FR3160858A1 - Reinforcement element for sports shoes - Google Patents

Abstract

Reinforcing element for a sports shoe Sole (2) for a sports shoe (1) comprising a reinforcing element (11), the reinforcing element being intended to extend under the plantar fascia (44), the reinforcing element comprising a rear portion (21), a front portion (22), and a central hinge (23) connecting the front portion to the rear portion, the front portion being less rigid than the rear portion, the rear portion being intended to extend in front of a posterior support point (41) of the foot, the front portion comprising at least one longitudinal branch (24, 25), the at least one longitudinal branch being intended to extend between an antero-internal support point (42) and an antero-external support point (43) of the foot. Figure for abstract: Figure 10

Description

Reinforcement element for sports shoes Technical field of the invention

The invention relates to a reinforcing element for a sole of a sports shoe. The invention also relates to a sports shoe, in particular a sports shoe suitable for running on uneven terrain, comprising such a reinforcing element.

State of the prior art

Trail running, more commonly known as "trail" or "trail running," is a sport that involves running or walking on a course in a natural environment. Participants are therefore required to run or walk on uneven and/or slippery trails and/or uphill or downhill. Trails can be, for example, mountain paths strewn with stones, roots, snow, or even sand. Trail running can even be practiced off-trail. Practicing this sport requires not only the endurance skills specific to running, but also great agility to efficiently cover these uneven terrains without injury.

Running on uneven terrain therefore requires the use of specific shoes that not only allow you to run but also have the following properties:
- These shoes must be particularly resistant because they are regularly subjected to shocks and/or friction.
- These shoes must absorb shocks, sometimes very significant, especially during descents.
- These shoes must be very stable to limit the risk of twisting the ankle when running on sloping terrain, as a sprained ankle is a very common injury when running on uneven terrain.
- These shoes must also be very light to minimize effort, especially when climbing.
- Finally, these shoes must transmit impulses efficiently to allow fast running when the terrain allows it.

The state-of-the-art shoes for running on uneven terrain do not meet all of these properties. Therefore, improvements to existing sports shoes are desirable.

Presentation of the invention

The aim of the invention is to provide a shoe for running on uneven terrain that is durable, effectively absorbs shocks, stable, lightweight and effectively transmits the impulses of its users.

The invention relates to a sole for a sports shoe comprising a reinforcing element, the reinforcing element being intended to extend under the plantar fascia, the reinforcing element comprising a rear part, a front part, and a central hinge connecting the front part to the rear part, the front part being less rigid than the rear part, the rear part being intended to extend in front of a posterior support point of the foot, the front part comprising at least one longitudinal branch, the at least one longitudinal branch being intended to extend between an antero-internal support point and an antero-external support point of the foot.

The at least one longitudinal branch may comprise a first longitudinal branch and a second longitudinal branch extending parallel to the first longitudinal branch.

The first longitudinal branch may comprise a substantially constant width and thickness, and/or the second longitudinal branch may comprise a substantially constant width and thickness.

The first longitudinal branch may comprise a substantially straight inner lateral edge and a substantially straight outer lateral edge, and/or the second longitudinal branch may comprise a substantially straight inner lateral edge and a substantially straight outer lateral edge.

The rear portion of the reinforcing member may be intended to extend under a navicular bone, under a cuboid bone, under cuneiform bones, and under a rear portion of the five metatarsals of a foot, and the at least one longitudinal branch may be intended to extend under a front portion of the second metatarsal and/or under a front portion of the third metatarsal.

The rear portion of the reinforcing member may include a set of closed-contour openings.

The rear portion of the reinforcing element may comprise a set of stiffening ribs, the stiffening ribs extending projectingly, in particular downwardly, relative to a plane in which the rear portion extends.

Said stiffening ribs may be arranged on the closed contour of said openings.

The rear portion of the reinforcing member may include an upwardly extending inner lateral rim for extending along an inner lateral edge of the plantar fascia, and/or the rear portion of the reinforcing member may include an upwardly extending outer lateral rim for extending along an outer lateral edge of the plantar fascia.

