.

Regarding elongate cushions of the type configured to rest on the bed rather than being attached to the foot, particular lengths are convenient and useful. In the direction generally perpendicular to the leg, when in use, the cushion may extend across a significant portion of the width of a single bed or all of said width, or a significant portion of half the width of a shared bed (e.g. double, queen, or king-size bed) or all of said half-width. In this way the cushion occupies significant space in the area where it is required and where it can facilitate the correct positioning of the foot, without affecting another person in a shared bed. Often a user will lie with the foot which requires treatment in the prone position hanging over the cushion and the other foot will assume a position which is more on its side and higher up the bed, consistent with the leg of the latter foot being more bent. It is also possible for the device to be used to treat both feet simultaneously, though this may be less common because in general patients present with problems in one foot associated with having slept in a position which has caused problems in that foot. Optionally, suitable lengths of the elongate cushion can be within the range of 30 to 1 10 cm, or 40 to 100 cm, or 50 to 90 cm, or 60 to 90 cm, or 70 to 80 cm, for example.

In some embodiments a single cushion may be designed to support both ankles. The cushion may comprise two troughs, grooves or depressions, one for each ankle.

For example the cushion may have three peaks separated by two troughs. Thus the cushion may have an elongate form comprising two troughs which are substantially or approximately perpendicular to the longitudinal axis of the cushion. The troughs are channels or depressions on which the ankle may rest, and which hold or cup the ankle in the correct position.

The skilled person will note that the troughs need not be exactly perpendicular but may cross the longitudinal axis at an angle which does not need to be 90 degrees but may be some other slanting or oblique angle relative to the longitudinal axis e.g. at an angle of 70 degrees to 110 degrees relative to the longitudinal axis, or at an angle of 80 to 100 degrees relative to the longitudinal axis, or at an angle of 85 to 95 degrees relative to the longitudinal axis.

The base (bed-facing surface) of the cushion may be flat, to ensure stability on a bed, and to help avoid the cushion slipping or moving on the bed and reduce or remove the need to attach the cushion to the bed. This differs from simply using a conventional cushion which has convex surfaces. All of the base of the cushion may be flat. Alternatively, substantially all of, or most of, the base of the cushion may be flat; for example at least 70% or at least 80% or at least 90% or at least 95% of the footprint of the cushion may be flat to the extent that it is in contact with the bed when placed on the bed. (By“footprint” is meant the lateral extent of the cushion when projected vertically downwards to the bed surface. Thus a cube with side length of 1 m would have a footprint of 1 square metre, all of which is in contact with the bed so that 100% of the base is flat; whereas a sphere with a radius of 1m would have a footprint of 3.14 square metres of which only a point is in contact with the bed so that 0% of the base is flat.).

The base may be rectangular or substantially rectangular, for example may take the form of a chamfered or rounded rectangle.

The dimensions disclosed herein in relation to the lengths and widths of the elongate cushion may apply to the lengths and widths at the base.

For example, the length at the base (i.e. of the rectangle if the base is of rectangular shape) may be within the range of 30 to 110 cm, or 40 to 100 cm, or 50 to 90 cm, or 60 to 90 cm, or 70 to 80 cm, for example. Particularly suitable lengths may be those which are suitable for use in single beds or half of shared beds. Possible lengths include 30 to 110 cm or 50 to 1 10 cm or 50 to 100cm.

For example, the width at the base (i.e. of the rectangle if the base is of rectangular shape) may be within the range of 5 to 40 cm, or 5 to 30 cm, or 5 to 20 cm, or 10 to 30 cm, or 10 to 20 cm, or 12 to 17 cm, for example.

The front and back of the cushion (i.e. the surfaces which in use face the head of the bed and the foot of the bed respectively) may comprise flat wall portions. Said flat wall portions may be vertical or substantially vertical, for example may slope inwards by for example an angle within the range of 5 to 20 degree, for example 5 to 15 degrees, for example 8 to 12 degrees, for example about 10 degrees. The angled wall portions result in the cushion being broadest at its base thereby contributing to stability.

