Tongue for footwear and footwear

Abstract

The present disclosure relates to a tongue for footwear and footwear, the tongue comprising: an outer substantially rigid layer comprising a first portion and a second portion, the layer being substantially saddle-shaped and generally conforming to a dorsal surface of a foot portion; and an inner filler layer providing contact with the dorsal surface of the foot portion, the inner filler layer having at least a first portion and a second portion; wherein the second portion is arranged to cover at least a portion of a deep peroneal nerve and / or a dorsal artery on the dorsal surface of the foot portion, and wherein the second portion is softer than the first portion.

Description

[0001] This application is a divisional application of PCT International Patent Application No. 202080011115.4, filed January 30, 2020, entitled “Liner and Tongue for Ski Boot Improving Ventilation and Pressure Distribution of the Foot,” the disclosure of which is incorporated by reference herein in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates to embodiments of a liner for a ski boot, a tongue for a ski boot liner, and variations of a tongue for footwear having a tongue. BACKGROUND

[0003] As recognized by most skiers, cold and sore feet can be an issue when wearing ski boots and skiing for long periods of time. Despite many known measures that can be taken into account, including ensuring that the ski boots fit well, wearing socks with a high warmth-to-weight ratio, ski boots actively heating, etc. However, the ski boots are tightened to provide proper support, which is also important for ski performance. However, tightening can increase the risk of blocking blood vessels in the foot, which in turn increases the risk of cold feet.

[0004] Many other types of footwear rely heavily on a tight fit between the shoe and the foot in order for the footwear to follow the movements of the foot in the best way, and thus react quickly when the foot moves. This is particularly important in footwear such as sports shoes, where the ability of the user of the footwear to move the foot faster and with more control over the movement makes the overall performance better.

[0005] The paradox with most types of shoes, particularly sports shoes, is that in order to achieve a good fit and good control of the shoe, the shoe needs to be laced or buckled in the middle of the foot, creating a tight seal between the forefoot and the hindfoot. This will create two different climate zones for the foot and a tight seal between them. In addition, the effect of the lacing or buckling is usually to exert a lot of pressure on the dorsal surface of the foot.

[0006] It is often the case that the user of the shoe wants to tighten or lace the shoe, which will then have a lower degree of flexibility and the shoe can follow the foot to a greater extent. At the same time, the use of footwear, particularly sports shoes, gives the user discomfort due to the high pressure exerted on the foot. In some cases, such as ski boots, it is common to heat-form the liner, for example at the first time the shoe is worn, to individually fit it to the user’s foot. This allows the footwear to better adapt to the user’s foot. The resulting pressure is expected to be more evenly distributed when using the footwear, but many users still feel significant discomfort, particularly when wearing the footwear for long periods of time.

[0007] Another common drawback of many types of footwear is the lack of sufficient ventilation. While summer sandals can be made of lightweight materials to enhance ventilation, footwear that needs to provide support to the foot, provide insulating material for warmth, or provide a rigid layer for strength (such as ski boots, hiking boots, or work boots), ventilation is often insufficient. Thus, perspiration from the foot is not removed at a sufficient rate.

[0008] Therefore, there is a significant need for comfortable footwear that maintains the normal temperature of the user's foot while providing good control and support. SUMMARY

[0009] The present inventor has realized that the user does not have to choose between comfort of the foot and control of the footwear. Typically, the part of the footwear that contacts the dorsal surface of the foot has substantially the same softness. In contrast, the present inventor has found that there is a great benefit in increasing control and comfort of the foot by using parts (e.g., layers) that have different softness.

[0010] For example, by arranging a softer part of the footwear (e.g., a softer part of the insole of the footwear) so that it contacts the central part of the dorsal surface of the foot (preferably near important blood vessels, such as the dorsalis pedis artery and / or veins, near the skin), pressure on these blood vessels can be reduced. Thus, normal blood flow to the foot can be maintained, both providing oxygen for normal function of the foot and maintaining thermoregulation. In addition, the deep peroneal nerve is located near the dorsal surface of the foot, and reducing pressure on this nerve can result in reduced nerve pain.

[0011] In addition, the softer layer can be arranged so that the user has more control of the footwear. By arranging the softer layer so that it contacts the center of the dorsal surface of the foot (e.g., along the anterior-posterior axis of the center of the foot), when the footwear is used, the force acting on the foot is along the anterior-posterior axis toward the center of the foot. Thus, movement of the foot in the coronal plane can be more effectively inhibited than with ordinary footwear that does not have a softer layer arranged in this way. Ordinary footwear typically has a resultant force acting on the foot, i.e., a force that is downward. Thus, to limit movement of the foot in the coronal plane, a large force is needed. A footwear that includes a softer layer arranged to contact the center of the foot along the anterior-posterior axis limits the foot in the coronal plane without the need for a large force acting on the foot.

[0012] In addition, the softer layer can be configured to increase airflow, such as by being provided in a material with high breathability or being provided as a cavity. By being provided in a material with high breathability or being provided as a cavity, the softer layer further supports the normal temperature of the user's foot. Warm and moist air that is typically trapped in the toe area of conventional footwear can be removed through the softer layer.

[0013] The softer layer can be configured to form an air channel between the toe area of the footwear and the exterior of the footwear. For example, the softer layer can be provided as an air cavity extending along the tongue of the footwear for forming an air channel between the exterior of the footwear and the instep / toe area. The footwear can further be provided with one or more holes through other layers of the footwear to improve ventilation.

[0014] The addition of a softer layer in the footwear, such as in the tongue, can have a significant impact on the structural rigidity of the footwear / tongue. In order to maintain the structural rigidity (e.g. to maintain the shape of the footwear under stress), a support layer can be provided at least partially overlapping the softer layer.

[0015] Accordingly, the present disclosure relates to a liner for a ski boot, the liner comprising a tongue comprising:

[0016] a. an outer substantially rigid layer, the layer being substantially saddle-shaped and substantially conforming to an instep surface;

[0017] b. an inner filler layer is provided in contact with the instep surface, the inner filler layer having at least a first portion and a second portion, wherein the second portion is arranged to cover at least a portion of a dorsalis pedis artery on the instep surface, wherein the second portion is a cavity or a material arranged to be softer than a material of the first portion; and

[0018] c. a support layer arranged outside the outer substantially rigid layer, the support layer at least partially overlapping the second portion of the inner filler layer.

[0019] The dorsalis pedis artery is a blood vessel that carries oxygenated blood to the instep surface and the toes. It is a continuation of the anterior tibial artery, beginning at the ankle joint and ending at the proximal end of the interosseous space of the metatarsal bones. From here, it divides into the dorsal metatarsal artery and the deep plantar artery.

[0020] When pressure is applied to the instep surface, in particular to the dorsalis pedis artery, the blood flow to the foot can be reduced. When there is a lot of pressure on the instep surface, in particular on the dorsalis pedis artery, the blood supply to the foot through the dorsalis pedis artery can be greatly impeded. The reduction in blood flow to the foot can cause significant discomfort to the user, which can increase over time.

