SOLE ELEMENT FOR CUSTOMIZABLE FOREFOOT STIFFNESS

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. 102024136555.2, filed Dec. 6, 2024, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

Some embodiments of the present disclosure relate to sole elements adapted to be arranged in a shoe, such as a sports shoe. In some embodiments, the sole element is a strobel board and/or an insole. The sole element may comprise means for stiffening at least a portion of the sole element, wherein the at least a portion of the sole element may be located in a region adapted to receive a forefoot. The sole element may be adapted to be arranged in the shoe when wearing the shoe.

BACKGROUND

Improving the performance of an athlete, for example, is often at the very heart of the development and evolution of sporting goods. This may be applicable to sport shoes, e.g., running shoes, where the performance of the athlete often depends on the performance of the shoe. Therefore, effort has been made to optimize the performance of sport shoes, such as running shoes.

A benchmark for the assessment of the performance of a shoe may be the energy return and/or the propulsion of the shoe. For example, the energy return and/or the propulsion of the shoe may be steered by a stiffness of the shoe. For example, a higher energy return and/or a higher propulsion may be achieved by increasing the stiffness of the shoe.

Often, a shoe is manufactured with a predefined stiffness, which generally cannot be adapted after completion of the manufacturing process, thereby generally rendering the stiffness, the energy return, and/or the propulsion a permanent property of the shoe. But different athletes may prefer different stiffness of the shoe, and the performance of an athlete may be significantly diminished when, e.g., the stiffness of the shoe does not match the particular preferences of the athlete.

Therefore, there is a need to address the above-described deficiencies of current shoes.

BRIEF SUMMARY

A first embodiment (I) of the present disclosure is directed to a sole element adapted to be arranged in a shoe, such as a sports shoe, wherein: the sole element comprises means for stiffening at least a portion of the sole element, the at least a portion of the sole element is located at least in a region adapted to receive a forefoot, the sole element is adapted to be arranged in the shoe when wearing the shoe, and the sole element is a strobel board and/or an insole.

In a second embodiment (II), the means for stiffening at least a portion of the sole element according to the first embodiment (I) is/are adapted to: stiffen at least a portion of the shoe adapted to receive a forefoot; and/or stiffen at least a portion of the shoe adapted to receive a midfoot, and/or the means for stiffening is/are arranged such as to extend from the portion of the shoe adapted to receive a forefoot towards the portion of the shoe adapted to receive a midfoot.

In a third embodiment (III), wherein to stiffen at least a portion of the shoe adapted to receive a forefoot and/or a midfoot according to the second embodiment (II) comprises to increase the propulsion and/or to reduce a stud pressure associated with the shoe.

In a fourth embodiment (IV), the sole element according to any one of embodiments (I)-(III) is arranged in the shoe such that at least a portion of the sole element is exchangeable, and/or wherein at least a portion of the means for stiffening is exchangeable.

In a fifth embodiment (V), the at least a portion of the sole element which is exchangeable according to the fourth embodiment (IV) is adapted to be exchanged and/or removed through an opening of the shoe, and/or is adapted to be exchanged and/or removed through an ankle opening of the shoe.

In a sixth embodiment (VI), the means for stiffening according to any one of embodiments (I)-(V) comprise(s) a pocket adapted to receive a stiffening element, and/or the pocket is adapted to receive the stiffening element through an opening.

In a seventh embodiment (VII), the pocket according to the sixth embodiment (VI) is comprised within the strobel board and/or the pocket is at least partially attached to the strobel board, and/or the pocket is attached to the strobel board via stitching and/or knitting.

In an eighth embodiment (VIII), the pocket according to any one of embodiments (VI)-(VII) is arranged on a side of the strobel board adapted to face an inside of the shoe.

In a ninth embodiment (IX), the pocket according to any one of embodiments (VI)-(VIII) comprises means for fixing the stiffening element and/or comprises a hook-and-loop fastener for fixing the stiffening element.

