Device and method for foot massage

Abstract

The foot massage device (10) is designed to be positioned under all or part of the foot (5) and at least under the arch of the foot. The front surface of the device includes a plurality of solid protrusions (12) intended to contact the arch of the foot to exert pressure that can improve venous return, each protrusion having a base, a top, a height, and a shape that determines the volume occupied by the protrusion. The protrusions are made of a soft, incompressible or moderately compressible material with a Poisson's coefficient greater than 0.30 and are shaped and positioned such that flattening of the protrusions causes them to expand and fill all or part of the volume between each of the protrusions, significantly increasing the surface area of ​​the device in contact with the foot.

Description

[Technical Field]

[0001] The present invention relates to a foot massage device designed to be positioned under all or part of the foot, and at least under the arch of the foot, and to a method of massaging the foot using such a device. [Background technology]

[0002] It is known to manufacture insoles with means for exerting a massaging action on areas of the foot to aid or enhance the function of the plantar pump.

[0003] Known in particular from US Pat. No. 7,380,352 or EP Pat. No. 0,971,606 are orthopedic insoles comprising a plurality of cushioned layers arranged on the insole surface, including a first cushioned layer in the forefoot joint area, a second cushioned layer in the transition zone between the midfoot and the tarsus, and a third cushioned layer in the midfoot transition zone.

[0004] Through Canadian Patent No. 2827485 or WO 2012 / 110763, a shoe is also known that comprises an upper, a blood flow stimulation element, and a sole element, the sole element incorporating a fluid pump, a fluid reservoir that can be used to receive fluid at high pressure from the pump via a first valve, and a second valve that can be used to activate the blood flow stimulation element under the control of a processor.

[0005] Sandals or insoles with protrusions, which are marketed under various brands and are supposed to have a foot massage function, are also known. In particular, WO2019209642(A1) describes a massage insole with protrusions whose bending causes a foot massage effect. This document teaches that the flexibility and shape (height and width) of the protrusions can be adjusted to encourage the protrusions to bend, thereby maximizing the massage effect.

[0006] The documents US Patent Application Publication No. 20070234593(A1), GB Patent Application Publication No. 2303780(A) and US Patent Application Publication No. 20190142107(A1) further describe insoles with protrusions or hollow protrusions that supposedly provide a massaging effect and at least comfort.

[0007] It would be desirable to provide a foot massage device to be placed under the foot that offers better performance than known devices in terms of stimulating the plantar pump. Summary of the Invention

[0008] An embodiment relates to a foot massage device designed to be positioned under all or part of the foot and at least under the arch of the foot, comprising a front surface designed to be in contact with the foot, the front surface of the device including a plurality of solid protrusions intended to contact the arch of the foot to exert pressure that can improve venous return, each protrusion having a base, a top, a height, and a shape that determines the volume occupied by the protrusion. The protrusions are made of a soft, incompressible or moderately compressible material with a Poisson's coefficient greater than 0.30, and are shaped and positioned such that flattening of the protrusions causes them to expand and fill all or part of the volume between each of the protrusions, significantly increasing the surface area of ​​the device in contact with the foot.

[0009] According to one embodiment, in at least one region of the device, the protrusions are shaped and arranged such that a 50% reduction in their height causes the protrusions to spread and fill the volume between each of the protrusions by at least 60%.

[0010] According to one embodiment, at least in the arch region of the device, the protrusions are shaped and arranged such that a 50% reduction in their height causes the protrusions to expand and fill the volume between each of the protrusions at least 90%.

[0011] According to one embodiment, the projections are made of a material having a Shore A hardness of between 5 and 40 measured according to ISO 48-4.

[0012] According to one embodiment, the lugs have a height that increases as they approach the maximum arch area of ​​the foot.

[0013] According to one embodiment, the protrusion has, between its base and its top, a constant or variable height comprised between 1.5 mm and 25 mm.

[0014] According to one embodiment, the device is designed to cover the heel and also the sole of the foot, and includes protrusions in at least the area of ​​the forefoot corresponding to the metatarsophalangeal line and at least around the circumference of the heel.

[0015] According to one embodiment, the protrusions are substantially hemispherical in shape and have a height comprised between 0.25 and 2.5 times the width of the base of the protrusion.

[0016] According to one embodiment, at least in the arch region of the device, the spacing between two protrusions is comprised between 0.1 and 0.5 times the width of the protrusions or the average of the respective widths of the protrusions if the protrusions are not identical.

[0017] According to one embodiment, the protrusions are made of an elastomeric material.