The rear portion of the reinforcing member may include a rear indentation configured to move the rear fulcrum away from a rear edge of the reinforcing member by at least one centimeter.

The central hinge may form a narrowest area of the reinforcing element along a transverse axis.

The reinforcing element can be a monolithic element made of plastic and obtained by molding.

The sole may include an upper portion having an upper surface for receiving a lower surface of a foot, the upper portion including an upper cushioning layer, the upper portion extending above the reinforcing member.

The sole may include a lower portion having a lower surface for contacting the ground, the lower portion including a lower cushioning layer, the lower portion extending above the reinforcing element.

The reinforcing element may comprise an exposed internal face on an internal side of the sole and/or an exposed external face on an external side of the sole.

The invention also relates to a sports shoe, in particular a sports shoe suitable for running, preferably on uneven terrain, comprising a sole as defined above.

Presentation of figures

These objects, characteristics and advantages of the present invention will be explained in detail in the following description of a particular embodiment made without limitation in relation to the attached figures among which:

There FIG. 1 is a top and exploded perspective view of a sports shoe according to one embodiment of the invention.

There FIG. 2 is a perspective view from below and exploded of the sports shoe of the FIG. 1 .

There FIG. 3 is a side view of a sole of the sports shoe.

There FIG. 4 is a top view of a reinforcing element of the sole of the FIG. 3 .

There FIG. 5 is a profile view of the reinforcement element.

There FIG. 6 is a perspective view from below of the reinforcing element.

There FIG. 7 is a top perspective view of the reinforcing element.

There FIG. 8 is a schematic side view of the anatomy of a foot of a sports shoe user.

There FIG. 9 is a schematic top view of the anatomy of the foot of the sports shoe user.

There FIG. 10 is the schematic top view of the anatomy of the foot of the FIG. 9 on which a top view of the sole of the FIG. 3 .

Detailed description

Figures 1 and 2 illustrate, by exploded views, a sports shoe 1 suitable for running, in particular on uneven terrain, that is to say suitable for trail running. The sports shoe 1 mainly comprises a sole 2 and an upper 3. The sole 2 designates the part of the shoe 1 which extends between the lower surface of a foot and the ground on which the shoe rests. The upper 3 designates the part of the shoe 1 which extends around and above the foot. The upper 3 is shown schematically in Figures 1 and 2. The upper 3 notably comprises an upper opening for inserting the foot into the shoe 1, a tongue and tightening means, for example laces, for tightening the upper around the user's foot. The upper 3 may for example be made of fabric. It may comprise one or more pieces of fabric assembled together, and may optionally be provided with reinforcing elements. The upper 3 is fixed, for example sewn or glued, to the sole 2.

The shoe 1 illustrated in the figures is a shoe for a right foot. The invention can of course be adapted for a left shoe and for any shoe size. It is assumed that the shoe rests on horizontal ground via its sole 2. The longitudinal axis X designates the horizontal axis oriented from the back to the front of the shoe, that is to say from the heel to the toes. The transverse axis Y designates the horizontal axis, perpendicular to the longitudinal axis X, oriented from left to right, left and right being defined according to the point of view of the user of the shoe 1 when looking in front of him. The vertical axis Z designates the axis perpendicular to the longitudinal axis X and to the transverse axis Y. The vertical axis Z is oriented from bottom to top. In the remainder of the description, the terms "lower" and "upper" characterize an arrangement along the vertical axis Z. The terms "inner" and "outer" characterize an arrangement along the transverse axis Y: the inner side of the shoe designates the side of the shoe facing the user's second foot. The outer side of the shoe designates the side of the shoe opposite the inner side. In the case of a right shoe, the inner side therefore relates to the left side of the shoe and the outer side relates to the right side of the shoe.