In a tenth embodiment (X), the means for stiffening according to any one of embodiments (I)-(IX) comprises a stiffening plate.

In an eleventh embodiment (XI), the means for stiffening according to any one of embodiments (I)-(X) comprise(s) a stiffening element which is at least partially attached to the strobel board.

In a twelfth embodiment (XII), the stiffening element according to the eleventh embodiment (XI) is attached to the strobel board by gluing and/or stitching.

In a thirteenth embodiment (XIII), at least a portion of the means for stiffening according to any one of embodiments (I)-(XII) is injected into the strobel board.

In a fourteenth embodiment (XIV), the strobel board according to any one of embodiments (I)-(XIII) comprises a non-woven material.

In a fifteenth embodiment (XV), the means for stiffening according to any one of embodiments (I)-(XIV) is/are at least partially attached to the insole of the shoe, and/or the means for stiffening is/are attached to a side of the insole adapted to face the strobel of the shoe and/or a midsole of the shoe.

A sixteenth embodiment (XVI) of the present disclosure is directed to a shoe, such as a sports shoe, comprising the sole element according to any one of embodiments (I)- (XV).

SHORT DESCRIPTION OF THE FIGURES

The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of the present disclosure. Together with the description, the figures further serve to explain the principles of and to enable a person skilled in the relevant art(s) to make and use the disclosed embodiments. These figures are intended to be illustrative, not limiting. Although the disclosure is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the drawings, like reference numbers indicate identical or functionally similar elements.

FIG. 1A shows a strobel board comprising a stiffening plate arranged inside a closed pocket, wherein the pocket is closed via a hook-and-loop fastener, according to some embodiments;

FIG. 1B shows a strobel board comprising a stiffening plate, wherein a part of the stiffening plate is arranged outside of the opened pocket, according to some embodiments;

FIG. 2 shows a strobel board comprising a stiffening plate, wherein the stiffening plate is attached to the strobel board via stitching, according to some embodiments;

FIG. 3 shows a strobel board comprising a stiffening plate, wherein the stiffening plate is attached to the strobel board via gluing, according to some embodiments;

FIG. 4A shows a strobel board, wherein at least a portion of the means for stiffening is/are injected into a forefoot portion of the strobel board, according to some embodiments;

FIG. 4B shows a strobel board, wherein at least a portion of the means for stiffening is/are injected such into the strobel board that the means for stiffening extend from the forefoot portion to a midfoot portion of the strobel board, according to some embodiments;

FIG. 4C shows a strobel board, wherein at least a portion of the means for stiffening is/are injected such into the strobel board that a centre portion of the means for stiffening is located at a midfoot portion of the strobel board, according to some embodiments;

FIG. 5A shows a schematic illustration of a strobel board comprising a stiffening plate arranged inside a pocket of the strobel board, according to some embodiments;

FIG. 5B shows a schematic illustration of the strobel board illustrating the insertion of the stiffening plate into the pocket of the strobel board, according to some embodiments;

FIG. 5C shows a schematic illustration of a stiffening plate adapted to be received in the pocket of the strobel board, according to some embodiments.

DETAILED DESCRIPTION

In the following, only some possible embodiments of the present disclosure are described in detail. It is to be understood that these exemplary embodiments may be modified in a number of ways and combined with each other whenever compatible and that certain features may be omitted in so far as they are dispensable.

Where a range of numerical values comprising upper and lower values is recited herein, unless otherwise stated in specific circumstances, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the disclosure or claims be limited to the specific values recited when defining a range. Further, when an amount, concentration, or other value or parameter is given as a range, one or more ranges, or as list of upper values and lower values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or value and any lower range limit or value, regardless of whether such pairs are separately disclosed.