[0021] In a preferred embodiment of the present disclosure, the tongue of the footwear is configured to be in contact with the instep surface such that the deformation and compression of the dorsalis pedis artery is minimized while maintaining good stability of the foot. For example, the basis for maintaining full functional blood flow at the instep surface is to reduce the pressure exerted on at least a portion of the dorsalis pedis artery.

[0022] In one preferred embodiment of the disclosure, the second portion at least partially additionally covers the deep peroneal nerve. This nerve is important for the neurological function of the foot. Exerting pressure on this nerve, particularly in combination with a reduction in blood supply, can cause discomfort and pain to the wearer of the footwear. By reducing the pressure on this part of the dorsal surface of the foot, the discomfort associated with the pressure exerted on the nerve and the restriction of blood flow to the nerve can be reduced, thereby reducing the discomfort to the wearer.

[0023] The second portion, which is softer than the first portion, exerts less pressure on the contacted dorsal surface of the foot than the first portion exerts on the contacted area. This is due to the support force between the foot and the insole being substantially attributed to the first portion. By configuring the second portion to at least partially contact the dorsalis pedis artery and / or the deep peroneal nerve, the pressure exerted on these areas can be greatly reduced, thereby increasing the comfort of the wearer.

[0024] Having a second portion that is softer can increase the likelihood of the tongue collapsing due to the immense external pressure in a ski boot, or at least deforming over time. Therefore, in one embodiment of the disclosure, a support layer is provided lateral to the generally rigid layer, which provides structural support to the overall tongue structure of the footwear. This can include a flexural rigidity and low elasticity, thereby allowing the overall shape of the tongue to be maintained, even if the tongue is composed of a second portion that is higher in softness that would not contribute to the rigidity of the tongue. The support layer can be positioned such that it at least partially overlaps the second portion. The support layer can be symmetrical or asymmetrical in shape, and can be small in area, but still provide relatively large structural support. This can include the use of an elongate support structure that spans the area of the second portion. Furthermore, the support layer can include a single structure, or multiple structures, on each tongue.

[0025] In one embodiment of the disclosure, the second portion is configured such that lower pressure is applied to the dorsal surface of the foot along the anterior-posterior axis of the dorsal surface of the foot. The pressure distribution of this arrangement can be such that pressure applied to the foot along the anterior-posterior axis is increased. This can result in better planar stability of the foot, with reduced lateral movement of the foot. For footwear like ski boots, this is highly desirable, as ski movements are largely lateral.

[0026] The disclosure further relates to a tongue for footwear, the tongue comprising:

[0027] a. an outer, generally rigid layer, the layer being substantially saddle-shaped and generally conforming to the dorsal surface of the foot;

[0028] b. an inner filler layer for contact with the instep surface, the inner filler layer having at least a first portion and a second portion, wherein the second portion is arranged to cover at least a portion of the dorsalis pedis artery on the instep surface, and wherein the second portion is softer than the first portion; and

[0029] c. a support layer arranged outside the outer substantially rigid layer, the support layer at least partly overlapping the second portion of the inner filler layer.

[0030] The tongue can be any of the embodiments of tongues described in relation to the insole of a ski boot, and the tongue can be used for other purposes than ski boots, for example sports shoes where stability and tightness are of high importance.

[0031] The present disclosure further relates to an insole for a ski boot, the insole comprising a tongue, the tongue comprising:

[0032] a. an outer substantially rigid layer, the layer being substantially saddle-shaped and substantially conforming to the instep surface;

[0033] b. an inner filler layer for contact with the instep surface, the inner filler layer having at least a first portion and a second portion,

[0034] wherein the second portion is arranged to cover at least a portion of the dorsalis pedis artery on the instep surface, and wherein the second portion is softer than the first portion,

[0035] and wherein the outer substantially rigid layer has a thickness of at least 3 mm, more preferably 4 mm, even more preferably 5 mm, most preferably 10 mm over the area covering the second portion. The relatively thick outer substantially rigid layer of the tongue can compensate for the weakness of the second portion. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 An insole for a ski boot for receiving a foot according to one embodiment of the present disclosure is shown.

[0037] Figure 2 A cross section along a plane perpendicular to the front-to-back axis of a tongue of an insole according to the prior art is shown.

[0038] Figure 3 A tongue of an insole having a first portion and a second portion (5) and an outer substantially rigid layer (3) and a support layer (6) according to one embodiment of the present disclosure is shown.

[0039] Figure 4 A cross section along a plane parallel to the front-to-back axis of a tongue of a ski boot according to one embodiment of the present disclosure is shown.

[0040] Figure 5 A cross-section of a tongue of a liner according to one embodiment of the present disclosure is shown, along a plane perpendicular to the front-rear axis of the tongue of a ski boot, the tongue having a support structure (6) covering at least partially the second portion (5).

[0041] Figure 6 A cross-section of a tongue of a liner according to one embodiment of the present disclosure is shown, along a plane perpendicular to the front-rear axis of the tongue of a ski boot, wherein the substantially rigid layer comprises a first portion (8) and a second portion (7).

[0042] Figure 7 A cross-section of a tongue of a liner according to one embodiment of the present disclosure is shown, along a plane perpendicular to the front-rear axis of the tongue of a ski boot, wherein the second portion exerts a pressure on the dorsal surface of the foot significantly lower than the pressure exerted by the first portion.

[0043] Figure 8 A cross-section of a tongue of a liner according to one embodiment of the present disclosure is shown, along a plane perpendicular to the front-rear axis of the tongue of a ski boot, wherein the second portion exerts a pressure on the dorsal surface of the foot significantly lower than the pressure exerted by the first portion.

[0044] Figure 9 A cross-section of a tongue of a liner according to one embodiment of the present disclosure is shown, along a plane perpendicular to the front-rear axis of the tongue of a ski boot, how it deforms when the ski boot is tightened.

[0045] Figure 10 A cross-section of a tongue of a liner according to one embodiment of the present disclosure is shown, along a plane perpendicular to the front-rear axis of the tongue of a ski boot, how it deforms when the ski boot is tightened.

[0046] Figure 11 A ski boot with a liner according to one embodiment of the present disclosure is shown.

[0047] Figure 12 A cross-section of a tongue of a footwear is shown, along a plane perpendicular to the front-rear axis of the tongue, wherein the second portion is provided as a cavity.

[0048] Figure 13 A cross-section of a tongue of a footwear is shown, along a plane perpendicular to the front-rear axis of the tongue, wherein the second portion is provided as a cavity, and in addition a hole is provided in the substantially rigid layer.

[0049] Figure 14 A cross-section is shown, along a plane parallel to the front-rear plane of a foot in a footwear, the footwear comprising a second portion provided as a cavity for increased ventilation.

[0050] Figure 15A footwear is shown in which the second portion is provided in the form of a cavity which extends towards the exterior of the footwear for forming an air passage between the interior of the footwear and the exterior of the footwear when in use.