As can be seen on the FIG. 3 , the sole 2 comprises, in a longitudinal and vertical plane, a lower surface of convex shape to promote good rolling of the foot when running. In particular, a rear part 4 and a front part 5 of the sole each comprise a lower surface in the shape of an arc of a circle, a center of the arc of a circle being positioned above the ground. The rear part 4 and the front part 5 are connected by an intermediate part 6 whose lower surface is substantially horizontal. The thickness of the sole 2 along the vertical axis Z may be roughly decreasing when traveling along the sole 2 from the back to the front.

With reference to Figures 1 and 2, the sole 2 comprises a plurality of superimposed layers. The sole 2 comprises in particular an upper part 7 provided with an upper surface 8 in contact with the upper and/or directly with the lower surface of a foot, a lower part 9 provided with a lower surface 10 in contact with the ground, and a reinforcing element 11 interposed between the upper part 7 and the lower part 9. The lower part 9 comprises a lower shock-absorbing layer 12 and a wear layer 13 arranged under the lower shock-absorbing layer 12.

The wear layer 13 advantageously comprises a set of gripping studs 14 allowing the sole to adhere to uneven terrain such as rocks, sand or even snow. The wear layer 13 may for example be made of rubber, or even polyurethane (PU). The wear layer 13 also comprises a stone guard 15 arranged at its front end. The stone guard 15 is a substantially vertical part of the outsole, protecting the toes against frontal impacts.

The upper portion 7 comprises an upper cushioning layer 16. The lower cushioning layer 12 and the upper cushioning layer 16 may be made of a cushioning synthetic polymer, such as a foam. For example, the lower cushioning layer 12 and the upper cushioning layer 16 may be made of ethylene vinyl acetate (EVA) and/or polyurethane (PU). The upper cushioning layer 16 may optionally also comprise a sockliner intended to come into direct contact with a foot (or indeed with a sock worn around a foot).

The reinforcing element 11 is embedded in the sole 2, and is therefore mostly invisible from the outside of the shoe 1. The inner and outer lateral edges of the reinforcing element may nevertheless be visible respectively on the inner and outer sides of the sole. The reinforcing element may therefore comprise outer faces 81, 82 visible on the inner and outer sides of the sole 2. The outer face 82 is in particular clearly visible on the FIG. 3 . Advantageously, the reinforcing element 11 remains covered from above by the upper part 7. Thus, the reinforcing element does not come into direct contact with the user's foot, which allows the sports shoe to remain comfortable. Similarly, the reinforcing element 11 is covered from below by the lower part 9. Thus, the reinforcing element does not come into direct contact with the ground. This avoids damaging the reinforcing element by contact with uneven ground, for example with stones. According to an alternative embodiment of the invention, the reinforcing element 11 could be completely embedded in the sole 2, without a visible face from the outside of the sole 2, or else comprise a visible face on only one of the two lateral sides of the sole.

The reinforcing element 11 is illustrated in isolation in Figures 4 to 7. The reinforcing element 11 is preferably made of a plastic material, possibly reinforced with fibers. For example, the reinforcing element 11 may comprise polyamide (PA), acrylonitrile butadiene styrene (ABS), or any other plastic material with similar mechanical properties. The material may also be reinforced with different types of fillers such as glass or carbon fibers. The reinforcing element 11 may be a monolithic element, for example obtained by molding, in particular by injecting plastic into an injection mold.

The reinforcing element 11 is a component of the sole that provides it with rigidity, stability and dynamism. The reinforcing element has a specific shape and dimensions that enable it to achieve these objectives without adding weight to the sole 2, and without penalizing the sole's ability to absorb shocks, in particular vertical shocks that occur when the forefoot or heel come into contact with the ground.

In relation to Figures 4 to 7, it can be seen that the reinforcing element 11 comprises a rear part 21, a front part 22 and a central hinge 23 connecting the front part 22 to the rear part 21. The rear part 21 comprises a positioning, a shape and a rigidity adapted to obtain a particularly stable support on the ground. The front part 22 comprises a positioning, a shape and a rigidity giving the sole a certain elasticity, thus allowing a particularly effective transmission of the supports of the user 1.