Some embodiments of the present disclosure relate to a sole element adapted to be arranged in a shoe, such as a sports shoe. In some embodiments, the sole element is a strobel board and/or an insole and the sole element may comprise means for stiffening at least a portion of the sole element. For example, in some embodiments, the at least a portion of the sole element may be located at least in a region adapted to receive a forefoot. In some embodiments, the sole element may be adapted to be arranged in the shoe when wearing the shoe.

For example, in some embodiments, the strobel board and/or the insole may be adapted to be arranged in the shoe. Being adapted to be arranged in the shoe may comprise that the sole element is fixedly attached to the shoe. For example, in some embodiments, the sole element may be arranged in the shoe such as to be an integral part of the shoe. For example, in some embodiments, the sole element may be permanently attached to at least a part of the shoe, e.g., an upper of the shoe and/or a midsole of the shoe. In some embodiments, for example, the strobel board may be arranged in the shoe such as to be an integral part of the shoe. In some embodiments, being adapted to be arranged in the shoe may comprise that the sole element is configured such that the shole element may be received by the shoe. For example, in some embodiments, a size and/or a geometry and/or a thickness of the sole element may be such that the shoe may receive the sole element. In some embodiments, for example, the insole may be adapted such that the insole can be received by the shoe, e.g., by placing the insole inside the shoe.

In some embodiments, the sole element may comprise means for stiffening at least a portion of the sole element. In some embodiments, the means for stiffening may comprise at least one means for stiffening the at least a portion of the sole element. In some embodiments, the means for stiffening may be adapted such that the at least portion of the sole element that is stiffen by the means for stiffening is located in a region adapted to receive a forefoot. In some embodiments, the region adapted to receive the forefoot may comprise a region that receives at least a portion of the forefoot when the sole element is arranged in the shoe. For example, in some embodiments, the forefoot region may comprise a region associated with a toe and/or phalanges of the foot.

In some embodiments, being adapted to be arranged in the shoe when wearing the shoe may comprise that the sole element is arranged in the shoe when a wearer (e.g., an athlete) is wearing the shoe for performing activities (e.g., athletic activities). For example, in some embodiments, the sole element may be adapted to be arranged in the shoe at least during a use of the shoe, e.g., performing activities (e.g., athletic activities) such as walking and/or running.

In some embodiments, stiffening at least a portion of the sole element located in a region adapted to receive a forefoot may allow for an adaption of the forefoot stiffness of the sole element. For example, in some embodiments, adapting the forefoot stiffness of the sole element may enable a localized and specific adaption of the responsiveness and/or an energy return of a shoe comprising the sole element. Thereby, in some embodiments, the forefoot stiffness and/or the responsiveness of the shoe may be adapted to the athletes needs and thus may optimize the performance of the athlete and enhance the wearing comfort of the shoe.

In some embodiments, the means for stiffening at least a portion of the sole element may be adapted to stiffen at least a portion of the shoe adapted to receive a forefoot. In some embodiments, the means for stiffening at least a portion of the sole element may be adapted to stiffen at least a portion of the shoe adapted to receive a midfoot. For example, in some embodiments, the means for stiffening may be arranged such as to extend from a portion of the shoe adapted to receive a forefoot towards the portion of the shoe adapted to receive a midfoot.

In some embodiments, to stiffen at least a portion of the shoe adapted to receive a forefoot and/or a midfoot may comprise to increase the propulsion associated with the shoe. In some embodiments, to stiffen at least a portion of the shoe adapted to receive a forefoot and/or midfoot may comprise to reduce a stud pressure associated with the shoe.

In some embodiments, for example, the means for stiffening may be arranged such that, when the sole element is arranged in the shoe, the means for stiffening may stiffen(s) a portion of the shoe adapted to receive a portion of the forefoot. For example, in some embodiments, the means for stiffening may stiffen the portion of the sole element and the portion of the shoe. In some embodiments, for example, the stiffening of the portion of the shoe may be based on the stiffening of the portion of the sole element. For example, in some embodiments, the stiffening of the portion of the sole element by the means for stiffening may induce, when the sole element is arranged in the shoe, a stiffening of the portion of the shoe. In some embodiments, the at least a portion of the shoe stiffened by the means for stiffening may essentially correspond to the at least a portion of the sole element stiffened by the means for stiffening. In some embodiments, the at least a portion of the shoe stiffened by the means for stiffening may be a sub-portion of the at least a portion of the sole element stiffened by the means for stiffening. In some embodiments, the at least a portion of the shoe stiffened by the means for stiffening may be a super-portion of the at least a portion of the sole element stiffened by the means for stiffening.