[0018] According to one embodiment, the protrusions are made of a material selected from the group comprising styrene-ethylene-butylene-styrene, silicone gel, in particular polydimethylsiloxane, polyurethane foam, ethylene-vinyl acetate foam, polyvinyl chloride, and EPDM rubber.

[0019] According to one embodiment, the device comprises a base designed to support at least the heel and arch of the foot, and a soft layer assembled on the rigid base and on which the protrusions are formed.

[0020] According to one embodiment, the base is thermoformable at a temperature comprised between 60°C and 80°C.

[0021] According to one embodiment, the base is made of a material included in the group including polycyclohexylene dimethylene terephthalate glycol, polyethylene terephthalate glycol, polycaprolactone, polylactide-type polyester, ethylene-vinyl acetate, polyurethane, polyethylene, polypropylene, and thermoformable resins.

[0022] Embodiments also relate to methods of making and shaping such devices, comprising the initial step of producing a device having a base with a predetermined shape at its ends, and thermoforming the base to conform its arch region to the shape of a user's foot, the thermoforming step comprising the steps of bringing the device to a thermoforming temperature, for example by immersion in boiling water, applying the device to the foot while the device is still hot and still within the thermoforming temperature range, and exerting pressure under the device in the arch region to thermoform the device to the shape of the arch of the foot.

[0023] Embodiments also relate to a method of manufacturing such a device by two-material injection molding in a mold that includes a first impression designed to receive, by injection molding, the material that will form the base of the device, and a second impression that will receive the material that will form the soft layer after the base has been injection molded.

[0024] Embodiments also relate to a method of non-therapeutic foot massage using a device designed to be positioned under all or part of the foot and at least under the arch of the foot, the device having a front surface designed to be in contact with the foot, the method comprising providing on the front surface of the device a plurality of solid protrusions intended to contact the arch of the foot to apply pressure that can improve venous return, each protrusion having a base, a top, a height, and a shape that determines the volume occupied by the protrusion, the protrusions being made of a soft, incompressible or moderately compressible material having a Poisson's coefficient greater than 0.30, and shaped and arranged such that flattening of the protrusions causes them to expand and fill all or part of the volume between each of them, significantly increasing the surface area of ​​the device in contact with the foot, the method comprising a first stage of blood evacuation due to localized pressure of each protrusion against an area of ​​the foot facing it, and a second stage of blood evacuation after deformation of the protrusions under the influence of pressure applied by the foot, the compressed protrusions together forming an increased surface that applies venous return pressure against areas of the foot not desired during the first stage of blood evacuation.

[0025] According to one embodiment, the method includes providing protrusions in at least one region of the device, the protrusions being shaped and arranged such that a 50% reduction in their height causes the protrusions to expand and fill the volume between each of the protrusions by at least 60%.

[0026] According to one embodiment, the method includes providing protrusions in at least the arch region of the device, the protrusions being shaped and arranged such that a 50% reduction in their height causes the protrusions to expand and fill at least 90% of the volume between each of the protrusions.

[0027] According to one embodiment, the projections are made of a material having a Shore A hardness comprised between 5 and 40, measured according to ISO 48-4.

[0028] According to one embodiment, the lugs are provided with an increasing height as they approach the maximum arch area of ​​the foot.

[0029] According to one embodiment, the projection is provided with a constant or variable height between its base and its top comprised between 1.5 mm and 25 mm.

[0030] According to one embodiment, the device is designed to cover the heel and also the sole of the foot, and the method also includes providing protrusions in at least the area of ​​the forefoot corresponding to the metatarsophalangeal line and at least around the circumference of the heel.

[0031] According to one embodiment, the projections are given a substantially hemispherical shape and a height comprised between 0.25 and 2.5 times the width of the base of the projection.

[0032] According to one embodiment, at least in the arch region of the device, two protrusions are separated by a spacing comprised between 0.1 and 0.5 times the width of the protrusions or the average width of each of the protrusions if the protrusions are not identical.

[0033] According to one embodiment, the protrusions are realized in an elastomeric material. [Brief explanation of the drawings]