The rear portion 21 and the front portion 22 respectively comprise a length L1 and a length L2 along the longitudinal axis X. The total length L3 of the reinforcing element 11 along the longitudinal axis X is equal to the sum of the lengths L1 and L2. Preferably, the length L2 is within the interval defined by 70% of the length L1 and 100% of the length L1. The total length L3 of the reinforcing element 11 may be between 50% and 80%, preferably between 60% and 70%, of the total length L4 of the sole 2 along the longitudinal axis X.

The central hinge 23 can be positioned substantially in the center of the reinforcing element 11 or slightly towards the front of the reinforcing element along the longitudinal axis X. The central hinge 23 can be positioned at a distance d1 from the rear edge of the sole of between 50% and 70% of the total length L4 of the sole 2.

The rear part 21 comprises a width L5 along the transverse axis Y strictly greater than the width L6 of the front part 22 along this same axis. In particular, the width L5 may be at least equal to 150% of the width L6, preferably at least equal to 200% of the width L6. The width L5 of the rear part 21 may be substantially equal to the width L9 of the sole 2 along the transverse axis Y, the width L9 being considered at mid-length of the sole along the longitudinal axis X.

To better understand the functioning of the reinforcing element 11, we also recall certain characteristics of the anatomy of the foot in relation to figures 8 and 9. The structure of a foot comprises different bones including the calcaneus 31, the talus 32, the navicular bone 33, the cuboid bone 34, the cuneiform bones 35.1, 35.2, 35.3, five metatarsals 36.1, 36.2, 36.3, 36.4 and 36.5 and phalanges 37. The first metatarsal 36.1 is positioned on the side of the biggest toe and the fifth metatarsal 36.5 is positioned on the side of the smallest toe. The phalanges 37 are positioned in the extension of the metatarsals. The tibia 38 and fibula 39 extend upward from the talus 32. When running, the phalanges articulate relative to the metatarsals.

The foot naturally comprises three support points 41, 42, 43 on the ground thanks to which a person can remain stable when supporting himself on a single foot. A first support point 41, or posterior support 41, is positioned directly above a lower end of the calcaneus bone. The first support point 41 thus corresponds to the area of the heel which first comes into contact with the ground when walking or running. A second support point 42, or antero-internal support point 42, is positioned directly above a head of the first metatarsal 36.1, that is to say directly above a front protuberance of the first metatarsal 36.1. A third support point 43, or antero-external support point of the foot 43, is positioned directly above the head of the fifth metatarsal 36.5. The three support points 41, 42 and 43 are not aligned and are therefore positioned at the three vertices of a triangle.

The foot also includes a plantar fascia 44, also known as the plantar fascia. The plantar fascia 44 is a thick band of connective tissue located on the underside of the foot. It extends from the calcaneus 31 to the heads of metatarsals 36.1, 36.2, 36.3, 36.4, and 36.5, forming the plantar arch or vault. It comprises a set of fibers running longitudinally, represented by dotted lines on the FIG. 9 . The plantar fascia 44 forms a relatively soft area under the foot, unlike the three support points 41, 42 and 43 which are firmer areas. The plantar fascia 44 plays a crucial role in maintaining the arch of the foot and in transmitting force during running.

On the FIG. 10 , we have superimposed the anatomy of the foot represented on the FIG. 9 with the reinforcing element 11 to clearly visualize the position of the latter. The reinforcing element 11 is intended to extend under the plantar fascia 44, and at a distance from the three support points 41, 42, 43. The reinforcing element 11 therefore does not extend under any of the three support points 41, 42 and 43. The three support points 41, 42 and 43 of the foot are thus freed from the reinforcing element 11. The three support points 41, 42 and 43 are thus effectively cushioned by the cushioning layers 12 and 16 of the sole, without the reinforcing element 11 disturbing the cushioning effect of these layers. Conversely, the soft tissues of the foot are effectively supported and protected by the reinforcing element 11.