In some embodiments, the means for stiffening may stiffen the at least a portion of the sole element and/or the shoe such as to increase the propulsion associated with the shoe. For example, in some embodiments, the propulsion associated with the shoe may comprise an energy return associated with the shoe. In some embodiments, for example, by stiffening the at least a portion of shoe adapted to receive a forefoot, the energy return of the shoe may be increased. For example, an energy return of the shoe associated with the forefoot region may be increased in some embodiments. Increasing the energy return associated with the forefoot region of the shoe may minimize the energy loss of the shoe and may thereby optimize the performance of a wearer (e.g., an athlete) wearing the shoe. For example, in some embodiments, an enhanced energy return of the portion of the shoe adapted to receive the forefoot may be advantageous for athletes performing forefoot running.

In some embodiments, the means for stiffening may stiffen the at least a portion of the sole element and/or the shoe such as to reduce the stud pressure associated with the shoe. In some embodiments, reducing the stud pressure associated with the shoe may comprise reducing a pressure and/or force that a stud may exert on the sole element and/or the shoe based on a weight of the athlete wearing the shoe. For example, in some embodiments, the stiffening of the at least a portion of the sole element and/or the shoe may allow for distributing the force which the stud exerts on the shoe and/or sole element and/or foot over a larger region and may thereby minimize the pressure (force per area). Thus, in some embodiments, stiffening the at least a portion of the sole element and/or shoe may enhance the wearing comfort of the shoe comprising the sole element and may thereby contribute to an improved performance of the athlete. For example, in some embodiments, reduced stud pressure and increased propulsion and/or energy return may generate a synergistic effect which may enable the wearer (e.g., the athlete) wearing the shoe to achieve improved performance.

In some embodiments, the sole element may be arranged in the shoe such that at least a portion of the sole element is exchangeable. For example, in some embodiments, the at least a portion of the sole element which may exchangeable may comprise the means for stiffening.

In some embodiments, arranging the sole element in the shoe such that at least a portion of the sole element may be exchangeable may comprise that the at least portion of the sole element may be exchanged without substantially affecting other components of the sole element and/or the shoe. For example, in some embodiments, the at least a portion of the sole element may be not permanently fixed to other components of the shoe and/or midsole (e.g., the at least a portion of the sole element may not fixed to other components via gluing and/or stitching). In some embodiments, arranging the sole element in the shoe such that at least a portion of the sole element is exchangeable may comprise that the at least portion of the sole element can be exchanged based on the wearer's needs (e.g., the athlete's needs). In some embodiments, the at least a portion of the sole element which is exchangeable may be located in a region adapted to receive a forefoot. In some embodiments, the at least a portion of the sole element that is exchangeable may comprise essentially the sole element (e.g., the sole element itself may be exchangeable). For example, in some embodiments, when the sole element comprises the insole, the sole element may be exchangeable.

In some embodiments, by arranging the sole element such that at least a portion of the sole element is exchangeable, such as a portion the means for stiffening, the stiffness of the sole element and/or the shoe may be steered based on the wearer's needs (e.g., the athlete's needs). For example, in some embodiments, the at least a portion of the means for stiffening which is/are exchangeable may be exchanged and/or replaced by a different at least a portion of the means for stiffening. For example, in some embodiments, a first portion of the means for stiffening may be exchanged and/or replaced by a second portion of the means for stiffening.