The top of the cushion may be generally rounded, domed or arcuate.

The cross-sectional shape of the cushion may have a rounded or domed upper surface. This may apply to the cross-sectional shape at the location of the troughs as well as the cross sectional shape at the location of the peaks.

The cross-sectional shape of the cushion may be a trapezium capped by a dome shaped or rounded structure. This may apply to the cushion in the region of the troughs and also in the region of the peaks: these may differ in that the height of the trapezium portion is greater in the region of the peaks compared to the troughs.

Thus the cushion may take the form of a substantially prismatic structure with a generally rounded convex top, out of which two approximately perpendicular troughs have been cut or into which two approximately perpendicular troughs have been formed.

The sides of the cushion (i.e. the surfaces which face the sides of the bed) may comprise flat wall portions. Said walls may be vertical or substantially vertical, for example may slope inwards by for example an angle within the range of 5 to 20 degree, for example 5 to 15 degrees, for example 8 to 12 degrees, for example about 10 degrees. The angled wall portions result in the cushion being broadest at its base thereby contributing to stability. The height of the cushion at the troughs, i.e. at the point where the foot is intended to rest, i.e. the size of the spacer region, may be as discussed herein, for example between 2 and 20 cm, or between 7 and 20 cm, or other ranges disclosed herein.

The three peaks may be sufficiently higher than the two troughs they contain (or, looked at a different way, the two troughs may be sufficiently deep) by an amount which, when in use, maintains foot positioning to a reasonable extent. For example, the difference in height between the top of the peaks and the base of the troughs may be within the range of 2 cm to 7 cm, or 2 cm to 5 cm, or 2.5 cm to 4.5 cm, or 2.5 cm to 3.5 cm, or about 3 cm.

The two troughs may be spaced apart from each other (with an intervening peak) by an amount which is suitable for and comfortable for typical human dimensions. For example, the centres, or lowest points, of each trough may be between 20 and 45 cm apart, or between 25 and 40 cm apart, or between 30 and 35 cm apart. This allows an individual to use the device for both feet, though that is not essential: an individual may use the device for only one foot even though there may be two troughs. Suitably the shape of the device is effected by an integrally formed cushion, i.e. a single cushion made of a single piece. Thus the shape of the device may be effected by forming a single cushion rather than by combining multiple cushions or components and fastening them together. The single cushion may be manufactured by forming two troughs in (e.g. cutting two troughs out of) an elongate cushion, and optionally by forming other shapes on (e.g. rounding by cutting away edges from) the elongate cushion. Alternatively the single cushion may be manufactured as a single entity by a forming process, for example injection moulding or 3D printing. Thus a single, unitary cushion may be manufactured by one of various techniques. An integrally formed single cushion is advantageous compared to a device prepared from several components fastened together. It can be prepared conveniently and cost- effectively and manufactured at large scale easily. It has structural strength and durability. It allows joins, boundaries or fastening points, which can lead to weakness, lack of durability, or other undesirable properties, to be avoided. Joints may also have the unwanted consequences of prominences that can lead to skin pressure areas on the user. The integrally formed nature can also allow for homogeneity, or, if desired, heterogeneity, of material properties to be tailored.

Although the shape of the cushion may be effected by an integrally formed single cushion, a separate cover for the cushion may be used. The term“integrally formed” relates to the shape and functional form of the cushion.

The cushion may be such that, in use, the extent of dorsiflexion of the foot is greater than 10 degrees of foot equinus.

Alternatively the cushion may be of a type which is configured to be attached to the foot. Such cushions not only provide support on the anterior surface, but also are maintained in place relative to the foot or ankle if the foot moves. For example the cushion may be strapped to the foot by attachment means (e.g. a strap) extending around the foot and/or attachment means (e.g. a strap) extending around the lower leg and or attachment means (e.g. a strap or a cradle) extending around the heel. It should be noted that unlike in some prior art devices the means of attachment in relation to the device of the present invention do not need to rigidly hold the foot fixed relative to the lower leg.