The rear part 21 of the reinforcing element extends in particular in the intermediate part 6 of the sole 2. The rear part 21 extends in particular under the navicular bone 33, under the cuboid bone 34, under the cuneiform bones 35.1, 35.2, 35.3, and under a rear part of the five metatarsals 36.1, 36.2, 36.3, 36.4 and 36.5. The rear portion 21 extends mainly in front of the calcaneus 31. The reinforcing element therefore does not extend under the calcaneus 31 or only under a front end of the calcaneus 31. In particular, the rearmost point or edge of the reinforcing element 11 is positioned in front of the first support point 41. Advantageously, the rearmost point or edge of the reinforcing element 11 is distant from the first support point 41 by at least approximately one centimeter, or even at least 15 millimeters, or even at least two centimeters.

The front portion 22 of the reinforcing element extends longitudinally between the two support points 42 and 43. In particular, the front portion 22 extends mainly under a front portion of the second metatarsal 36.2 and/or under a front portion of the third metatarsal 36.3.

The central hinge 23 of the reinforcing element makes it possible to decouple the front part 22 from the rear part 21. The central hinge 23 can in particular be formed by a narrower portion of the reinforcing element 11 along the transverse axis Y. As can be seen in the FIG. 10 , the central hinge 23 is positioned inside the triangle formed by the three support points 41, 42 and 43 of the foot.

The front portion 22 of the reinforcing element is less rigid than the rear portion 21. Due to this difference in rigidity, the reinforcing element 11 flexes elastically exclusively or almost exclusively at its front portion 22 when the foot exerts a vertical bending force on the reinforcing element 11, during running. The rear portion 21 remains generally undeformed when such a bending force is exerted. On the FIG. 5 , the shape of the reinforcing element 11 when it is subjected to a bending force representative of the bending force exerted by the foot when running is represented by dotted lines T1 and T2. Thanks to the difference in rigidity between the rear part 21 and the front part 22, the rear part 21 remains undeformed, which provides stability to the sports shoe, while the front part provides elasticity and allows efficient propulsion of the user.

As is clearly visible on the FIG. 4 , the front part 22 comprises two longitudinal branches 24, 25 extending parallel to each other. The front part 22 thus comprises substantially the shape of a U or a tuning fork. The two longitudinal branches 24 and 25 meet at the hinge 23. A first longitudinal branch 24 extends under an internal half of the plantar fascia 44, and in particular under the second metatarsal 36.2. A second longitudinal branch 25 extends under an external half of the plantar fascia 44, and in particular under the third metatarsal 36.3. Each of the two longitudinal branches 24 and 25 can flex independently of the other branch. The use of at least two branches thus allows the sole to better conform to the shapes of uneven terrain. In particular, the presence of two branches improves the lateral stability and lateral dynamism of the shoe 1 during the support or impulse phases on the ground. If the foot rests on the ground more on its internal half, the first longitudinal branch 24 will tend to deform more than the second longitudinal branch 25. The first longitudinal branch 24 will provide dynamism to the support of the foot, while the second longitudinal branch 25 will provide stability. Conversely, if the foot rests on the ground more on its external half, the second longitudinal branch 25 will tend to deform more than the first longitudinal branch 24. The second longitudinal branch 24 will provide dynamism to the support of the foot, while the first longitudinal branch 24 will provide stability. The use of at least two branches is therefore particularly useful for running on uneven terrain.