[0051] Figure 16 A footwear is shown in which the second portion is provided in the form of a cavity which extends towards a hole in the generally rigid layer of the exterior for ventilation. DETAILED DESCRIPTION

[0052] The present disclosure relates to a liner for a ski boot, the liner comprising a tongue comprising an outer generally rigid layer, the layer being generally saddle-shaped and generally conforming to the instep surface, and optionally also to a portion of the lower leg, such as the front of the lower leg. The rigid layer of the liner generally provides the overall shape of the tongue. This is a relatively rigid construction with relatively little flexibility in order to provide more efficient energy transfer between the skier and the ski boot (and further to the edges of the ski).

[0053] It is preferred that an inner fill be present between the foot and the generally rigid layer, and optionally a portion of the lower leg, such as the front of the lower leg. In addition, the inner fill can include a cushion in contact with the foot, such as a felt fabric. Thus, the first portion and / or the second portion can include a cushion in contact with the foot. The cushion can be configured to provide comfort and / or temperature control to the foot, while in general it does not provide any substantial fit and support to the foot. On the other hand, the inner fill is preferably made of a foamed material and provides insulation and cushioning, and to some extent it also provides support to the foot. In one preferred embodiment of the disclosure, the inner fill layer has at least a first portion and a second portion, wherein the second portion is softer than the first portion. The material used for the inner fill layer is most commonly a synthetic foam material. The difference in softness can be provided by using different materials within the inner fill layer or by foamed materials having different foaming properties, such as having different ratios of material to cavities. In addition, the thickness of the portions can be different, such that the first portion can be thicker than the second portion. The positioning and configuration of the portions should be such that they cover different portions of the foot, and optionally also the lower part of the leg. Preferably, the second portion is generally softer than the first portion and covers at least partially the dorsalis pedis artery on the dorsal surface of the foot. In one embodiment of the disclosure, the configuration of the first and second portions is such that the portion of the dorsal surface of the foot covered by the second portion is subjected to lower pressure than the portion of the dorsal surface of the foot covered by the first portion. Preferably, the reduced pressure exerted by the second portion is a result of its being softer than the first portion. However, the reduced pressure must also be considered in relation to the configuration of the first portion, since the first portion is positioned in such a way that it provides the main pressure to the foot and avoids compression of the second foot portion. In this embodiment of the disclosure, the first portion can be seen as a support structure, which due to its lower softness provides support to withstand the greater compression of the second portion. The two materials can have different relationships between applied stress and strain. As an example, the second portion can have a lower Young's modulus than the first portion, resulting in that if the two materials are compressed by an equal distance, which is true at the boundary between the two materials, the resulting pressure exerted by the second portion to the surface of the respective portion of the foot in contact with it is lower than the pressure with respect to the first portion. In this way, the pressure distribution within the cushion, including the portion in contact with the dorsal surface of the foot, can be controlled in order to provide optimized values for the different portions of the cushion, such as in relation to their respective functions and further in relation to the anatomy of the foot in contact.

[0054] In one preferred embodiment of the present disclosure, a support layer is arranged outside the outer substantially rigid layer, which support layer at least partially overlaps the second portion of the inner filler layer. The support layer can provide additional rigidity in order to maintain the shape of the tongue in situations such as repeated stress cycles and in situations of high load. The use of a second portion with increased softness relative to the first portion can reduce the stability of the shoe, in particular the tongue. The tongue of a ski boot can be one of the main components that transmit forces from the foot to the equipment. Therefore, its stability and rigidity are of critical importance to the performance of the user. The tongue of a common ski boot cannot incorporate a second portion with a softness higher than that of the first portion, because it is easy to collapse the padding, in addition to the fact that the efficiency of the energy transmission between the foot and the equipment is reduced. In order to prevent this, one preferred embodiment of the present disclosure incorporates a support layer outside the substantially rigid layer in order to maintain the overall shape of the tongue of the padding. The area of the second portion can have greater mechanical stress due to its softness. Therefore, it is necessary to incorporate an appropriate reinforcement in order to ensure that the structure does not deviate enough to interfere with the function of the tongue and to ensure that the tongue behaves as expected under different loads.

[0055] In one embodiment of the present disclosure, the second portion is configured to at least partially contact the dorsal surface of the foot, where the dorsalis pedis artery is proximate to the epidermis. The epidermis is the outermost of the layers that make up the skin. Therefore, the location of the dorsalis pedis artery proximate to the epidermis is the location where the artery is proximate to the periphery of the body. At this point, the artery is not protected by the rigid structures of the body, such as the skeleton, and the application of pressure causes the artery to deform significantly. The pressure associated with the deformation of the artery is related to the blood pressure, which acts to withstand the deformation and overcome any pressure exerted on it. Normal blood pressure is generally considered to be 120 mm Hg (equivalent to 0.16 bar or 10700 N / m 2 ) of systolic pressure and 80 mm Hg (approximately equivalent to 0.11 bar or 16000 N / m 2 ) of diastolic pressure. In order to fully withstand the pressure applied to the foot, it is necessary to exert a force on the dorsal surface of the foot that translates into a pressure on the dorsalis pedis artery greater than 0.16 bar. The configuration of the second portion with a pressure on the area of the dorsalis pedis artery that is significantly lower than this value will therefore act to maintain the function of the artery and the normal function of the foot.

[0056] In one preferred embodiment, the second portion exerts a pressure lower than the pressure exerted by the first portion on the dorsal surface of the foot. In addition to the fact that the pressure applied to the foot is less, the second portion can also provide climate control, comfort and fit. Therefore, the second portion preferably has considerable thermal insulation and elasticity, which can act to provide comfort, better control of the ski boot, in addition to being more efficient in the transmission of energy from the foot to the edge of the ski boot and ski.

[0057] In yet another embodiment of the present disclosure, the second portion is arranged such that the pressure exerted on the dorsal surface where the deep peroneal nerve is near the epidermis is less than the average pressure exerted by the first portion. Pressure exerted on the deep peroneal nerve can cause significant discomfort to the wearer of the ski boot. This discomfort can be directly related to the pressure on the nerve, which can be recorded as pain above a certain threshold pressure level. In addition, this discomfort can be related to numbness or "pins and needles" tingling or cramping in the foot. Pressure exerted on the nerve can further reduce the functionality of the foot, such as limiting the range of motion of the foot or toes, or reducing the force exerted by the muscles of the foot. The primary driver behind the discomfort associated with the foot and the nerve is due to the loss of sensory nerve function, and symptoms can be related to pressure directly exerted on the deep peroneal nerve, but can also be (or in addition to) related to reduced blood flow to the nerve. This can be related to pressure exerted on the dorsalis pedis artery, but can also be (or in addition to) due to pressure exerted on the small blood vessels surrounding the deep peroneal nerve.

