FR2842710A1 - Footwear insole designed for postural stability has proximal support for metatarsus and tarsus with recess for calcaneum - Google Patents

Abstract

The insole, designed to be worn inside footwear to support the sole of the foot, is made from assembled thermoplastic components. It has an upper surface (2) that corresponds to the shape of the sole, covering a proximal support for the metatarsus (3), and a rear support for the tarsus (26). The proximal element has a recess (6) that corresponds to the head of the metatarses and forms a supporting arch (7) on a transverse line corresponding to the interdigital joints. The rear element has a recess (10) that corresponds to the position of the posterior tuberosity of the calcaneum and contains a foam shock absorber, and its forward end has outer (16) and inner (15) extensions to support the cuboid and scaphoid bones.

Description

The present invention relates to the technical field of soles or

supports

  for the plantar side of a human foot.

  In the above field, it is known to have, in shoes, soles or supports, said to be orthopedic, intended to correct disorders of stature or, again, to provide a feeling of comfort to their users. Thus, it is known to produce supports or soles by means of elements made of thermoplastic or thermoformable material, such as panels of ethyl vinyl acetate foam, crosslinked polyolefin foams, polyethylene foams or, sheets of resins, associated or not with reinforcements formed by grids of synthetic fabrics or not. These materials are then used to make supports which are thermoformed or molded on an impression of

  foot, preferably the imprint made on the foot of the user of the sole.

  If some of the supports thus produced allow, under certain conditions of use, to provide a feeling of comfort to their user, it has appeared to the applicant that, in most cases, the supports according to the prior art were not able to offer an element of postural stability sufficient to correct

  possible postural disorders or to ensure lasting comfort for the user.

  In order to remedy the drawbacks of the supports according to the prior art, the invention aims to propose a new support structure for the plantar surface of a foot, intended to be placed in a shoe and formed by the assembly

  elements made of thermoplastic materials.

  According to the invention, this plantar support is characterized in that it comprises: * a top element having the shape of the external contour of the foot, * and, under the top element: - a proximal metatarsal support element having , in the front part, a so-called head recess, which corresponds to the region of the head of the metatarsals and which defines a support arc situated at the level of a transverse line uniting the interdigital commissures of the foot, - a posterior support element of the tarsus and part of the metatarsus, presenting, in the rear part a recess, called calcaneal, at the level of the

  posterior tuberosity of the calcaneus.

  According to the invention, the rear support element can have different shapes. Thus, according to a characteristic of the invention, the front part of the posterior support element extends towards the external side of the plantar support to support the cubode as well as the base and part of the body of the fourth and fifth metatarsals. According to another characteristic of the invention, the front part of the posterior support element extends towards the internal side of the plantar support to support

  the scaphode as well as the base of the first and second metatarsals.

  Preferably, the plantar support also comprises at least one shock absorbing element arranged in the region of the tarsus to support the tuberosity

posterior of the calcaneus.

  According to a characteristic of the invention, the damping element and the calcaneus recess have a complementary shape. According to another characteristic of the invention, the damping element and the calcaneal recess each have a

circular shape.

  According to the invention, the proximal element can also have different shapes. Thus, according to a first embodiment, the proximal element has, at the front of its internal edge, a notch open at the level of the head recess and corresponding to the head of the first metatarsal and to the sesamode bone of the big toe. In the case of the implementation of such a configuration of the proximal element, the plantar support also comprises a sesamode element of

  support of the head of the first metatarsal and of the sesamoid bone of the big toe.

  According to a characteristic of the invention, the rear part of the element

  proximal has a pointed shape.

  Preferably but not strictly necessary, the posterior part of the internal side of the proximal element then has a concave shape, while the posterior part of the internal edge of the proximal element is concave towards the front and convex towards the rear. , so that the tip of the proximal element is oriented

  towards the internal side of the plantar support of the foot.

  According to another alternative embodiment of the invention, the proximal element is

  extends backwards and forms a support for the tarsus and metatarsus.