The first longitudinal branch 24 comprises a substantially rectilinear inner lateral edge 26 and a substantially rectilinear outer lateral edge 27. Similarly, the second longitudinal branch 25 comprises a substantially rectilinear inner lateral edge 28 and a substantially rectilinear outer lateral edge 29. The four edges 26, 27, 28, 29 are substantially parallel to the longitudinal axis X or possibly slightly inclined towards the inner edge of the foot to take into account the natural shape of the foot. The width L7, L8 of the two longitudinal branches 24 and 25 is therefore substantially constant along these longitudinal branches. The width L7 is substantially equal to the width L8. The distance d2 separating the two longitudinal branches 24 and 25 is also substantially constant along these longitudinal branches. The thickness e1 of the two longitudinal branches 24 and 25 along the vertical axis Z may be uniform, for example of the order of one or two millimeters.

According to an alternative embodiment, the front part 22 could comprise a different number of longitudinal branches, for example a single longitudinal branch. Conversely, the front part could comprise at least three longitudinal branches. In all cases, the longitudinal branch(es) extend at a distance from the support points 41, 42 and 43.

The rear portion 21 of the reinforcing element extends generally in a horizontal plane. The rear portion 21 may be flat or slightly curved upwards. The rear portion 21 comprises the shape of an openwork plate. The rear portion 21 thus comprises a set of openings 51, 52, 53, 54, 55, 56, 57 with a closed contour. By “opening with a closed contour” is meant a hole passing through the rear portion 21, the contour of which forms a line closed on itself. The integration of contoured openings makes it possible to lighten the rear portion 21 without significantly penalizing its rigidity. The rear portion also comprises a set of substantially rectilinear arms 61, 62, 63, 64, delimiting the openings 51, 52, 53, 54, 55, 56, 57. The arms 61, 62, 63, 64 are connected to each other in a network pattern. A first arm 61 extends from the hinge 23 towards the rear and towards an inner side of the reinforcing element. An angle formed between the first arm 61 and the longitudinal axis X may be, for example, between 30° and 45° inclusive. A second arm 62 extends from the hinge 23 towards the rear end of the inner side of the reinforcing element. An angle formed between the second arm 62 and the longitudinal axis X may be, for example, between 10° and 30° inclusive. A third arm 63 extends from the hinge 23 towards the rear end of the outer side of the reinforcing element. An angle formed between the third arm 63 and the longitudinal axis X may be, for example, between 10° and 30° inclusive. A fourth arm 64 extends from the hinge 23 towards the rear and towards an outer side of the reinforcing element. An angle formed between the fourth arm 64 and the longitudinal axis X may be, for example, between 30° and 45° inclusive. The four arms 61, 62, 63, 64 thus form four spokes which extend from the hinge 23 towards the rear and in different directions.

To stiffen the rear portion 21, the latter also comprises a set of stiffening ribs 71, 72, 73. The stiffening ribs 71, 72, 73 extend projecting from a plane in which the rear portion extends. Advantageously, the stiffening ribs 71, 72, 73 extend downwards from the plane in which the rear portion 21 extends, for example by a few millimeters, for example between one and three millimeters. Thus, the rear part 21 retains a generally flat upper surface and the formation of pressure points under the plantar fascia 44 is avoided. In particular, the stiffening ribs 71, 72, 73 are formed respectively on the contour of the openings 51, 54 and 55. Such positioning is particularly effective for stiffening the rear part of the reinforcing element while limiting its volume and weight.

As can be seen on the FIG. 1 , the upper surface of the lower damping layer 12 comprises an imprint 74 matching the shape of the reinforcing element 11. In particular, the imprint 74 may in particular comprise recesses of a shape complementary to the stiffening ribs 71, 72, 73 and/or protrusions of a shape complementary to the openings 51, 52, 53, 54, 55, 56, 57. Similarly, as can be seen in the FIG. 2 , the lower surface of the upper damping layer 16 comprises an imprint 75 matching the shape of the reinforcing element 11. The imprint 75 may also comprise protrusions of a shape complementary to the openings 51, 52, 53, 54, 55, 56, 57. Thus, the integration of the reinforcing element 11 between the lower damping layer 12 and the upper damping layer 16 does not generate any tension in the material constituting these damping layers. The damping layers 12 and 16 thus retain all their damping power to absorb shocks linked to sports practice. In addition, the damping layers 12 and 16 can also be in direct contact with each other outside the reinforcing element 11, in particular under each of the three support points 41, 42 and 43. This prevents the formation of air pockets between the damping layers 12 and 16.