[0058] In one embodiment of the present disclosure, a pad for a ski boot, the pad comprising a tongue, the tongue comprising an outer substantially rigid layer, the layer being generally saddle-shaped and generally conforming to the dorsal surface of the foot. The tongue further comprises an inner filler layer provided in contact with the dorsal surface of the foot, wherein the inner filler layer has at least a first portion and a second portion, wherein the second portion is softer than the first portion and arranged such that it at least partially covers the deep peroneal nerve and / or the dorsalis pedis artery on the dorsal surface of the foot. The outer substantially rigid layer has a first portion and a second portion, wherein the second portion has a thickness of at least 3 mm, more preferably 4 mm, even more preferably 5 mm, most preferably 10 mm, in the area covered by the second portion. Preferably, the thickness of the first portion of the substantially rigid layer is lower than the thickness of the second portion. The first and second portions of the rigid layer can be further positioned such that the first portion substantially covers the sides of the tongue along its anterior-posterior plane. The second portion of the rigid layer is primarily positioned in the center along the same anterior-posterior plane of the tongue. Thus, the thickness of the tongue of the pad of this embodiment of the present disclosure is variable, wherein the thickness along the general center of the anterior-posterior plane of the tongue is generally higher than the thickness on the sides.

[0059] Pads

[0060] The present disclosure relates to a liner of a ski boot, other terms for which include an inner boot and an inner ski boot of a ski boot, which is intended to be positioned inside the shell of a ski boot, which is usually provided with means for fastening the ski boot, such as buckles and straps. The inner boot is made to provide insulation, cushioning, comfort and support. The inner boot comprises several parts, which are usually stitched or glued together, forming the liner. The front upper part is open to allow the entry of the foot and can usually be closed by means of laces and / or Velcro. There is usually a tongue of the liner. The tongue comprises a substantially rigid layer, since this part is the one that transmits the forces generated by the skier to the shell of the ski boot and further to the ski. The flexibility between the skier and the tongue can cause a loss of force and / or reaction time. At the same time, in order for the tongue of the foot to adapt to the foot, a certain flexibility and softness is required, and it can also provide insulation and cushioning. Alternative designs of ski boots have been shown, but the inner ski boot comprises a tongue of substantially rigid material, which better transmits the energy from the foot and / or calf to the ski and to the edge of the ski. Therefore, this design of ski boot and its corresponding liner is generally known as the Cabrio design, which is the most common to date.

[0061] Dorsalis pedis artery

[0062] In a preferred embodiment of the present disclosure, the second portion at least partially covers the dorsalis pedis artery. The dorsalis pedis artery (arteria dorsalis pedis in Latin) is a blood vessel of the lower limb that carries oxygenated blood to the dorsal surface of the foot. It is located 1 / 3 of the way from the medial malleolus. It arises from the anterior aspect of the ankle joint, being a continuation of the anterior tibial artery. It terminates in the proximal intermetatarsal space, where it divides into two branches, the first dorsal metatarsal artery and the deep plantar artery. The dorsalis pedis artery communicates with the blood supply of the sole of the foot through the deep plantar artery. The dorsalis pedis artery emerges from under the tendon of the extensor hallucis longus and rides on the parts of the tarsal, navicular, cuneiform and proximal metatarsal bones that are the general area of the dorsal surface of the foot, where the blood flow through the dorsalis pedis artery can be reduced by applying a relatively small amount of pressure, and can be severely obstructed under moderate to high pressure. The pulse of the dorsalis pedis artery can be easily palpated on the lateral side of the tendon of the extensor hallucis longus (or the medial side of the tendon of the extensor hallucis longus) on the dorsal surface of the foot, distal to the most prominent dorsal aspect of the navicular bone, which is a reliable landmark for palpation. Doctors often check this area when assessing whether a patient has peripheral vascular disease.

[0063] Deep peroneal nerve

[0064] In a preferred embodiment, the second portion, which at least partially overlies the deep peroneal nerve (nervus peroneus profundus in Latin), begins at the bifurcation of the common peroneal nerve between the fibula and the superior part of the peroneus longus muscle, passes medially deep to the longus muscle, to the anterior surface of the interosseous membrane, and above the middle of the leg comes into relationship with the anterior tibial artery; it then descends with the artery to the front of the ankle joint, where it divides into lateral and medial terminal branches. In the leg, the deep peroneal nerve provides muscular branches to the anterior compartment of the leg and articular branches to the ankle joint. After passing the bifurcation of the ankle joint, its lateral branch innervates the abductor pollicis brevis and abductor pollicis longus, while the medial branch continues to provide cutaneous innervation to the first and second interdigital webs. Similar to other major arteries and important nerves of the human body, the location of the deep peroneal nerve is closely related to the location of the dorsal artery of the foot.

[0065] Dorsalis pedis vein

[0066] The dorsal venous arch of the foot is a vein that lies parallel to the dorsal artery of the foot and is one of the veins that carry venous blood back from the forefoot.

[0067] 3-point pressure distribution

[0068] The insole of a ski boot comprises a tongue having a first portion and a second portion, wherein the second portion exerts a pressure on the foot which is generally lower than the pressure exerted by the first portion. By using the insole of a ski boot, an optimized pressure distribution on the dorsal surface of the foot can be created. In a preferred embodiment of the present disclosure, this pressure distribution results in an increased planar stability of the foot. By configuring the second portion to be in contact with the dorsal surface of the foot substantially parallel to an axis from the front of the foot to the back of the foot, substantially through the center of the surface. By positioning the second portion in this way in the center of the foot in the front-to-back direction, the pressure distribution on the foot is significantly altered. The cross-section of the tongue of the insole in the coronal plane of the foot can be considered a ring-shaped sector. Thus, the dorsal surface of the foot in contact with the inner filling along this ring-shaped sector will be subjected to normal forces perpendicular to the surface. These forces have a magnitude and a direction such that the direction of all normal forces of the ring-shaped sector points towards the origin of the ring-shaped sector. The ring-shaped sector can be defined by an angle a, wherein the ring-shaped sector is approximately in the range of -π / 2 rad (radians) to π / 2 rad, such that a = 0 is in the center of the ring-shaped sector. For a tongue of an insole of a ski boot consisting of an inner filling having a single softness, the magnitude of the normal forces acting on the dorsal surface of the foot will be significantly higher at the points of the tongue in contact with the foot close to a = 0 rad than at the points of the tongue in contact with the foot at higher angles of the ring-shaped sector, such as -π / 6 to π / 6 compared to the outer sectors -π / 2 to -π / 3 and π / 3 to π / 2. However, by using a tongue having multiple softnesses, the pressure distribution can be altered. By configuring the second portion to be in contact with the foot within the ring-shaped sector of -π / 6 to π / 6, while the first portion is in contact with the dorsal surface of the foot in the rest of the ring-shaped sector, such as π / 2 to -π / 6 and π / 6 to π / 2, a modified pressure distribution on the dorsal surface of the foot can be achieved, wherein a higher pressure can be exerted on the foot in the areas of the dorsal surface in contact with the first portion, while a lower pressure can be exerted on the foot in the areas of the foot in contact with the second portion. This redistribution of pressure can result in a planar stability of the foot in this way, wherein the larger pressure on the dorsal surface of the foot comes from the sides further away from a = 0 rad than close to a = 0 rad. This results in a three-point pressure system, wherein the sum of the normal force vectors from each half of the ring-shaped sector on the opposite sides of the ring-shaped sector can result in two substantially mirrored vectors, each pointing towards the origin of the ring-shaped sector. This provides a more stable foot fixation, as the normal forces reduce the movement of the foot in the coronal plane and the transverse plane.