  In this configuration, the proximal element has, preferably but not strictly necessary, in the rear part, a recess, called calcaneal, located at the level of the posterior tuberosity of the calcaneus. The calcaneal recess of the proximal element is then found substantially in

  correspondence of the calcaneal recess of the posterior support element.

  According to another characteristic of the invention, the plantar support further comprises, under the top element, a median element for supporting the tarsus and the median region of the metatarsus, up to the head of the second and third metatarsals at the less. In certain configurations the middle support element can extend

  up to the head of the fourth metatarsal also.

  According to a characteristic of the invention, the median element has: * at the front of its external side, a notch corresponding at least to the body of the fifth metatarsal, * and, at the front of its internal side, a corresponding notch at least at

body of the first metatarsal.

  In certain variant embodiments, depending on the morphology of the user, the plantar support may also include a cubodian element

  located near the outer edge of the plantar support to support the cubode.

  Likewise, the plantar support can also include a scaphodian element situated near the internal edge of the plantar support to support the scaphod. Preferably, the plantar support according to the invention is thermoformed, so that its upper face has a shape complementary to that of the

  plantar face in front of it.

  Likewise, preferably, the underside of the support is shaped

  to define a substantially horizontal support plane.

  According to the invention, the various constituent elements of the support are made of thermoplastic materials of different hardnesses, so as to give the support flexibility and hardness which are different depending on the areas of the plantar surface of the foot concerned and which results from the superimposition of different elements

constitutive of the plantar support.

  According to a characteristic of the invention, the proximal element and the scaphoid and cuboid elements are produced in a polyacetal resin, while the other constituent elements of the support are produced in alveolar ethyl-venylacetate (EVA) plates of different densities . In order to obtain the best possible flexibility and hardness characteristics, according to a characteristic of the invention, the constituent elements of the support are arranged in a determined order from the rear face of the support, namely: * top element, * possibly damping element and sesamode element, * proximal element, * possibly scaphodian element and cubodian element, * possibly middle element, * possibly damping element,

  * and rear support element.

  The invention also relates to a method of manufacturing a plantar support according to the invention, comprising, in particular: * cutting the constituent elements of the plantar support from sheets of thermoplastic materials, * stacking the constituent elements of the support in accordance with their relative arrangement in the support,

  * thermoform the stack thus formed.

  According to another characteristic of the manufacturing process according to the invention, the plantar support is thermoformed on a molding of the imprint of the

plantar side of a foot.

  According to another characteristic of the invention, the support is, after thermoforming, machined, so that its underside defines a flat surface

support.

  Various other characteristics of the invention emerge from the description below, made with reference to the accompanying drawings which illustrate different forms

  not limiting the production of a plantar support according to the invention.

  Fig. i is a top view of a first embodiment of a plantar support according to the invention.

  Fig. 2 is a section along line 11-II of FIG. 1.

  Fig. 3 is a bottom view along line 111-111 of FIG. 2 of the support

  plantar as illustrated in figs. i and 2.

  The rig. 4 is a top view of a blank for a top element

  constituting the plantar support, as illustrated in rig. i.

  Fig. 5 is a top view of a proximal element constituting the support

plantar according to fig. i.

  Fig. 6 is a top view of a scapholid element constituting the support

plantar illustrated in fig. 1.

  The rig. 7 is a top view of a cubodian element of the plantar support of

fig. i.

  Fig. 8 is a top view of a damping element constituting the support

  plantar as illustrated in rig. i to 3.

  Fig. 9 is a top view of a central support element constituting the

  plantar support illustrated in figs. i to 3.

  Fig. 10 is a top view of a rear constituent support element

  plantar support, as illustrated in rig. i to 3.

  Fig. it is a top view of another embodiment of a support

plantar according to the invention.

  A plantar support according to the invention, illustrated in FIGS. i to 3 and designated as a whole by the reference 1, is constituted by the assembly of different elements intended to offer a support particularly adapted to the different zones of the plantar face of the foot i of the support user. The various constituent elements of the plantar support are then assembled in a stack, so as to form a complex which exhibits different mechanical behavior depending on the areas of the vote

plantar supported.