[0034] Examples of embodiments of massage devices and methods are described below in a non-limiting manner with reference to the accompanying figures. [Figure 1] 1 is a partial cross-sectional view of an exemplary embodiment of a device. [Figure 2] 2 shows the device of FIG. 1 facing a portion of a foot. [Figure 3] 2 shows a first stage of foot compression for the device of FIG. 1; [Figure 4] 2 shows a second stage of foot compression for the device of FIG. 1; [Figure 5] A method for calculating the dimension design of the device of FIG. 1 is shown. [Figure 6] A method for calculating the dimension design of the device of FIG. 1 is shown. [Figure 7] 2 illustrates an exemplary embodiment of the device of FIG. 1. [Figure 8] 2 illustrates an exemplary application of the device of FIG. 1 in the manufacture of insoles. [Figure 9] The insole of FIG. 8 is shown in a right side view. [Figure 10] The insole of FIG. 8 is shown in a left side view. [Figure 11] 2 illustrates another exemplary application of the device of FIG. 1. [Figure 12] 9 shows a manufacturing process for the insole of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0035] The plantar pump ensures the return of blood contained in the venous sole to the heart by compressing the soft tissues of the foot when weight is applied to it. From an anatomical perspective, the foot can actually be considered a "reservoir" of the blood network located at the end of the lower leg, because the foot is traversed primarily at the plantar level by a particularly well-developed network of superficial and deep veins, commonly referred to as the "venous sole." The two mechanisms, the plantar pump and the muscle pump, work in concert with the foot rotation phase, and the initiation of venous return from the lower leg is initiated by the activation of the plantar pump when the foot contacts the ground and supports weight. The compression of the soft tissues of the plantar sole expels blood from the venous sole toward the foot and upper leg. This initiation occurs from the step attack phase to the lift-off phase of the contralateral foot. The foot muscle pump then takes over, followed directly by the calf muscle pump. Contraction of the muscles necessary to stabilize the foot and then propel the body forward, particularly the foot and calf muscles, causes compression of the veins that traverse these muscles. This action allows blood to be expelled from the foot toward the calf and then toward the top of the leg. This phenomenon occurs from the middle of the simple support phase until the foot is released. During the so-called oscillation phase, the venous sole is refilled with blood due to the action of gravity and the centrifugal force generated by the leg movement.

[0036] It is known that massaging the soles of the feet helps to limit venous congestion by effectively compressing the veins and circulating blood. Nevertheless, massage cannot be performed while the individual is engaged in daily activities and requires the intervention of another person. Here, a massage device is proposed that applies localized pressure movements at several points on the soles of the feet, followed by pressure point movements, as occurs during manual massage, to expel blood from the soft tissue more effectively than known devices. Such a device is essentially intended to be placed under the arch of the foot, but can also be used to act on other areas of the foot.

[0037] An example of such a device 10 is shown in partial cross section in Figure 1. Device 10 is designed to be positioned under all or part of the foot, and at least under the arch of the foot. Device 10 includes a layer 11 of soft, incompressible or moderately compressible material, the anterior surface of which includes a plurality of projections 12 intended to contact the plantar surface of the foot to exert pressure that can improve venous return. Each projection 12 has a base 120 (shown in dotted lines), a top 121, a height h, and a shape (here hemispherical) that determines the volume occupied by the projection for that given height h.

[0038] The protrusions 12 have a constant or variable height h between their base and their apex, preferably between 1.5 mm and 5 mm, but which can reach 25 mm in certain embodiments. In the illustrated embodiment, the protrusions 12 are of uniform height. Due to the flexibility of the material forming layer 11, the protrusions 12 are perceived as "soft" when pressed with a finger. The protrusions are shaped and positioned such that flattening of the protrusions under foot movement causes the protrusions to expand, filling all or part of the empty volume between each of the protrusions and significantly increasing the surface area of ​​the device 10 in contact with the foot. More specifically, the function of the protrusions 12 is to use the user's weight to perform a massage-like action on the soles of the feet, as better understood with reference to FIGS. 2-4.

[0039] Figure 2 shows device 10 at a moment when foot 5 is not yet exerting pressure against process 12. Figure 3 shows device 10 at a moment when foot 5 begins to press against process 12, and Figure 4 shows device 10 at a moment when foot 5 exerts maximum compressive force against process 12. In these figures, reference numeral 52 indicates the soft tissue of plantar 51, and reference numeral 53 indicates the bony structures of foot 5 that are covered by soft tissue 52. Veins plantar 50 are diagrammed by horizontal veins 50a extending within soft tissue 52 and a set of vertical veins 50b ascending toward the heart.

[0040] The projections 12 act to compress the soft tissue 52 of the plantar surface very deeply and locally in a first stage, as would be done during a massage by pressing the fingers against the area to be massaged, and in a second stage, due to their low hardness, which is preferably adapted to that of the soft tissue, they flatten and spread under the prolonged action of the body weight, "expelling" the blood located between the projections 12 from the soft tissue, as would be done during a massage by moving the fingers.

[0041] Thus, after the pre-support steps of FIG. 2, the device 10 performs the following steps. a first stage of blood evacuation by local pressure of each projection 12 on the area of ​​the foot facing it, as shown in FIG. 3, then - The second stage of blood evacuation after deformation of the protrusion 12 under the influence of pressure exerted by the foot, shown in Figure 4.