In some embodiments, the first portion of the means for stiffening and the second portion of the means for stiffening may comprise different stiffening properties (e.g., the first portion may comprise first stiffening properties and the second portion may comprise second stiffening properties). For example, in some embodiments, the first stiffening properties of the first portion may be such as to induce a first stiffness of the sole element and/or the shoe. In some embodiments, the second stiffening properties of the second portion may be such as to induce a second stiffness of the sole element and/or the shoe. For example, in some embodiments, the second stiffening properties of the second element may be such that at least a portion of the sole element and/or shoe comprising the second element is stiffer than at least a portion of the sole element and/or shoe comprising the first portion.

In some embodiments, the at least a portion of the sole element which is exchangeable may be adapted to be exchanged and/or removed through an opening of the shoe. For example, in some embodiments, the at least a portion of the sole element which is exchangeable may be adapted to be exchanged and/or removed through an ankle opening of the shoe.

Exchanging and/or removing the at least a portion of the sole element through an opening of the shoe may allow for an easy and fast exchange of the at least a portion of the sole element. For example, in some embodiments, exchanging and/or removing the at least a portion of the sole element through an ankle opening of the shoe may allow for exchanging and/or removing the at least a portion of the sole element through a natural opening of the shoe (e.g., an opening that a shoe necessarily has). For example, in some embodiments, when the at least a portion of the sole element is exchanged and/or removed through the ankle opening of the shoe, further and/or additional openings may not be introduced into the shoe (e.g., further and/or additional openings may not be introduced into a midsole of the shoe). Thereby, in some embodiments, the manufacturing process of the shoe may be simplified and accelerated. In some embodiments, the stability of the shoe may be improved as further openings (e.g., areas without a material) may not be introduced.

In some embodiments, the means for stiffening may comprise a pocket adapted to receive a stiffening element. For example, in some embodiments, the pocket may be adapted to receive the stiffening element through an opening.

In some embodiments, the pocket may be located in a region adapted to receive a forefoot. In some embodiments, the pocket may comprise a size and/or a geometry such that the pocket can receive the stiffening element. In some embodiments, a pocket may comprise and/or define a cavity. For example, in some embodiments, the pocket may comprise a size and/or a geometry such that a size and/or geometry of the cavity essentially corresponds to a size and/or a geometry of the stiffening element. In some embodiments, the pocket may comprise an opening, e.g., an access to the cavity, through which the stiffening element can be received. For example, in some embodiments, the pocket may be adapted such that the opening points towards the opening of the shoe, when the sole element is arranged in the shoe. In some embodiments, the pocket may be adapted such that the opening of the pocket points towards the ankle opening of the shoe.

In some embodiments, the opening of pocket may be such that the stiffening element may be removed from the pocket. For example, in some embodiments, the pocket may be adapted such that the stiffening element can be exchanged. In some embodiments, for example, the pocket may receive a first stiffening element comprising first stiffening properties. Afterwards, in some embodiments, the first stiffening element may be removed through the opening of the pocket and a second stiffening element comprising second stiffening properties may be received.

In some embodiments, means for stiffening comprising a pocket adapted to receive a stiffening element may enable an efficient and simple exchange and/or replacement of the stiffening element. An efficient and simple exchange and/or replacement of the stiffening element may contribute to an improved adjustment of the propulsion and/or energy return and/or stud pressure of the shoe.

In some embodiments, the pocket may be comprised within the strobel board. In some embodiments, the pocket may be at least partially attached to the strobel board. For example, in some embodiments, the pocket may be at least partially attached to the strobel board via stitching. In some embodiments, the pocket may be at least partially attached to the strobel board via knitting.

In some embodiments, the pocket may be an integral part of the strobel board (e.g., the strobel and the pocket may be one piece). For example, in some embodiments, a first portion of the pocket may extend from the strobel board, and a second portion of the pocket may be comprised within the strobel board. In some embodiments, at least a portion of an inner side of the cavity of the pocket may be formed by the strobel board.