  The example of plantar support 1, illustrated in FIGS. 1 to 3, corresponds to a plantar support for a right foot, it being understood that the plantar supports for the foot

  right and left foot are noticeably enantiomorphic.

  Furthermore, the description of the various constituent elements of the support

  plantar 1 according to the invention will be carried out with reference to the locations of the different bones constituting the foot according to the terminology as defined by the work of Messrs. BOUCHER and CUILLERET having for title "Anatomy Descriptive and functional topography, 3D volume - the lower limb" ,

  SIMEP collection from Editions MASSON legal deposit March 2002.

  According to the present invention, the plantar support 1 comprises, first of all, a top element 2 having substantially the shape of the projection of the external contour of the right foot in a horizontal plane, as shown in FIG. 1. A draft of the top element, corresponding to the shape of this front element

  thermoforming and possibly machining, is illustrated in fig. 4.

  The top element is preferably made of a thermoplastic material such as, for example, a sheet of cellular material, such as ethyl vinyl acetate EVA. The top element is preferably chosen for

  have a thickness between 2mm and 3mm before thermoforming.

  The upper element can also be produced from a sheet of material sold under the name PXA 400. Insofar as the upper element can be found in direct contact with the foot, it can also be covered with leather. Just below the top element, the plantar support 2 comprises a proximal support element 3, more particularly illustrated in FIG. 5. The proximal support element is, according to the example illustrated, intended to provide a support or a

  support for the metatarsus, as well as for the tarsus.

  For this purpose, the proximal element has an external contour corresponding substantially to the shape of the sole of the foot and defined behind by a curved line with posterior convexity, at the front by a line parallel to the line corresponding to the digital plantar folds. but being in front of this line and, finally, on its internal side 4, by a line with internal concavity and, on its external side 5, by a

  line with very low internal concavity.

  In accordance with an essential characteristic of the invention, the proximal element 3 has, in the front part, a recess 6, called the head, which corresponds to the region of the head of the metatarsals and which defines, at the front of the proximal element 3, a support arch 7 located at a transverse line uniting the interdigital commissures of the foot. It should be noted that, according to the example illustrated, the head recess 6 corresponds to a cut made in the blank of material constituting the proximal element 3. In addition, the head recess 6 has substantially a shape of bean whose concavity is oriented towards the rear and whose outer end 8 is tightened, while

  1 0 that its inner end 9 is flared.

  Opposite the head recess 6, the proximal element has a recess, called calcaneal, located substantially at the level of the posterior tuberosity of the calcaneus. According to the example illustrated, the recess 10 has a substantially circular shape and corresponds to a cut made in the blank of material constituting

the proximal element 3.

  According to the invention, the proximal element 3 can be made of any suitable material and, preferably, chosen so that the proximal element constitutes a

  sort of elastic core or spring for the plantar support 1.

  To this end, the proximal element 3 is preferably made from an acetate resin plate such as, for example, a resin plate sold under the brand FLEX or Thermoflex. This plate can then include reinforcements of

textile fabrics.

  Depending on the applications and depending on the users of the plantar support, the proximal element is produced in a plate having, before thermoforming, a

  thickness, preferably but not necessarily, between 0.7 mm and 1.3 mm.

  The plantar support 1 then comprises a scaphodian element 15, illustrated individually in FIG. 6 and which is located, as shown in fig. 1, near the internal edge of the plantar support 1, to support the scaphode. According to the example illustrated, the scaphoid element 15 extends towards the posterior part of the plantar support 1 while avoiding the area of the calcaneal recess 10 of the element

proximal 3.

  The scaphodian element is preferably directly in contact with the proximal element 3 by being placed at the level of the lower face of the latter, opposite the top element 2. In addition, the element scaphodian 15 is, of

  preferably made of the same material as the proximal element 3.

  In addition to the scaphodian element 15, the plantar support 1 comprises, at the same level of stacking as the scaphodian element, a cuboid element 16 illustrated, individually, in FIG. 7. As shown more particularly in FIG. 1, the cubodian element 16 is located near the outer edge of the plantar support 1, so as to be able to support the cubode. Preferably, the cuboid element is made of the same material as the scaphoid element and

the proximal element.