The cushion may be shaped so as to have side protrusions that extend posteriorly to at least partially envelop the ankle. This can ensure that the cushion is positioned correctly relative to the foot and ankle, and can also have a stabilising and/or attaching effect. The side protrusions may be resilient in the transverse direction such that they help to hold the cushion onto the foot by friction and/or transverse pressure (e.g. where the side protrusions comprise resilient material e.g. resilient foam) even where no further attachment means are used. Alternatively the side protrusions may be used in combination with further component(s) e.g. strap(s) to hold the cushion on the foot.

As noted above the cushion may be adapted to be positioned on a bed so that in use the user may rest the anterior aspect of the ankle on said cushion. Optionally means may be provided to attach the cushion to the bed or sleeping surface at an appropriate position. This may include straps or adhesive surface on the inferior aspect of the cushion attaching to the bed. In some forms however the cushion simply stays in position by resting on the bed or mattress, particularly if a sheet is positioned over the top. The sheet can be tucked in, in a conventional way, to secure the sheet, thereby trapping the cushion between sheet and mattress. A fitted sheet, i.e. one sized to fit the mattress or bed, can be used in a conventional way and can trap the cushion between sheet and bed.

The cushion may be adapted to be positioned over the corner of a mattress to provide a raised portion on which a user’s leg and/or ankle can rest. The cushion may therefore comprise an approximately right-angled cut-out portion on the part which in use is intended to be placed over the corner of a bed or mattress or sleeping surface. Attachment means, e.g. clips, straps or adhesive, may be provided on the cushion (or attachable to the cushion) to attach such cushion to the corner of a mattress.

From further aspects the present invention provides methods of treating or preventing a foot condition, for example gastrocnemius muscle tightness, or a condition related to the same, for example plantar fasciopathy or Achilles tendinopathy, comprising the use of a cushion or support as described above.

From further aspects the present invention provides a cushion or support as described above for use in therapy, for example for use in methods of treating a foot condition, for example gastrocnemius muscle tightness, or a condition related to the same, for example plantar fasciopathy, Achilles tendinopathy, forefoot overload, spring ligament pathology, posterior tibialis tendon pathology, metatarsalgia, forefoot arthritis, Morton neuroma, knee pain, or back pain.

A treatment regime may comprise using the cushion as a night time foot positioning aid for a period of several weeks or months, for example between 1 and 5 months, for example between 2 and 4 months, for example approximately 3 months.

From a further aspect the present invention provides a kit of parts comprising a bed, mattress or other sleeping surface, and a cushion as described above. The cushion may be suitably positioned on the bed, mattress or other sleeping surface, and/or optionally attached or attachable thereto.

From a further aspect the present invention provides a method of configuring a bed, mattress or other sleeping surface comprising providing a cushion as described above on said bed, mattress or sleeping surface. The invention is applicable to beds, mattresses or other sleeping surfaces and whilst reference has been made to sleep herein, it should also be noted that the present invention is useful in other scenarios where an individual is lying down or resting, e.g. where they are in a hospital bed or other healthcare setting and are undergoing treatment or recuperation. The medical care of some patients may include positioning them in a prone position on a bed, and the present invention can prevent or avoid exacerbating foot problems in such patients, as well as improve comfort. Such patients can include, for example, some patients with certain respiratory conditions including acute respiratory distress syndrome (ARDS). The respiratory conditions may arise in patients who have COVID-19 or other viral infection or for other reasons.

Variations of the shape of the cushion are possible, e.g. the cushion may have one or more foot-guiding feature(s) e.g. lateral elevations to allow the foot to rotate comfortably without moving off the cushion in different sleep positions. The foot can rest in or be biased towards stable equilibrium by use of such feature(s).