[0069] In one preferred embodiment of the present disclosure, the support layer is configured to not cover the entire annular sector of the cross-section of the tongue of the liner. Preferably, the tongue is configured such that the annular sector is covered by the support layer between -5π / 12 and 5π / 12, more preferably between -π / 3 and π / 3, even more preferably between -π / 4 and π / 4, most preferably between -π / 6 and π / 6. By having a support layer that only covers a portion of its cross-section along the anterior-posterior axis, the tongue is better able to adapt to the shape of the footwear.

[0070] Material properties

[0071] The liner is a removable inner boot of a ski boot. It is usually made of foam, leather, textile and injection plastic components. It provides a cushion for the foot to protect it from the rigid plastic of the outer shell. The cushion of a racing boot is minimal, using a solid material such as cork, in order to allow the athlete to instantaneously "on / off" connect to the boot shell, and thus to the ski. At the other end of the spectrum, comfort / "athletic" level boots can have a deep cushion liner; they can thus provide additional comfort to the foot, but generally offer less circulation between the foot and the ski boot shell.

[0072] As discussed earlier, the tongue of the liner is generally the most important part to efficiently transmit forces from the foot to the shell of the ski boot and further to the ski edges. In order to have a faster reaction without losing energy, a more rigid tongue is preferred. However, the drawbacks of a more rigid tongue can include a decrease in comfort. The ability to adapt to the foot profile can decrease with the increase in rigidity of the tongue.

[0073] The material of the different parts of the liner, in particular the tongue of the liner, can be chosen to optimize its function. This can further depend on the type of shoe, whether it is a ski boot for racing or a shoe where more comfort is required. However, in general, the tongue of a ski boot generally comprises a substantially rigid layer, which shape substantially coincides with the dorsal surface of the foot. The substantially rigid layer is generally the main component that maintains the shape of the tongue and further efficiently transmits energy from the foot to the ski. Due to the rigidity of the substantially rigid layer, it is often desirable to have an internal padding to adapt to the shape of the foot and provide more comfort. The internal padding can additionally have a thin liner, such as a felt fabric, which replaces the internal padding in contact with the foot, serving to increase comfort and moisture absorption.

[0074] The tongue of the common liner currently available in the market is generally composed of a substantially rigid layer, which is substantially continuous in thickness of 2 mm. Common materials of this layer include acrylonitrile-butadiene-styrene (ABS) or low-density polyethylene (LDPE), with other materials less common for ski boots, but they can additionally or alternatively include other types of polymers such as nylon, polyethylene, ethylene-vinyl acetate (EVA), high-density polyethylene (HDPE), polystyrene (PS), polyolefins, or other polymers.

[0075] By having a portion, such as the second portion, of the internal filler of the tongue to be of a softer material, the structural rigidity of the tongue is reduced. Thus, the tongue can require additional reinforcement to prevent structural failure. When using a second portion of increased softness, the ability of the substantially rigid layer to resist deformation is also reduced. Different methods can be used to ensure the structural rigidity of the tongue of the liner, and these methods can be used simultaneously.

[0076] Having a support layer outside the substantially rigid layer can also be used to maintain the structural rigidity of the tongue when using a second portion of increased softness. The support layer can be configured to at least partially cover the second portion of the internal filler of the tongue. The support layer can be a metal composition or a single substance, such as a spring steel sheet, with a thickness of at least 0.5 mm. Alternatively, the support layer can include a polymer, such as Kevlar or fiberglass, or another synthetic material. It can also be a combination of materials selected so that the support layer has a significant degree of hardness compared to the generally rigid layer, particularly the internal filler layer. An alternative method to maintain the structural rigidity of the tongue is to increase the thickness of the substantially rigid layer. The thicker substantially rigid layer can be made of the same materials as the traditional one, but still with increased structural rigidity. Analysis using finite element analysis (FEA) indicates that increasing the substantially rigid layer to 5 mm is sufficient to prevent structural failure of the tongue during use for the relevant pressures acting on the tongue.

[0077] A third alternative method to maintain the shape of the tongue can be to have the substantially rigid layer composed of alternative materials with a higher degree of hardness. These materials can include metals and polymers, selected so that the substantially rigid layer provides a significant degree of hardness.

[0078] The first portion of the interior fill of the tongue can be made of ethylene vinyl acetate (EVA) and / or low density polyethylene (LDPE) and / or high density polyethylene (HDPE) or other ethylene materials such as expanded ethylene or composites thereof. The stiffness of these materials is largely influenced by the material to void ratio, which is determined when the foam is manufactured. The greater the void ratio in the foam, the softer the final material. Thus, the softness of the final foam material can be adjusted within a range. Accordingly, the second portion can include the same material as the first portion, but can differ in the performance of the foam, such as a lower material to void ratio. Additionally, the second portion can be less thick than the first portion, such that the first portion needs to be compressed before the area of the second portion contacts the dorsal surface of the foot.

[0079] Ethylene vinyl acetate (EVA) is a copolymer of ethylene and vinyl acetate. It is an extremely resilient material that can be sintered into a porous material that resembles rubber, but with excellent toughness. The porous elastomeric material is generally three times more flexible than low density polyethylene (LDPE), showing a tensile elongation of 750% and a peak melt temperature of 250°F (96°C). This flexible porous plastic material has good barrier properties, cold flexibility, stress crack resistance, hot melt adhesive waterproofing, and resistance to ultraviolet radiation. Porous EVA can have little or no odor and is generally competitive with rubber and vinyl products in many electrical applications.

[0080] Temperature Regulation

[0081] As previously mentioned, one important aspect of the present disclosure is to maintain the normal temperature of the foot while using the footwear. The temperature of the foot can deviate from the normal temperature due to the lack of blood supply to the foot, which then cannot support temperature regulation. Normally, the blood maintains the balanced temperature of the foot by providing blood with a normal body temperature while carrying away hotter and colder blood. In this way, the blood acts to balance the temperature in the body. When the blood flow is restricted, this process is reduced and the temperature variations in the body can increase.

[0082] One common drawback of footwear, such as those requiring good control, support or structural rigidity, such as sports shoes, ski boots or work shoes, is that a great pressure is exerted on the surface of the foot, such as the dorsal surface, when in use. A common drawback of the close fit and the great pressure exerted on the foot is that it causes a reduction in blood flow, thus reducing the temperature regulation capacity of the foot. The temperature regulation can be improved by providing a portion of the tongue of the footwear, such as a pad, or as a cavity, with a softer material. The softer material or cavity, such as the second portion of the inner filling, can be arranged so that it allows an increase in blood flow to the foot, such as normal blood flow. Furthermore, the softer material or cavity, such as the second portion of the inner filling, can be arranged to provide more ventilation to the foot, such as between the toe area of the footwear and the lateral side of the footwear.