  Thus the implementation in combination of the scaphoid element and the cubodian element makes it possible to constitute what could be called a postural stabilizer helping to offer good maintenance of the posture of a user of the support.

plantar according to the invention.

  The plantar support then comprises, still progressing from the upper face of the latter to its lower face, a damping element 17 which is arranged substantially at the calcaneal recess 10 of the proximal element. The damping element 17 preferably has a shape complementary to that of the calcaneal recess 10 and, according to the example illustrated, a circular shape, as shown in FIG. 8. The element 17 is intended to absorb the shocks of walking and is then preferably made of a thermoformable foam material, such as, for example, an ethyl vinyl acetate EVA foam. The damping element 17 is preferably made so as to present a

  thickness, preferably but not necessarily, between 3 and 8 mm.

  The next layer of the plantar support 1 is constituted by a median element for supporting the tarsus and the median region of the metatarsus, up to the head of the

  second and third metatarsals at least.

  Thus, as shown in fig. 9, the rear part of the median element 20 has a shape encompassing the entire tarsus, while the front part of its external side 21 has a notch 22 corresponding at least to the body of the fifth metatarsal, while the front part of its side internal 23 presents

  a notch 24 corresponding at least to the body of the first metatarsal.

  The median element is thus conformed to ensure optimal stimulation of the

  foot and user support vascular system.

  The middle element is preferably made of a thermoformable foam material, such as ethylene vinyl acetate EVA foam or polyethylene foam. Preferably but not strictly necessary, the median element is made of a sheet of polyethylene foam of a thickness included

between 2 mm and 4 mm.

  Finally, the plantar support includes a last layer on its face

  lower, constituted by a posterior element 26 for supporting the tarsus at least.

  According to the example illustrated in FIG. 10, the upper element 26 also ensures the

  support of the scaphoid as well as of the base of the first and second metatarsals.

  Thus, the anterior side 27 of the posterior element 26 has a shape convex towards the internal side of the posterior element 26 and which becomes concave towards the side

  outer 29 of the posterior element 26.

  In accordance with an essential characteristic of the invention, the rear element 26 has, in the rear part, a recess 30, called calcaneal, located at

  level of the posterior tuberosity of the calcaneus.

  Preferably, the recess 30 is constituted by a shape cutout

  circular, made in the blank of material constituting the posterior element 26.

  It should be noted that the calcaneal recess 30 is arranged so as to

  correspond to the calcaneal recess 17 of the proximal support element 3.

  Preferably but not strictly necessary, the posterior support element 26 is made of a relatively rigid thermoformable material such as, for example, a sheet of ethyl vinyl acetate foam having a density of between 150 kg / m3 and 400 kg / m3 and with a thickness between

2 and 5 mm.

  According to a preferred embodiment, the posterior support element 26 is made of polyethylene foam with a thickness of between 2 minutes and

  5 mm sold under the name PXA 400.

  It should be noted that, taking into account the implementation of the median element 20, the damping element is interposed between the top element 2 and said median element 20 which is, moreover, also interposed between the element

  shock absorber 17 and the calcaneal element 30 of the posterior support element 26.

  It should be noted that it could then be envisaged to fill the calcaneal recess 30 of the posterior support element 26 with a shock-absorbing element, not shown. The manufacturing of the plantar support 1 according to the invention is carried out as follows. After their cutting in plates of suitable material, the various constituent elements of the plantar support 1 are assembled flat, so as to form a complex which then undergoes thermoforming on, a foot molding. It is preferably used a molding of the foot of the end user of the plantar support. Preferably but not strictly necessary, the molding implemented is then produced from an imprint of a foot of the user carried out after a session of osteopathic manipulation of the latter. Thus, the molding used corresponds to the morphology of the foot when the user is in

an optimal postural state.