The present invention has been found to be particularly useful to treat, or to prevent problems arising in, a cohort of patients who are aged in their thirties, forties and fifties, for example aged between 35 and 55. Without wishing to be bound by theory, this may be for the following reasons. In general individuals who are children or young adults move frequently and therefore do not spend prolonged periods of time sleeping with their feet in full equinus, and in general individuals who are elderly do not sleep on their front as much as middle-aged individuals. In comparison, it is more common for 35 to 55 - year olds to experience the range of sleeping habits and also lifestyle patterns which may result in issues addressed by the present invention.

Surprisingly significant benefit can be brought about by using a cushion in accordance with the present invention, in the 35 - 55 age group but also in other age groups, in part due to the ease of use of the product, excellent patient compliance, and suitability for use in cases of prevention, or treatment at the first signs of problems, as well as treatment of developed conditions.

From further aspects the present invention provides cushions of the shapes and dimensions described herein. For example, from a further aspect the present invention provides an elongate cushion having a flat, substantially rectangular base which is between 50 and 90 cm long and between 10 and 20 cm wide, two depressions cut out of or formed on the top surface of the cushion, wherein said depressions take the form of troughs or channels which are substantially perpendicular to the longitudinal axis of said cushion, wherein the height of said cushion at said depressions is between 7 and 20 cm, and wherein said depressions are spaced apart, along the longitudinal axis of said cushion, by between 20 and 45 cm.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present invention can be understood in further detail and by way of non-limiting examples, the appended drawings are provided, in which:

Figure 1 shows in cross-section a problematic position which a foot may adopt in the absence of the cushion of the present invention;

Figure 2 shows in cross-section how a cushion according to one embodiment of the present invention may effect a more desirable positioning of the foot;

Figure 3 shows in perspective view the cushion of Figure 2 positioned on a bed;

Figure 4 and 5 show a cushion according to a further embodiment of the present invention in transverse cross-section and in plan view from above respectively, said cushion being designed to support both feet or to allow one foot to be located in one of two locations;

Figure 6 shows a cushion in use on a foot according to a further embodiment of the present invention from one side;

Figures 7 and 8 show a further views of the cushion of Figure 6 from the side on the foot and from above in isolation respectively;

Figure 9 shows a cushion in use according to a further embodiment of the present invention; and Figure 10 to 12 show a cushion, in perspective view, front view and side view respectively, according to an embodiment of the present invention which is similar to the embodiment shown in Figures 4 and 5.

It is to be noted that the appended drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention comprises other effective embodiments.

With reference to Figure 1 , in the absence of the device of the present invention, individuals who sleep prone or on their side on a bed, mattress or other sleeping surface (20) may adopt a position in which the lower leg and foot are in equinus as illustrated. In other words the angle between lower leg and foot increases to an extent that sleeping for the medium to long term in this position can cause contracture of the gastrocnemius muscle which can lead to various foot and medical conditions as described herein. The use of a foot cushion (10, 30, 40) as shown in any of Figures 2 to 9 can avoid or lessen this issue. The cushion (10, 30, 40) helps to support the weight of the leg and foot and provides a physical spacing effect between the anterior of the ankle and the bed (20) to encourage dorsiflexion of the foot and avoid the foot being forced into an equinus position.

As shown in Figure 2, the cushion (10) has a foot-facing surface (12), a base (14) for resting on a sleeping surface (20) and a spacer region (16) intermediate the foot-facing surface (12) and base (14).

The elongate form of one embodiment of the cushion (10), on a bed (20) is shown in Figure 3.