[0083] Anatomical plane

[0084] The planes defined herein refer to anatomical planes, i.e. hypothetical planes used to describe the position of structures or the direction of movement. In human and animal anatomy, three main planes are used: the sagittal plane or median plane (longitudinal, forward) is a plane parallel to the sagittal suture. It divides the body into left and right; the coronal plane or frontal plane (vertical) divides the body into dorsal and ventral (back and front, or posterior and anterior) portions, which corresponds to a plane perpendicular to the anterior-posterior axis of the footwear / tongue, these terms being used interchangeably herein. The transverse plane or axial plane (transverse, horizontal) divides the body into cranial and caudal (head and tail) portions.

[0085] Detailed description of the drawings

[0086] The invention will be described in more detail below with reference to the accompanying drawings. The drawings are exemplary and are intended to show some of the features of the tongue of the insole of the ski boot or other footwear of the present disclosure, and should not be understood as limiting the invention of the present disclosure.

[0087] Figure 1 An insole (1) for a ski boot for receiving a foot according to one embodiment of the invention is shown. The insole has a tongue (2), wherein the tongue comprises a substantially rigid layer (3) and an inner filling having a first portion (4) and a second portion. The insole can be equipped with means for closing the insole, such as laces or Velcro straps. The insole comprises different materials, which are selected according to their specific use, for example, a more rigid material generally constitutes the outer layer of the insole, for providing structural stability, while the inner layer, closer to the foot, is generally softer, thus providing comfort to the foot.

[0088] Figure 2A tongue of a liner for ski boots according to the prior art is shown. The pressure exerted on the instep surface is generally substantially higher in the central part of the profile than in the peripheral part of the profile. This can cause discomfort for the user of the liner, since the pressure distribution is clearly uneven, in addition to possibly exerting a great pressure on the area of the instep surface, thus affecting the blood flow through the main blood vessels and the functioning of the main nerves.

[0089] Figure 3 A tongue of a liner having an inner filler layer with a first part and a second part (5) and a substantially rigid layer (3) and a support layer (6) is shown according to one embodiment of the present disclosure. By using a first part and a second part, where the second part is softer than the first part, the structural integrity of the tongue of the liner can be affected. The use of a support layer, where the support layer at least partially covers the second part, can act to maintain the overall shape of the tongue, even under the pressure associated with its use. The inner filler of the tongue or the entire tongue can be padded with a felt fabric to provide more comfort.

[0090] Figure 4 A profile along a plane parallel to the front-rear axis of the tongue of a ski boot is shown according to one embodiment of the present disclosure. The first part (4) is configured to be in contact with the instep surface, in addition to possibly being in contact with the lower part of the leg. It can be covered on the liner, such as a felt fabric. The role of the first part is to provide primary support between the foot and the substantially rigid layer (3). The second part (5) is configured so that it is softer than the first part, in addition to which it can also provide climate control, comfort and fit. The second part is positioned so that it at least partially covers the dorsalis pedis artery, for example in the area where the dorsalis pedis artery approaches the epidermis layer of the instep surface. Preferably, the second part is configured so that it exerts a pressure on the instep surface that is significantly lower than the general pressure exerted by the first part. Thus, the pressure exerted on the artery can be reduced and its normal functioning maintained, while maintaining the efficiency of the energy transfer and the reaction time of the ski boot, since this is largely related to the rigidity of the tongue of the liner of the ski boot.

[0091] Figure 5A cross section of a tongue of a liner according to an embodiment of the present disclosure is shown in a plane perpendicular to the front-back axis of the tongue of a ski boot, the tongue having a support structure (6) covering at least partially the second portion (5). The first and second portions of the inner filler are configured so that the second portion is in contact at least partially with the area of the dorsal artery of the dorsal surface of the foot close to the epidermis layer. The second portion is positioned in the annular sector (which is the cross section of the tongue) so that it is between two values, such as -π / 6 and π / 6 rad, while the first portion is configured to cover the rest of the tongue, such as -π / 2 to π / 6 and π / 6 to -π / 2 rad. In order to maintain the overall shape of the tongue while still allowing the second portion to have a significant softness, a support layer (6) composed of a rigid material (such as steel) is used, with a thickness of, for example, 0.5 mm.

[0092] Figure 6 A cross section of a tongue of a liner is shown in a plane perpendicular to the front-back axis of the tongue of a ski boot, wherein the substantially rigid layer comprises a first portion (8) and a second portion (7). The second portion of the substantially rigid layer has a thickness of 5 mm in the embodiment. The first central portion (8) of the outer substantially rigid layer (3) has a thickness of 4.2 mm in the area coinciding with the second portion (5), possibly thinner in the second portion (7).

[0093] Figure 7 A cross section of a tongue of a liner according to an embodiment of the present disclosure is shown in a plane perpendicular to the front-back axis of the tongue of a ski boot, wherein the second portion exerts a pressure on the dorsal surface of the foot significantly lower than the pressure exerted by the first portion. The resulting pressure distribution on the dorsal surface of the foot is substantially non-uniform, as the pressure exerted by the first portion is generally higher than the pressure exerted by the second portion. The resulting pressure component along the right-left axis of the tongue from each quarter annular sector of the tongue is mirrored and significantly greater than the case where the inner filler has only the first portion. The resulting pressure distribution results in greater planar stability of the foot, with more pressure being exerted on both sides of the foot.

[0094] Figure 8 A cross section of a tongue of a liner according to an embodiment of the present disclosure is shown in a plane perpendicular to the front-back axis of the tongue of a ski boot, wherein the second portion exerts a pressure on the dorsal surface of the foot significantly lower than the pressure exerted by the first portion. The thickness of the rigid layer having the second portion (7) is at least 4 mm, more preferably 5 mm, and most preferably 6 mm, compensating for the implementation of the second portion (5). Thus, the pressure distribution exerted on the dorsal surface of the foot from each quarter annular sector of the tongue is higher along the right-left axis compared to a tongue having only the first portion, thus increasing the planar stability of the foot.

[0095] Figure 9A cross section of the tongue of the cushion is shown how it deforms along a plane perpendicular to the tongue anterior-posterior axis of the ski boot when the ski boot is tightened according to one embodiment of the disclosure. Finite element analysis (FEA) of the CAD model has been performed showing the structural rigidity of the tongue of the cushion where the deformation of the tongue is measured. By using the support structure (6), the deformation is limited even within the high stress levels of normal use. The deformation here is 0 mm at the lowest stress level measured mainly at the high angle sector of the annulus and 0.08 mm at the lowest stress level measured mainly at the low angle sector of the annulus, which is about 30 times lower than the result measured in the model without the support structure.