The damping layers 12 and 16 provided with their imprints 74 and 75 can, for example, be obtained by molding. The two damping layers 12 and 16 can be glued against each other, thus trapping the reinforcing element between the two damping layers. In addition, the reinforcing element 11 could possibly be glued to the lower damping layer 12 and/or to the upper damping layer 16. According to another manufacturing technique, the reinforcing element 11 could be integrated into a mold for manufacturing the lower damping layer 12 or the upper damping layer 16. The material forming the damping layer 12 or 16 would then be overmolded onto the reinforcing element 11.

The rear portion 21 of the reinforcing element also comprises an internal lateral edge 65 and an external lateral edge 66. The internal lateral edge 65 and the external lateral edge 66 are positioned respectively along the internal side and along the external side of the sole. The internal lateral edge 65 and the external lateral edge 66 therefore extend respectively along an internal lateral edge and along an external lateral edge of the plantar fascia 44. In other words, the internal lateral edge 65 and the external lateral edge 66 frame the plantar fascia 44. The lateral edges 65 and 66 make it possible on the one hand to increase the rigidity of the reinforcing element 11, but also contribute to the support and overall stability of the foot. The side edges 65 and 66 therefore reduce the risk of twisting the ankle when running on uneven terrain.

As mentioned previously, the internal lateral edge 65 comprises an internal face 81 visible from the outside of the sole. Similarly, the external lateral edge 66 comprises an external face 82 visible from the outside of the sole. It is therefore understood that the rear part 21 of the reinforcing element extends over the entire width of the sole 2.

The inner side flange 65 and the outer side flange 66 both extend upwardly from the plane in which the rear portion 21 extends. These flanges may, for example, project upwardly by a few millimeters.

The inner side flange 65 may connect a rear end of the first arm 61 to a rear end of the second arm 62. Secondary arms 67 may also connect the second arm 62 to the inner side flange 65. The outer side flange 66 may connect a rear end of the third arm 63 to a rear end of the fourth arm 64. Secondary arms 68 may also connect the third arm 63 to the outer side flange 66.

The rear portion 21 of the reinforcing element also comprises a rear notch 58 configured to completely distance the reinforcing element from the rear support point 41 of the foot. The rear notch 58 makes it possible in particular to distance the rear support point 41 from the rear edge of the reinforcing element by at least one centimeter. This makes it possible to maintain a very effective cushioning effect of the cushioning layers 12 and 16.

The rear notch 58 is an open-contour opening. The rear notch 58 may comprise an arcuate shape or a U-shape extending from a rear end of the inner lateral flange 65 to a rear end of the outer lateral flange 66. The center of said arcuate shape is positioned at the rear of the reinforcing element, substantially at the level of the rear support point 41. The rear ends of the inner lateral flange 65 and the outer lateral flange 66 respectively form the rearmost points 76 and 77 of the reinforcing element 11. The edge of the rear notch 58 may be formed by a rear portion of the second arm 62, a rear portion of the third arm 63, and a fifth arm 69 connecting the second arm 62 to the third arm 63. The distance L10 (identified on the FIG. 2 ) defined between the rear edge of the fifth arm 69 and the rear edge of the sole 2 along the longitudinal axis X may be at least equal to 20% of the total length L4 of the sole along this same axis, preferably at least 30%, or even at least 40% of the total length L4.

Finally, thanks to the invention, we have a shoe suitable for running on uneven terrain which effectively absorbs shocks, particularly under the three natural support points of the foot, and which is particularly stable, which limits the risk of the user twisting their ankle.