[0042] During the second phase, the protrusions 12 flatten and widen, filling all or part of the space between each of the protrusions. This expansion significantly increases the surface area of ​​the device 10 in contact with the foot, so that the compressed protrusions together form an increased surface area that exerts venous return pressure, as indicated by the arrows, on areas of the foot not desired during the first phase of blood evacuation.

[0043] Thanks to the device 10, each portion of the plantar surface 51 is compressed during the second phase, expelling blood present there. Such a massage effect cannot be achieved with protrusions that bend under pressure, causing a massage effect unrelated to that described herein and even resulting in an uncomfortable floating effect under the foot. In fact, conventional bending protrusions generate localized static pressure that lacks the deformation required to expel blood located between them. Therefore, the massage action performed by each protrusion 12 on the area of ​​the foot facing it can be analyzed as a combination of localized pressure and subsequent movement. Such movement helps to better "expel" blood from soft tissues and veins, significantly improving the effectiveness of the plantar pump massage compared to known massage devices.

[0044] Various parameters that may be considered by one skilled in the art for the implementation of device 10 are now described, in particular the flexibility of the material forming the protrusions, the compressibility of the material forming the protrusions, the nature of the material forming the protrusions, the shape of the protrusions, the arrangement and spacing between the protrusions, and the height of the protrusions.

[0045] To achieve the deep massage effect described above, the material forming layer 11 must be neither too hard nor too soft. A soft material will collapse too quickly and not penetrate into the soft tissue 52 of the plantar surface. Conversely, a material that is too hard will penetrate the soft tissue 52 easily but will not spread to create the increased surface area described above that exerts venous return pressure on areas of the foot that are not desired during the first phase of blood evacuation. Therefore, a soft material is preferably selected that has a hardness greater than that of the soft tissue. According to tests and calculations performed by the applicant, a material having a Shore A hardness between 5 and 60, preferably between 5 and 40, as measured according to ISO 48-4, allows for effective deformation of the plantar surface during the first phase of blood evacuation, while being able to spread during the second phase of blood evacuation.

[0046] Furthermore, to achieve the aforementioned increased surface area for exerting venous return pressure on areas of the leg not required during the first phase of blood drainage, the material forming layer 11 should not be excessively compressible; otherwise, protrusions 12 would not expand to fill all or part of the space between them. Ideally, for maximum expansion, the material forming layer 11 should be completely incompressible and therefore have a Poisson's coefficient equal to 0.5. While such materials do not exist in practice, some ideal isotropic polymers approach this value. Tests and calculations performed by the applicant indicate that a material with a Poisson's coefficient greater than 0.30 (i.e., a compressibility of less than 50%) allows the device to be implemented in conjunction with judicious selection of the protrusion's shape. For example, if the Poisson's coefficient of the material used is closer to 0.3 than 0.5, it may be advantageous to give the protrusions a shape that allows them to occupy the largest possible volume for a given height h and a given width l of their base, in order to take into account their partial compressibility.

[0047] Many different materials are likely to meet the packaging requirements of device 10 in terms of flexibility and low compressibility. In one embodiment, layer 11 is realized in an elastomeric material. More generally, studies carried out by the applicant have shown that the following list of materials is suitable: - styrene-ethylene-butylene-styrene (SEBS), or "SEBS", silicone gels, in particular polydimethylsiloxane, or "PDMS", - polyurethane foam, or "PU", - ethylene-vinyl acetate foam, or "EVA", - Ethylene-propylene-diene monomer rubber, known as "EPDM" -polyvinyl chloride, A material selected from the following may be used.

[0048] To obtain the desired massage effect, the flattening and expansion of the protrusions should fill all or part of the space between each of the protrusions to obtain an increased surface area for exerting venous return pressure on areas of the leg not desired during the first stage of blood evacuation. Therefore, in addition to providing a material that is not very compressible, too large a space between each of the protrusions should be avoided, otherwise the protrusions will not be able to fill the empty volume separating them. By theoretical or simulation calculations of the occupancy of the empty volume under different situations of compression of the protrusions, a person skilled in the art can determine the following, namely: -shape - Compressibility and hardness of the materials used - and the pressures decided upon, Depending on this, it becomes possible to determine the optimum spacing between the protrusions.

[0049] It should be noted here that this shape can vary considerably while respecting the above constraints: thus, in addition to the hemispherical shape, which is easy to produce industrially, the skilled person can choose protrusions that are cylindrical, pyramidal, round, have a triangular or square base, semi-ellipsoidal, etc.