[0096] Figure 10 A cross section of the tongue of the cushion is shown how it deforms along a plane perpendicular to the tongue anterior-posterior axis of the ski boot when the ski boot is tightened according to one embodiment of the disclosure. The substantially rigid layer has a first portion (7) and a second portion (8), where the second portion (8) has a thickness of at least 4 mm, more preferably 5 mm, most preferably 6 mm, whereby the rigidity of the tongue is increased. FEA modeling of the CAD design was performed, where the maximum thickness of the second portion of the substantially rigid layer was 5 mm at the annulus a = 0 rad, resulting in substantially small deformation of the tongue. The maximum displacement was 0.59 mm obtained mainly at the low angle sector of the annulus. Thus, increasing the thickness of this particular layer can allow to compensate for the loss of structural integrity due to implementing a second portion having a significant softness.

[0097] Figure 11 A ski boot (9) with a cushion (1) is shown according to one embodiment of the disclosure. The ski boot has closure means such as buckles (12) and velcro straps. The design of the ski boot is such that it is suitable for ski bindings mounted on ski boards. The pressure exerted on the dorsal surface of the foot can be changed to some extent by adjusting the closure of the ski boot, for example, a harder buckle results in a greater pressure exerted on the dorsal surface of the foot. This can be desirable because a greater pressure exerted to the dorsal surface of the foot causes a better energy transfer between the foot and the ski boot (further the edge of the ski board). At the same time, increasing the force exerted on the dorsal surface of the foot also increases the discomfort of the user, especially over a longer time frame, because the arteries of the foot can be impeded and, further, a great pressure can be exerted on the nerves and the blood vessels surrounding them, impeding the function of the nerves.

[0098] Figure 12A cross section along the coronal plane of a tongue (2) of footwear is shown, where the second part (5) is arranged as a cavity. The cavity can function to increase ventilation of the footwear. By arranging the cavity so that it extends towards the outside of the footwear, an air passage (i.e. an air channel or ventilation channel) can be provided between the footwear and the outside to increase ventilation. Furthermore, by using a cavity, the pressure acting on the dorsal surface of the foot during use can be even lower than the pressure exerted on this surface by the second part of the inner padding layer of soft material. The cavity is formed in the second part of the inner padding layer so as to extend in the coronal plane towards the outside of the generally rigid layer (3).

[0099] Figure 13 A cross section along the coronal plane of a tongue (2) of footwear is shown, where the second part (5) is arranged as a cavity, and in addition holes (14) are arranged in the generally rigid layer (3). The second part (inner padding layer) can be arranged as a cavity and / or a breathable material, potentially extending towards the outside of the tongue / footwear. Thus, the second part provides an air passage between the footwear and the outside to increase ventilation, and in addition, can regulate temperature by increasing blood flow. Alternatively or additionally, the air passage can be provided by means of the holes. Thus, the ventilation through the holes (in the generally rigid layer outside) can be a complement to the air passage through the extension of the cavity of the second part (which extension is generally outside the coronal plane). Thus, the second part need not form the air passage alone, but the air passage can be formed together with one or more holes in the generally rigid layer. It should be noted that although not shown in the figure, a support layer can be arranged outside the generally rigid layer outside.

[0100] Figure 14 A foot (22) in footwear (21) is shown, which includes a second part (5) provided as a breathable material (or a cavity), where the second part forms an air passage (13) between a toe portion (19) of the footwear and the outside (15) of the footwear. The function of the support layer (6) is to maintain the overall shape of the tongue (2) of the footwear. Temperature regulation of the foot can be improved by allowing increased blood flow, since the second part covers a portion of the dorsal surface (18) of the foot, where important blood vessels are close to the skin layer, and since the second part forms an air passage between the toe portion and the outside of the footwear, thereby improving ventilation, thereby removing or warming and generally moist air. Thus, generally warm air can be ventilated from the toe portion (19) of the shoe and along the dorsal surface (e.g. from the front (23) of the dorsal surface to the back (24) of the dorsal surface).

[0101] Figure 15A form of footwear is shown in the form of a mountaineering boot (20) in which a second portion (5) of the tongue (2) is provided at least in part in the form of a cavity which extends to the exterior of the footwear. The cavity is arranged so that, in use, an air channel is formed between the interior of the footwear (e.g. the toe portion) and the exterior of the footwear. It can be seen that the air channel is split into two separate air channels, extending towards the edges of the tongue, thereby forming air channels between the interior of the footwear (e.g. the toe portion in use) and the exterior of the footwear. The arrangement of the first and second portions along the interior filler layer (e.g. when viewed along a coronal section of the tongue) is not necessarily constant. Rather, it can be seen from the figures that, along the anterior-posterior axis of the tongue, the second portion (here provided at least in part as a cavity) can be closer to the edges of the tongue, while the first portion is closer to the centre of the tongue.

[0102] Figure 16 A form of footwear is shown in the form of a mountaineering boot (20) in which a second portion (5) of the tongue (2) is provided at least in part in the form of a cavity which extends to the exterior of the footwear. The cavity is arranged so that, in use, an air channel is formed between the interior of the footwear (e.g. the toe portion) and the exterior of the footwear. It can be seen that the air channel is split into two separate air channels, extending towards the edges of the tongue, thereby forming air channels between the interior of the footwear (e.g. the toe portion in use) and the exterior of the footwear. The arrangement of the first and second portions along the interior filler layer (e.g. when viewed along a coronal section of the tongue) is not necessarily constant. Rather, it can be seen from the figures that, along the anterior-posterior axis of the tongue, the second portion (here provided at least in part as a cavity) can be closer to the edges of the tongue, while the first portion is closer to the centre of the tongue.

[0103] Item

[0104] 1. A gaiter for a ski boot, the gaiter comprising a tongue comprising:

[0105] a. an outer substantially rigid layer, the layer being substantially saddle-shaped and substantially conforming to the dorsal surface of a foot;

[0106] b. an inner filler layer provided in contact with the dorsal surface of the foot, the inner filler layer having at least a first portion and a second portion, wherein the second portion is arranged to cover at least a portion of the dorsalis pedis artery on the dorsal surface of the foot, wherein the second portion is more flexible than the first portion; and

[0107] c. a support layer arranged outside the outer substantially rigid layer, the support layer at least partially overlapping the second portion of the inner filler layer.

[0108] 2. The gaiter according to item 1, wherein the second portion is configured to at least partially contact the dorsal surface at which the dorsalis pedis artery is proximal to the epidermis layer.

[0109] 3. The insole according to any of the preceding items, wherein the second portion is arranged so that the pressure exerted on the instep surface where the dorsalis pedis artery is close to the epidermis layer is less than the average pressure exerted by the first portion.

[0110] 4. The insole according to any of the preceding items, wherein the second portion is made of a soft, thermal insulation material, so that the second portion provides climate control and / or comfort to the foot.

[0111] 5. The insole according to any of the preceding items, wherein the second portion is arranged so that the pressure exerted on the instep surface where the deep peroneal nerve is close to the epidermis layer is less than the average pressure exerted by the first portion.

[0112] 6. The insole according to any of the preceding items, wherein the second portion is configured to have a symmetry axis that substantially overlaps with the anterior-posterior central axis of the instep surface when the tongue is arranged on the foot.