Claims (15)

Sole (2) for a sports shoe (1) comprising a reinforcing element (11), the reinforcing element being intended to extend under the plantar fascia (44), the reinforcing element comprising a rear portion (21), a front portion (22), and a central hinge (23) connecting the front portion to the rear portion, the front portion being less rigid than the rear portion, the rear portion being intended to extend in front of a posterior support point (41) of the foot, the front portion comprising at least one longitudinal branch (24, 25), the at least one longitudinal branch being intended to extend between an antero-internal support point (42) and an antero-external support point (43) of the foot.
Sole (2) according to the preceding claim, characterized in that the at least one longitudinal branch comprises a first longitudinal branch (24) and a second longitudinal branch (25) extending parallel to the first longitudinal branch.
Sole (2) according to the preceding claim, characterized in that the first longitudinal branch (24) comprises a substantially constant width and thickness, and/or in that the second longitudinal branch (25) comprises a substantially constant width and thickness.
Sole (2) according to one of claims 2 or 3, characterized in that the first longitudinal branch (24) comprises a substantially rectilinear internal lateral edge (26) and a substantially rectilinear external lateral edge (27), and/or in that the second longitudinal branch (25) comprises a substantially rectilinear internal lateral edge (28) and a substantially rectilinear external lateral edge (29).
Sole (2) according to one of the preceding claims, characterized in that the rear portion (21) of the reinforcing element (11) is intended to extend under a navicular bone (33), under a cuboid bone (34), under cuneiform bones (35.1, 35.2, 35.3), and under a rear portion of the five metatarsals (36.1, 36.2, 36.3, 36.4, 36.5) of a foot, and in that the at least one longitudinal branch (24, 25) is intended to extend under a front portion of the second metatarsal (36.2) and/or under a front portion of the third metatarsal (36.3).
Sole (2) according to one of the preceding claims, characterized in that the rear part (21) of the reinforcing element (11) comprises a set of openings (51, 52, 53, 54, 55, 56, 57) with a closed contour.
Sole (2) according to one of the preceding claims, characterized in that the rear part (21) of the reinforcing element (11) comprises a set of stiffening ribs (71, 72, 73), the stiffening ribs extending in projection, in particular downwards, relative to a plane in which the rear part extends.
Sole (2) according to claim 6 and according to the preceding claim, characterized in that said stiffening ribs (71, 72, 73) are arranged on the closed contour of said openings (51, 52, 53, 54, 55, 56, 57).
Sole (2) according to one of the preceding claims, characterized in that the rear part (21) of the reinforcing element (11) comprises an internal lateral edge (65) extending upwards and intended to extend along an internal lateral edge of the plantar fascia (44), and/or in that the rear part of the reinforcing element comprises an external lateral edge (66) extending upwards and intended to extend along an external lateral edge of the plantar fascia (44).
Sole (2) according to one of the preceding claims, characterized in that the rear part (21) of the reinforcing element (11) comprises a rear notch (58) configured to move the rear support point (41) away from a rear edge of the reinforcing element by at least one centimeter.
Sole (2) according to one of the preceding claims, characterized in that the central hinge (23) forms a narrowest zone of the reinforcing element along a transverse axis (Y).
Sole (2) according to one of the preceding claims, characterized in that the reinforcing element (11) is a monolithic element made of plastic and obtained by molding.
Sole (2) according to one of the preceding claims, characterized in that it comprises an upper part (7) provided with an upper surface (8) intended to receive a lower surface of a foot, the upper part comprising an upper shock-absorbing layer (16), the upper part (7) extending above the reinforcing element (11),
and/or in that it comprises a lower part (9) provided with a lower surface (10) intended to come into contact with the ground, the lower part comprising a lower damping layer (12), the lower part (9) extending above the reinforcing element (11).
Sole (2) according to one of the preceding claims, characterized in that the reinforcing element comprises an internal face (81) visible on an internal side of the sole and/or an external face (82) visible on an external side of the sole.
Sports shoe (1), in particular a sports shoe suitable for running, preferably on uneven terrain, comprising a sole according to one of the preceding claims.