[0050] However, in some embodiments, a substantially hemispherical projection shape may be preferred, which may be defined by a height comprised between 0.25 and 2.5 times the width of the base of the projection, i.e., a shape with a rounded top where the height to width ratio does not exceed the aforementioned limit of 2.5, so that the projection does not buckle (i.e., bend) under pressure exerted by the foot.

[0051] 5 and 6 show an exemplary mathematical approach for determining the optimal spacing between equally sized and equidistant hemispherical protrusions. In these figures, "D" is the distance between the centers of the protrusions, "e" is the distance separating the protrusions (edge-to-edge distance), "r" is the radius of the protrusions, which is also the height h of the protrusions (not shown), and "l" is the width of the base of the protrusions, which here is twice the radius r of the protrusions. This can be written as follows: D=2 *r+e

[0052] To determine the distance "e", the assumption is made that the empty volume between the protrusions must be completely filled when they are partially crushed, and the protrusions are assumed to be composed of a pseudo-incompressible material. According to this assumption, the distance "e" is found so that the volume occupied by the protrusions is equal to the empty volume separating them. The equality of volumes results in the following equation:

[0053]

number

[0054] This can be seen as a quadratic equation with three parameters a, b, and c. cr 2 +br+a=0

[0055] It is deduced as follows: Δ=b 2 -4ac Δ>0

[0056]

number

[0057] This example shows that the empty volume separating the protrusions when they are subjected to a given crush can be filled entirely at a distance equal to 0.2 times the radius of the protrusions or 0.1 times the width "l" of the base of the protrusions, the effect being that the material comprising the protrusions is distributed over the entire surface of layer 11.

[0058] According to another approach, a collapse of the projections corresponding to a predetermined reduction in projection height, for example a 50% reduction in projection height, is considered, and a spacing between the projections is determined that corresponds to a filling rate of less than 100% of the empty volume separating the projections when the projections are collapsed at a 50% reduction in their height. In fact, to obtain the desired massage effect, it is not necessarily necessary that no empty space is left over for the increased surface to exert venous return pressure on areas of the leg that are not desired during the first phase of blood evacuation.

[0059] Therefore, in accordance with the approach recommended by the applicant, the projections or portions thereof are shaped and positioned such that a 50% reduction in their height will cause the projections to expand and fill the volume between each projection to a rate of at least 60%. In a preferred embodiment, this volume filling is at least 90% in the arch region for a 50% reduction in projection height.

[0060] Calculations made according to this approach show that for hemispherical or substantially hemispherical protrusions, the spacing between two protrusions should preferably be comprised between 0.1 and 0.5 times the width of the protrusions or, if the protrusions are not identical, the average value of their respective widths.

[0061] As mentioned above, the projections 12 of the device 10 are intended to be positioned at least below the arch of the foot. In the absence of foot pressure, the projections must be in contact with or very close to the foot to initiate the first stage of blood evacuation shown in FIG. 3 from the moment the foot first contacts the ground. In other words, the apex 121 of the projections 12, or the majority of the projections extending below the arch of the foot, must be in contact with or very close to the foot. For this purpose, several embodiments of the device can be envisioned.

[0062] In a first embodiment, layer 11 is assembled on a non-thermoformable, flat-shaped, rigid base designed to support at least the heel and arch of the foot, and optionally the forefoot, with the projections having heights that increase as they approach the maximum arch area of ​​the foot, so that the apex of each projection is as close as possible to the soft tissue of the arch of the foot.

[0063] In a second embodiment, layer 11 is assembled on a flat, but thermoformable, rigid base designed to support at least the heel and arch of the foot, and optionally the forefoot. In this case, the projections may all be of the same height, as the rigid base is thermoformed to accommodate the shape of the user's foot. In this case, the top of each projection will be very close to the soft tissue of the arch of the user's foot, thanks to the shape imparted to the base.

[0064] In a third embodiment, layer 11 is assembled on a rigid or non-rigid base that has been pre-heat-molded to adapt to the shape of the user's foot. This can be an insole made to measure from the foot's imprint, for example an orthopedic insole made by a podiatrist from cork, foam, or high-density latex. In this case, as mentioned above, the projections can all be of the same height, unless the doctor wishes to treat a specific area of ​​the foot's arch.

[0065] Various other embodiments can be provided by combining the above-mentioned embodiments. For example, layer 11 can be associated with an anatomically shaped rigid base that is thermoformable or thermoformed from a model of a typical arch of the foot without being specifically adjusted to the determined shape of the user's foot (general anatomical shape). In this case, the protrusions can also have a height that increases as they approach the maximum arch area of ​​the foot, but to a lesser extent than in the first embodiment.