[0113] 7. The insole according to any of the preceding items, wherein the second portion is configured to exert lower pressure locally along the anterior-posterior central axis of the instep surface.

[0114] 8. The insole according to any of the preceding items, wherein the first portion is configured to exert higher pressure along the anterior-posterior axis on the peripheral part of the instep surface.

[0115] 9. The insole according to any of the preceding items, wherein the first portion and the second portion are configured to provide increased planar stability of the foot.

[0116] 10. The insole according to any of the preceding items, wherein the total area of the support layer is greater than the total area of the second portion.

[0117] 11. The insole according to any of the preceding items, wherein the total area of the support layer is between the total area of the second portion and the total area of the outer, substantially rigid layer.

[0118] 12. The insole according to any of the preceding items, wherein the total area of the support layer is at least half the area of the second portion, preferably the same as the area of the second portion, more preferably 3 times the area of the second portion, most preferably 4 times the area of the second portion.

[0119] 13. The insole according to any of the preceding items, wherein the material of the second portion is chosen so that the pressure exerted by the second portion to the instep area in the position mounted on the foot is less than 100 kPa, preferably less than 70 kPa, even more preferably less than 50 kPa, most preferably less than 30 kPa.

[0120] 14. The insole according to any of the preceding items, wherein the material of the second portion is chosen such that the second portion exerts a pressure to the dorsal area of the foot near the epidermis layer of the dorsalis pedis artery in a position mounted on a foot of less than 100 kPa, preferably less than 70 kPa, even more preferred less than 50 kPa, most preferred less than 30 kPa.

[0121] 15. The insole according to any of the preceding items, wherein the material of the first portion is chosen such that the first portion exerts a pressure to the foot of at least 30 kPa, preferably 50 kPa, more preferred 70 kPa, even more preferred at least 100 kPa in a position mounted on a foot.

[0122] 16. The insole according to any of the preceding items, wherein the support layer is made of metal, such as steel.

[0123] 17. The insole according to any of the preceding items, wherein the support layer is made of Kevlar, fiberglass or a synthetic material.

[0124] 18. The insole according to any of the preceding items, wherein the second portion is made of a synthetic material, such as ethylene-vinyl acetate (EVA) or low-density polyethylene (LDPE).

[0125] 19. The insole according to any of the preceding items, wherein the first portion is made of a synthetic material, such as ethylene-vinyl acetate (EVA) or low-density polyethylene (LDPE).

[0126] 20. The insole according to any of the preceding items, wherein the substantially rigid layer is made of a synthetic material, such as acrylonitrile butadiene styrene (ABS) or low-density polyethylene (LDPE).

[0127] 21. The insole according to any of the preceding items, wherein the area of the second portion is between 1% and 20%, preferably 1% and 10%, most preferred 1% and 5% of the area of the inner filler of the tongue.

[0128] 22. The insole according to any of the preceding items, wherein the tongue is additionally configured to further contact the lower part of the leg.

[0129] 23. A tongue for footwear, the tongue comprising:

[0130] a. an outer, substantially rigid layer, the layer being substantially saddle-shaped and substantially conforming to the dorsal surface of a foot;

[0131] b. an inner filler layer providing contact with the dorsal surface of a foot, the inner filler layer having at least a first portion and a second portion, wherein the second portion is arranged to cover at least a part of the dorsalis pedis artery on the dorsal surface of the foot, wherein the second portion is softer than the first portion; and

[0132] c. a support layer arranged outside the outer substantially rigid layer, the support layer at least partly overlapping the second portion of the inner filler layer.

[0133] 24. A footwear, such as a sports shoe, preferably a ski boot, comprising a gusset according to any of the items 1 to 24.

[0134] 25. The footwear according to item 25, wherein the footwear is a ski boot, or a cross-country ski boot, or a flexion rotation ski boot, or an alpine ski boot, or a freeride ski boot, or a snowboard boot, or a skateboard boot, or a water ski boot, or a skate boot, or a touring skateboard boot, or a hiking boot, or a trail boot, or a running shoe, or a sports shoe, or a work shoe, or a boot, or a mountain boot, or an orthopedic shoe, or a shoe.

[0135] 26. A gusset for a ski boot, the gusset comprising a gusset comprising:

[0136] a. an outer substantially rigid layer, the layer being substantially saddle-shaped and substantially conforming to a dorsal surface of a foot,

[0137] b. an inner filler layer providing contact with the dorsal surface of the foot, the inner filler layer having at least a first portion and a second portion,

[0138] wherein the second portion is arranged to cover at least a portion of the dorsalis pedis artery and / or the deep peroneal nerve on the dorsal surface of the foot, and wherein the second portion is softer than the first portion,

[0139] and wherein the outer substantially rigid layer has a first part and a second part, wherein the second part has a thickness of at least 3 mm, more preferably 4 mm, even more preferably 5 mm, most preferably 10 mm, over the area of the second portion.

[0140] 27. The gusset for a ski boot according to item 27, comprising a gusset according to any of the items 1 to 24.

[0141] 28. The gusset for a ski boot according to any of the preceding items, wherein the average thickness of the second part of the substantially rigid layer is thicker than the first part of the substantially rigid layer.

Claims

1. A tongue for footwear, the tongue comprising: a. an outer substantially rigid layer, the outer substantially rigid layer comprising a first portion and a second portion, the outer substantially rigid layer being substantially saddle-shaped and generally conforming to a dorsal surface of a foot portion; and b. an inner filler layer providing contact with the dorsal surface of the foot portion, the inner filler layer having at least a first portion and a second portion; wherein the second portion is configured as a cavity and is arranged to cover at least a portion of a deep peroneal nerve and / or a dorsal artery of the dorsal surface of the foot portion; wherein the second portion extends along an anteroposterior axis of the foot portion; wherein the second portion has an area of 1% to 20% of an area of the inner filler layer; and wherein the second portion is thicker in an area covering the second portion than the first portion.

2. The tongue for footwear according to claim 1, wherein, The outer substantially rigid layer comprises a through hole.

3. Tongue for footwear according to any of the preceding claims, wherein, The second portion has a thickness of at least 3 mm over the area of the second portion.

4. The tongue for footwear according to claim 1 or 2, wherein, The second portion is configured to cover an area of the dorsal surface of the foot portion where the dorsal artery is proximal to an epidermis layer.

5. The tongue for footwear according to claim 1 or 2, wherein, The second portion is configured to exert a lower average pressure on the dorsal surface of the foot portion than the first portion.

6. The tongue for footwear according to claim 1 or 2, wherein, The first portion is configured to exert a higher pressure to a peripheral portion of the foot portion to increase planar stability.

7. The tongue for footwear according to claim 1 or 2, wherein, The second portion is configured to have a symmetry axis substantially overlapping an anteroposterior central axis of the dorsal surface of the foot portion when the tongue is arranged on the foot portion.

8. Footwear comprising the tongue according to any one of claims 1 to 7.

9. The footwear of claim 8, wherein, The footwear is a boot, a shoe or an insole for a ski boot.

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