In some embodiments, a pocket which is comprised within the strobel board may allow for the use of a one-piece strobel board. A one-piece strobel board may enhance the stability of the pocket and contribute to the longevity of the strobel board. In some embodiments, a pocket comprised within the strobel board may allow for attaching the pocket to the strobel board without creating seams, thereby contributing to an improved wearing comfort of the shoe.

In some embodiments, at least a portion of the pocket may be attached to the strobel board. For example, in some embodiments, the pocket may be attached such to the strobel board that a portion of the pocket is formed by the strobel board. In some embodiments, a separate pocket may be attached to the strobel board. For example, in some embodiments, a prefabricated pocket forming a cavity by itself may be attached to the strobel board.

In some embodiments, the pocket may be attached to the strobel board via stitching. For example, in some embodiments, the pocket may be attached to the strobel board via stitching an outer region and/or a boundary region of the pocket to the strobel. In some embodiments, the pocket may be attached to the strobel board via knitting. For example, in some embodiments, the pocket may be attached to the strobel board via knitting an outer region and/or a boundary region of the pocket to the strobel.

Attaching the pocket to the strobel board via stitching and/or knitting may allow for a simplified creation of the pocket at the strobel board. In some embodiments, attaching the pocket to the strobel board via stitching and/or knitting may improve the quality of the attachment, e.g., an attachment which is particularly resistant against external forces, thereby contributing to the longevity of the strobel board.

In some embodiments, the pocket may be arranged on a side of the strobel board adapted to face an inside of the shoe.

For example, in some embodiments, the pocket may be at least partially attached to a side of the strobel board adapted to face an inside of the shoe. In some embodiments, the pocket may be comprised within the strobel board such that at least a portion of the pocket extends from a side of the strobel board adapted to face an inside of the shoe. For example, in some embodiments, the pocket may be arranged on a side of the strobel board such that the opening of the pocket is arranged on a side of the strobel board adapted to face the inside of the shoe.

In some embodiments, facing an inside of the shoe may comprise that at least a portion of the side of the strobel board is covered by components of the shoe. For example, in some embodiments, the at least a portion of the side of the strobel board may be covered by an insole. In some embodiments, the side of the strobel board adapted to face an inside of the shoe may be not directly (optically) accessible (e.g., visible through the ankle opening of the shoe) but may be covered by an insole of the shoe.

In some embodiments, arranging the pocket on a side of the strobel board adapted to face an inside of the shoe may enable the arrangement of the opening of the pocket on a side of the strobel board adapted to face an inside of the shoe. In some embodiments, arranging the opening of the pocket on a side of the strobel board adapted to face an inside of the shoe may facilitate the exchange of the stiffening element. For example, in some embodiments, arranging the opening of the pocket on a side of the strobel board adapted to face an inside of the shoe may allow at least a portion of the pocket (e.g., the opening of the pocket) to be (directly) accessible through the opening of the shoe (e.g., the ankle opening). Thereby, in some embodiments, a first stiffening element received in the pocket may be removed from the pocket through opening of the pocket and through the ankle opening of the shoe and a second stiffening element may be inserted into the pocket through the ankle opening and the opening of the pocket. Thus, in some embodiments, arranging the pocket on a side of the strobel board adapted to face an inside of the shoe may improve the exchangeability of the portion of the means for stiffening, e.g., the stiffening element.

In some embodiments, the pocket may comprise means for fixing the stiffening element. For example, in some embodiments, the means for fixing may comprise a hook-and-loop fastener.

In some embodiments, the means for fixing the stiffening element may comprise means for maintaining the stiffening element within the pocket. For example, in some embodiments, the means for fixing the stiffening element may comprise means for at least partially closing the opening of the pocket. In some embodiments, the means for fixing may be adapted such that the stiffening element can be unfastened. For example, in some embodiments, the means for fixing the stiffening element may comprise means for reversibly fixing the stiffening element. In some embodiments, the means for fixing the stiffening element may comprise a hook-and-loop fastener. In some embodiments, the means for fixing the stiffening element may comprise at least one button, such as a push button. In some embodiments, at least a portion of the means for fixing the stiffening element may be arranged on a side of the strobel board adapted to face an inside of the shoe.