  In addition, the thermoforming of the plantar support is carried out to define, at the level of the central metatarsal zone of the top element, a convex conformation 35, as shown in FIG. 2. It should be noted that, according to the example illustrated, this convex conformation of the upper face of the plantar support 1

  corresponds a concave conformation of the underside of the plantar support 1.

  Of course, the convex conformation 35 is more or less accentuated depending on the case.

  Furthermore, it should be noted that the complexing of the various constituent elements of the plantar support can be carried out by gluing the latter to each other.

  others before thermoforming or simply result from thermoforming.

  After the thermoforming operation, the underside of the plantar support 1 is machined, so as to define a substantially horizontal support plane, more

  particularly illustrated in fig. 2.

  According to the invention, the shape of the various constituent elements of the plantar support can be modified according either to the morphology of the user, or to the conditions of use of the plantar support. Similarly, a plantar support il according to the invention does not necessarily include all of the elements

  components as described in relation to FIGS. 1 to 10.

  Thus, fig. 11 illustrates another embodiment of a plantar support 1a according to the invention which comprises the top element 2, the proximal support element 3 and the posterior support element 26. According to this embodiment, the part posterior of the proximal support element 3 and the anterior part of the posterior support element 26 have a

  complementary shape and overlap one another, like a puzzle.

  According to this example, the proximal support element 3 has a point-shaped rear part. Preferably, the rear part of the internal side of the proximal element 3 has a concave shape, while the rear part of the external edge 5 is concave towards the front and convex towards the rear, so that the

  tip of the proximal element is oriented towards the inside of the foot.

  Furthermore, the front part 34 of the rear support element 26

  has a concave shape towards the internal side, then convex towards the external side.

  In addition, the posterior support element 26 extends so as to provide support to the cubode, as well as to the base and to a part of the body of the fourth and fifth metatarsals. According to this embodiment, the proximal element 3 has, at the front of its internal edge 4, a notch 36 open at the level of the head recess 6 and

  corresponding to the head of the first metatarsal and the sesamode bone of the big toe.

  The plantar support then comprises a sesamode element 37 for supporting the head of the first metatarsal and the sesamode bone of the big toe. Preferably, this sesamode element 37 has a rigidity lower than that of the material

  constituting the proximal element 3 and the posterior support element 26.

  It should, moreover, be noted that such a notch associated with a sesamode element could also be implemented with a proximal element as described in relation to the plantar support 1 as described in relation to FIGS. 1 to 10. Finally, the plantar support 1a, as illustrated in FIG. 11, also implements a damping element 17, disposed in the calcaneal recess of the element

support posterior 26.

  Of course, various other modifications can be made to the plantar support 1, without departing from the scope of the present invention, thus other combinations of the constituent elements of the plantar support could be envisaged that

those described above.

Claims (19)