As shown in Figures 2 and 3 the cushion (10) may be a statically placed device on the resting surface (20), and foot positioning post application of this device is in dorsiflexion. It can be seen from Figure 3 that the cushion (10) may conveniently be positioned towards the foot-end of the bed (2), i.e. towards the opposite end to the head-end (which in Figure 3 is where pillows (22) are shown). In use, a sheet (not shown) may be positioned over the cushion (10) and over the bed (20) so that the sheet helps maintain the cushion (10) in the correct position. Alternatively the cushion (10) may be placed on top of the sheet, and/or other means may be used to hold the cushion in position. Figures 4 and 5 show a schematic representation of another embodiment of the device (10), illustrating three raised areas (18) and two troughs (12) which allows for foot turning during sleep. As shown in this representation, the troughs (12) may exhibit a reduced dimension not only in the height direction but also in the longitudinal direction, to encourage resting of the ankles in the appropriate locations. The raised areas (18) act as foot guiding features (18) to restrict lateral movement of the foot. The cushion (10) of this embodiment may also be positioned as shown in Figure 3. Some embodiments of the device not only cushion and support the anterior of the ankle and space it from the bed (20), but also have side portions (39) which extend along the sides of the ankle to partially or completely wrap around the sides of the ankle. Such a cushion (30) is shown, schematically, in Figures 6 to 8. The side portions (39) may grip onto the sides of the ankle. This may encapsulate the anterior aspect of the ankle, allowing movement with the individual on turning during sleep. As shown in these figures the device may adopt an ovoid shape that conforms to an individual’s ankle. The base (34), which is in on the opposite side of the cushion (30) to the foot-facing surface (32), and separated from the foot-facing surface (32) by a spacer region (36) rests on the sleeping surface (20) when the foot faces downwards, as shown in Figure 6.

Figure 9 illustrates a further embodiment where the foot positioning is accomplished using the end of the resting surface (20), and the device (40) acts to cushion this surface (20) to allow comfort during sleep. Clips, adhesive, straps (not shown) or other attachment means may be used to secure the device (40) to the corner of the mattress

(20), or the device may simply rest in position or be held by a sheet.

Figures 10 to 12 show a schematic representation of an embodiment of the device (10) similar to that shown in Figures 4 and 5 in that there are three raised areas (18) and two troughs (12). The cushion (10) of this embodiment is also typically positioned as shown in Figure 3. In this embodiment, the troughs (12) exhibit a reduced dimension in the height direction of the cushion but not in the longitudinal direction at the base of the cushion. It has been found that a reduced dimension in the height direction, such that there is a trough perpendicular to the longitudinal axis of the cushion, is sufficient to ensure that the leg is located correctly. Without wishing to be bound by theory, maintaining the full width of the cushion at its base may also be advantageous in maintaining the stability of the cushion and providing support to a greater length of the lower leg in the vicinity of the ankle.

The troughs of the cushion may be formed by cutting away portions from a larger structure. Alternatively, injection moulding or other technique may be used to form the shaped cushion.

EXPERIMENTAL RESULTS A trial was completed using 12 individuals who filled in a questionnaire following use of a foot pillow in accordance with the present invention for at least 1 week. The foot pillow was made from polyurethane memory foam.

The foot pillow tested was as illustrated in Figures 10 to 12, in two sizes.

The medium size was provided to individuals with feet of size 8 (UK) and below. The large size was provided to individuals with feet greater than size 8 (UK). The dimensions of the two sizes were as follows:

11 out of 12 had pain prior to the use of the orthotic. 10 out of 12 individuals self reported that they slept in either a side or prone position, which led to their foot taking an equinus position overnight. All individuals reporting an equinus foot position at night had pain. The location of the pain in each individuals foot was variable, however most located the area of pain to the plantar fascia or foot.

All 11 individuals who had reported pain prior to the use of the orthotic reported improvement in their pain. Using a validated tool of pain measurement, the visual analogue pain score (0-100 with 100 being worst pain and 0 being no pain), there was an average reduction in pain levels from 49.64 (95% confidence intervals 62.09, 37.19) to 21.18 (95% confidence intervals 28.82, 13.54) which is both a clinically and statistically significant difference. The following were comments made by the individuals; “the pillow has definitely improved the quality of the sleep I am experiencing and has helped with the pain when I get out of bed in the morning”,“The pillow is very comfortable and has helped with the pain in my feet” and“I have had amazing results from this. First week it took a lot of getting used to it. But pain is 80 per cent better.”