[0066] An exemplary embodiment of device 10 is shown in a top view in Figure 7. In this embodiment, layer 11 is designed to cover the arch of the foot as well as the heel and forefoot, i.e., here the entire foot except for the central heel region. Layer 11 here comprises hemispherical projections. Thus, projections that appear to have a wider base than others when viewed from above are projections of greater height.

[0067] Layer 11 includes a first set of protrusions 12 with increasing height as they approach the foot's arch region, and a second set of protrusions 13 extending across an area corresponding to the heel periphery. The height of the protrusions 13 increases as they approach the heel periphery, but does not reach the same height as the protrusions 12 located opposite the foot's arch region. Layer 1 also includes protrusions 14 in the forefoot region corresponding to the metatarsophalangeal line, presenting a row of protrusions 14 along this line that are higher than the protrusions in the adjacent row but lower than the protrusions 12 located opposite the foot's arch region. Finally, layer 11 includes multiple other protrusions of lower height across the remainder of its surface, the "massaging" effect of which is less than that of protrusions 12, 13, and 14, but is not considered uninteresting.

[0068] FIGS. 8, 9, and 10 show an exemplary application of the device to the realization of an insole 30, respectively, in bottom, right, and left side views. Insole 30 includes layer 11 of FIG. 7 assembled on a rigid base 20. Base 20 covers the heel and arch of the foot without covering the forefoot region. The base optionally includes an orifice 21 in the central heel region through which layer 11 is visible, corresponding to the non-protruding portion of layer 11 (FIG. 13). Here, rigid base 20 has an anatomical shape and is preformed or shaped to correspond to the general shape of the foot. Thus, the base provides a bearing surface for layer 11 that is not flat but includes protuberances 22, particularly in the arch region. Thus, here, the protuberance of layer 11 due to base 20 in the arch region is combined with an increased height of protuberances 12 in this same region. In certain embodiments, the shape of the base 20 may additionally be adjusted by thermoforming to perfectly fit the user's foot.

[0069] In the variation shown in Figure 11, layer 11 includes only protrusions 12 of the same shape and height. Layer 11 is associated with an anatomically shaped rigid base that preferably exhibits a stronger arch in the arch region than insole base 20 shown in Figures 8-10 and, in certain embodiments, can be adjusted to the shape of a given user's foot by thermoforming.

[0070] In an advantageous embodiment, the rigid base 20 is thermoformable at temperatures comprised between 60°C and 80°C and is adjusted to the shape of the user's foot according to a simple and inexpensive process. According to this process, an insole 30 of the type shown in Figures 8 to 10 is manufactured industrially by first giving the base 20 a substantially flat shape or an anatomical shape with a curvature corresponding to the general shape of the foot. If the base has a flat shape or if its general anatomical shape does not perfectly fit the user, the base 20 can be thermoformed by the user himself to finely adjust it to the user's foot. This process is carried out by the user as follows: the insole 30 is brought to the thermoforming temperature of the base 20, for example by immersing it in boiling water; the user applies the insole to the foot while the insole is still hot and still within the thermoforming temperature range of the base 20, for example between 60 and 80°C; The user then exerts pressure under the base 20 in the arch area to give the base the shape of the arch of their foot. Tests have shown that if the temperature of the insole is on the order of 75°C or less, it is not necessary to protect the user's foot with an isothermal sock during the thermoforming stage. In other embodiments, the base can be thermoformed by a heated mold containing an impression of the user's foot.

[0071] The base 20 can be realized using a variety of materials, some of which may be provided as thermoformable in the temperature ranges mentioned above. These include, among others: - polycyclohexylene dimethylene terephthalate glycol, or "PCTG", -Polyethylene terephthalate glycol, or "PETG", - Polycaprolactone, or "PCL", - Polylactide type polyester, or "PLA", - ethylene vinyl acetate, or "EVA", - Polyurethane, or "PU", -Polyethylene "PE", Polypropylene or "PP", or even -Thermoformable resin.

[0072] In one embodiment, the insole 30 shown in Figures 8 to 10 or any other variant thereof is manufactured by a two-material injection molding process in a mold with two impressions. This process makes it possible to realize a thermoformable or non-thermoformable base 20 with any desired shape. This is done by means of a first material M1 that allows the manufacture of the base 20 and a second material M2 that allows the manufacture of the layer 11. Examples of such materials M1 and M2 are given above.

[0073] A two-material injection molding machine is shown diagrammatically in cross section in Figure 12. The machine includes a first injection line 510 connected upstream to a hopper (not shown) that receives granules of a first material M1. The line 510 includes a heating collar that controls the softening of the material M1 and a rotating screw that pushes the softened material M1 in a pasty state towards the first injector 61. A second injection line 520, of the same structure as the first injection line, is connected upstream to a hopper (not shown) that receives granules of a second material M2, and the line 520 conveys the pasty material M2 towards the second injector 62.