  1 - Plantar support for the underside of a foot, formed by the assembly of elements made of thermoplastic materials and intended to be placed in a shoe, characterized in that it comprises: has a top element (2) having the shape of the external contour of the foot, w and, under the top element: - a proximal element (3) for supporting the metatarsus having, in the front part, a recess, called the head, (6) which corresponds to the region of the head of the metatarsals and which defines a support arc (7) situated at the level of a transverse line uniting the interdigital commissures of the foot, - a posterior element (26) for supporting the tarsus and a metatarsal part, presenting, in the rear part a recess, said calcaneal, (30) at the level   posterior calcaneus tuberosity.   2 - Plantar support according to claim 1, characterized in that the front part of the posterior support element (26) extends towards the external side of the plantar support to support the cubode as well as the base and part of the body of the   fourth and fifth metatarsals.   3 - Plantar support according to claim 1, characterized in that the front part of the posterior support element (26) extends towards the internal side of the plantar support to support the scaphode as well as the base of the first and second metatarsals. 4 - Plantar support according to claim 1 to 3, characterized in that the part   posterior of the proximal element (3) has a pointed shape.   - Plantar support according to claim 4, characterized in that: * the rear part of the internal side (4) of the proximal element (3) has a concave shape, w and the rear part of the external edge (5) of the proximal element (3) is concave towards the front and convex towards the rear, so that the point of   the proximal element is oriented towards the internal side of the plantar support.   6 - Plantar support according to one of claims 1 to 3, characterized in that   the proximal element (3) extends rearward and forms a support for the tarsus and the metatarsus.   7 - Plantar support according to claim 6, characterized in that the proximal element (3) has, in the rear part, a recess, called calcaneal, (10) located at   level of the posterior tuberosity of the calcaneus.   8 - Plantar support according to one of claims 1 to 7, characterized in that it   further comprises, under the top element (2), a median element (20) for supporting the tarsus and the median region of the metatarsus up to the head of the second and at least third metatarsals.   9 - Plantar support according to claim 8, characterized in that the median element (20) has: m at the front of its external side (21), a notch (22) corresponding at least to the body of the fifth metatarsal, a and, at the front of its internal side (23), a notch (24) corresponding to the   less to the body of the first metatarsal.   - Plantar support according to one of claims 1 to 9, characterized in that it   includes a cuboid element (16) located near the outer edge of the support   plantar to support the cubode.   11 - Plantar support according to one of claims 1 to 10, characterized in   that it includes a scaphodian element (15) located near the internal edge of the   plantar support to support the scaphode.   12 - Plantar support according to one of claims 1 to 11, characterized in that   that it comprises at least one damping element (17) arranged in the region of the tarsus   to support the posterior tuberosity of the calcaneus.   13 - Plantar support according to claim 12, characterized in that the damping element (17) and the calcaneal recess (30) have a shape complementary.   14 - Plantar support according to claim 13, characterized in that the damping element (17) and the calcaneal recess (30) each have a shape substantially circular.   - Plantar support according to one of claims 12 to 14, characterized in   that a component of the plantar support is interposed between the damping element (17) and the calcaneal recess (30) of the posterior support element (26).   16 - Plantar support according to one of claims 1 to 15, characterized in that   the proximal element (3) has, at the front of its internal edge, a notch (36) open at the level of the head recess (6) and corresponding to the head of the first   metatarsal and sesamode bone of the big toe.   17 - Plantar support according to claim 16, characterized in that it comprises a sesamode element (37) for supporting the head of the first metatarsal and the bone sesamode of the big toe.   18 - Plantar support according to one of claims 1 to 17, characterized in   that it is thermoformed, so that its upper face has a shape   complementary to that of the plantar surface which should bear against it.   19 - Plantar support according to one of claims 1 to 18, characterized in that   its underside defines a support plane.   - Plantar support according to one of claims 1 to 19, characterized in that   the various constituent elements of the support are made of materials   thermoplastics of different hardness.   21 - Plantar support according to one of claims 1 to 20, characterized:   * in that the proximal element, the scaphodian and cubodian elements are made in a polyacetal resin, * and in that the other constituent elements of the support are made in   Alveolar ethyl vinyl acetate (EVA) plates.   22 - Plantar support according to one of claims 1 to 21, characterized in that   the constituent elements of the plantar support are arranged in the following order from the upper face of the support: * top element (2), * optionally damping element (17) and sesamode element (36), * proximal element (3) , * possibly scaphodian elements (15) and cubodian element (16), * possibly median element (20), * possibly damping element (17),   * and rear support element (26).   23 - Method of manufacturing a plantar support according to one of claims 1   to 22, characterized in that it consists, in particular, in: * cutting the constituent elements of the plantar support in plates of thermoplastic materials, * stacking the constituent elements of the support in accordance with the relative arrangement in the support, * thermoforming the stack thus formed. 24 - Manufacturing method according to claim 23, characterized in that it consists in thermoforming the support on a molding of the imprint of the plantar face of a foot.   - Manufacturing method according to claim 24 characterized in that it consists in implementing a molding produced from an imprint, of a foot of the support user, carried out after a session of osteopathic manipulation of this user.   26 - Manufacturing method according to one of claims 23 to 25, characterized in   what it consists of, after thermoforming, machining the underside of the support   1 5 plantar so that it defines a support plane.