[0074] The machine also includes a mold 70 containing a first impression 71 having the desired shape of the base 20 and a second impression 72 having the desired shape of the layer 11 assembled on the base 20, i.e., the shape of the insole 30 to be produced. To make the illustration easier to read, the two impressions are represented here diagrammatically by arbitrary shapes. The mold 70 also includes an injection channel 81 for the material M1 into the impression 71, the inlet of which is connected to the outlet of the injector 61, and an injection channel 82 for the material M2 into the impression 72, the inlet of which is connected to the outlet of the injector 62.

[0075] The machine also includes a rotating part 90 with sliding ejection fingers 91, 92. Once the material M1 has been injected into the first impression 71, the rotating part 90 allows the base 20 to be placed in the second impression 72, so that the base can be covered with the material M2. To this end, the rotating part 90 is moved away from the mold 70 to remove the base 20 from the first impression 71, then performs a half-turn to bring the base 20 in front of the second impression 72, and then is again moved toward the mold 70 to insert the base 20 into the second impression 72. Although not visible in the figure, the rotating part 90 includes microcavities on the opposite side of each impression 71, 72 into which the material M1 enters, thus creating microlinks that allow the base 20 to remain attached to the rotating part 90 during its transport to the impression 72. After the material M2 has been injected into the impression 72, the rotating part 90 is again moved away from the mold 70 and the sliding fingers 91, 92 push the base 20 forward, breaking the micro-links holding the base 20 to the part 90 and thus ejecting the insole 30.

[0076] The two materials M1, M2 are injection molded in a paste state at high temperature, so that a chemical bond is formed between the base 20 and the layer 11, ensuring a total bond. It should be noted that the injection molding steps of materials M1 and of materials M2 may be simultaneous, which makes it possible to double the production speed, with the base 20 being realized by injection molding while the layer 11 is injection molded onto the previously realized base 20, the insole 30 being ejected from the part 90 before each of its revolutions.

Claims

1. A foot massage device (10, 11, 20, 30) designed to be positioned under all or part of a foot (5) and at least under the arch of said foot, said device having a front surface designed to be in contact with said foot, - the front face of the device comprises a plurality of solid protrusions (12) intended to come into contact with the arch of the foot in order to exert a pressure capable of improving venous return, each protrusion having a base (120), a top (121), a height (h) and a shape that determines the volume occupied by said protrusion; - the protrusions are made of a soft, incompressible or moderately compressible material with a Poisson's coefficient greater than 0.30, and are shaped and positioned such that flattening of the protrusions causes them to expand and fill all or part of the volume between each of the protrusions, significantly increasing the surface area of ​​the device in contact with the foot; A foot massage device (10, 11, 20, 30) characterized by:

2. 2. The device of claim 1, wherein in at least one region of the device, the protrusions (12) are shaped and arranged such that a 50% reduction in their height causes the protrusions to expand and fill the volume between each of the protrusions by at least 60%.

3. 3. The device of claim 1, wherein at least in the arch region of the device, the protrusions (12) are shaped and arranged such that a 50% reduction in their height causes the protrusions to expand and fill the volume between each of the protrusions by at least 90%.

4. A device according to any one of claims 1 to 3, wherein the protrusions are made of a material having a Shore A hardness comprised between 5 and 40, measured according to ISO 48-4.

5. A device according to any one of claims 1 to 4, wherein the projections have a height (h) that increases as they approach the maximum arch region of the foot.

6. A device according to any one of the preceding claims, wherein the protrusion has, between its base and its apex, a constant or variable height (h) comprised between 1.5 mm and 25 mm.

7. 7. A device according to any one of claims 1 to 6, designed to cover the heel and also the sole of the foot, and comprising protrusions (13, 14) at least in the region of the forefoot corresponding to the metatarsophalangeal line and at least around the circumference of the heel.

8. 8. The device according to any one of the preceding claims, wherein the protrusions are substantially hemispherical in shape and have a height (h) comprised between 0.25 and 2.5 times the width (l) of the base (120) of the protrusion.

9. 9. A device according to any one of the preceding claims, wherein at least in the arch region of the device, the spacing between two protrusions is comprised between 0.1 and 0.5 times the width (l) of the protrusions or the average of the respective widths of the protrusions if the protrusions are not identical.

10. The device of any one of claims 1 to 9, wherein the protrusions are made of an elastomeric material.

11. The protrusions may be: - styrene ethylene butylene styrene (SEBS), silicone gels, in particular polydimethylsiloxane (PDMS), - polyurethane foam (PU), ethylene-vinyl acetate foam (EVA), - polyvinyl chloride (PVC), -EPDM rubber 11. The device according to any one of claims 1 to 10, made from a material selected from the group comprising:

12. 12. A device (30) according to any one of claims 1 to 11, comprising a base (20) designed to support at least the heel and the arch of the foot, and a soft layer (11) assembled on the rigid base and on which the protrusions (12) are formed.

13. The device (30) according to claim 12, wherein said base (20) is thermoformable at a temperature comprised between 60°C and 80°C.

14. The base comprises: - polycyclohexylene dimethylene terephthalate glycol (PCTG), polyethylene terephthalate glycol (PETG), - polycaprolactone (PCL), - Polylactide type polyester (PLA), ethylene vinyl acetate (EVA), - polyurethane (PU), polyethylene (PE), Polypropylene (PP), and - Thermoformable resin 14. The device of claim 13 made from a material included in the group comprising:

15. A method for manufacturing and shaping a device (30) according to any one of claims 13 and 14, comprising the steps of: - an initial step of manufacturing said device (30) in which said base (20) has a predetermined shape at its end; - thermoforming said base (20) in its arch area to adapt it to the shape of the user's foot, said thermoforming step comprising: - bringing the device to thermoforming temperature, for example by immersion in boiling water; - applying the device to the foot while the device is still hot and still within the thermoforming temperature range; and - exerting pressure under the device in the arch area to thermoform the device to the shape of the arch of the foot. a thermoforming step, A method comprising:

16. 15. A method for manufacturing a device according to any one of claims 1 to 14 by two-material injection moulding (M1, M2) in a mould (70, 90) comprising a first impression (71) designed to receive by injection moulding a material (M1) which will form the base (20) of the device, and a second impression (72) which will receive a material (M2) which will form the soft layer after injection moulding of the base.

17. 1. A method of non-therapeutic foot massage using a device (10, 11, 20, 30) designed to be positioned under all or part of the foot and at least under the arch of the foot, said device having a front surface designed to be in contact with the foot; the method comprising providing on the front surface of the device a plurality of solid protrusions (12) intended to contact the arch of the foot to exert a pressure capable of improving venous return, each protrusion having a base (120), a top (121), a height (h), and a shape determining the volume occupied by said protrusion, said protrusions being made of a soft, incompressible or moderately compressible material having a Poisson's coefficient greater than 0.30, and shaped and arranged such that flattening of said protrusions causes them to expand and fill all or part of the volume between each of said protrusions, significantly increasing the surface area of ​​the device in contact with the foot; and the method comprises: a first stage of blood evacuation by local pressure of each projection on the area of ​​the foot facing it; a second stage of blood evacuation after deformation of the projections under the influence of the pressure exerted by the foot; Including, the compressed protrusions together form an increased surface area over which venous return pressure is exerted on areas of the leg not desired during the first stage of blood evacuation. A method characterized by:

18. 18. The method of claim 17, comprising providing protrusions (12) in at least one region of the device, the protrusions (12) being shaped and arranged such that a 50% reduction in their height causes the protrusions to expand and fill the volume between each of the protrusions by at least 60%.

19. 19. A method according to any one of claims 17 and 18, comprising providing protrusions (12) in at least the arch region of the device, said protrusions (12) being shaped and arranged such that a 50% reduction in their height causes them to expand and fill the volume between each of said protrusions by at least 90%.

20. 20. The method according to any one of claims 17 to 19, wherein the protrusions are made of a material having a Shore A hardness comprised between 5 and 40, measured according to ISO 48-4.

21. A method according to any one of claims 17 to 20, wherein the projections are provided with increasing height as they approach the maximum arch region of the foot.

22. A method according to any one of claims 17 to 21, wherein the protrusion is provided with a constant or variable height (h) between its base and its apex comprised between 1.5 mm and 25 mm.

23. 23. The method according to any one of claims 17 to 22, wherein the device is designed to cover the heel and also the sole of the foot, and the method also comprises providing protrusions (13, 14) at least in the region of the forefoot corresponding to the metatarsophalangeal line and at least around the circumference of the heel.

24. 24. A method according to any one of claims 17 to 23, wherein the protrusions are given a substantially hemispherical shape and a height (h) comprised between 0.25 and 2.5 times the width (l) of the base (120) of the protrusion.

25. 25. A method according to any one of claims 17 to 24, wherein at least in the arch region of the device, two protrusions are separated by a spacing comprised between 0.1 and 0.5 times the width (l) of said protrusions or the average of the respective widths of said protrusions if said protrusions are not identical.

26. The method according to any one of claims 17 to 25, wherein the protrusions are realized in an elastomeric material.

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