In some embodiments, a pocket comprising means for fixing the stiffening element, e.g., a hook-and-loop fastener for closing at least a portion of the opening of the pocket, may allow for fixing and maintaining the stiffening element in an intended and/or preconfigured position. For example, in some embodiments, the means for fixing the stiffening element may allow for maintaining the stiffening element within the pocket and thereby may promote the stiffening element remaining within a region of the strobel board adapted to receive a forefoot. Thus, in some embodiments, when wearing the shoe, for example, the stiffening element may remain within the pocket and stiffen a region of the strobel board and/or shoe adapted to receive a forefoot, and thereby may improve the energy return of the shoe, minimize the stud pressure associated with the shoe, and improve the performance of a wearer (e.g., an athlete) wearing the shoe.

In some embodiments, the means for stiffening may comprise a stiffening plate.

In some embodiments, a stiffening plate may comprise that an extension of the stiffening plate in a first direction is substantially smaller than an extension in a second direction. For example, in some embodiments, a thickness associated with the stiffening plate may be substantially smaller than a planar extension of the stiffening plate. In some embodiments, the stiffening plate may comprise a contiguous and/or connected plate. In some embodiments, the stiffening plate may comprise at least one recess. In some embodiments, the stiffening plate may comprise at least one aperture.

In some embodiments, the stiffening plate may be adapted to be received in the pocket of the strobel board. For example, in some embodiments, a size and/or shape of the stiffening plate may be configured such as to enable the stiffening plate to be received by the pocket.

In some embodiments, means for stiffening comprising a stiffening plate may enable the stiffening of the strobel board and/or the shoe by an element with a small thickness, thereby minimizing variations of the form of the strobel board when the stiffening plate is placed inside the pocket. In some embodiments, using a stiffening plate may minimize the formation of bulges within the strobel board and/or deformations of the strobel board, when the stiffening plate is placed in the pocket, for example. The minimization the formation of bulges within the strobel board and/or deformations of the strobel board may contribute to an improved wearing comfort of the shoe.

In some embodiments, the means for stiffening may comprise a stiffening element which may be at least partially attached to the strobel board. In some embodiments, the means for stiffening may comprise a stiffening element which is at least partially attached to the strobel board by gluing. In some embodiments, the means for stiffening may comprise a stiffening element which is at least partially attached to the strobel board by stitching.

In some embodiments, the stiffening element may be attached to the strobel board at a boundary and/or outer region of the stiffening element. For example, in some embodiments, at least a portion of the boundary and/or outer region of the stiffening element may be sewn and/or stitched to the strobel board. In some embodiments, the stiffening element may be adapted such that at least a portion of the boundary and/or outer region of the stiffening element follows a portion of the boundary and/or outer region of the strobel board. For example, in some embodiments, a portion of the boundary and/or outer region of the stiffening element may be sewn and/or stitched to a portion of the boundary and/or outer region of the strobel board. In some embodiments, at least a portion of the stiffening element may be attached to the strobel board by gluing. For example, in some embodiments, gluing a portion of the stiffening element to the strobel board may comprise that at least a centre portion and/or mid-portion of the stiffening element is glued to the strobel board. In some embodiments, the stiffening element may be glued to the strobel board essentially across the complete surface of the stiffening element facing the strobel board.

Attaching the stiffening element at least partially to the strobel board by gluing and/or stitching may facilitate the attachment of the stiffening element and promote a stable attachment (e.g., an attachment resistant against external forces).

In some embodiments, the stiffening element and/or the stiffening plate may comprise at least one aperture. For example, in some embodiments, the stiffening element and/or the stiffening plate may comprise at least 2, at least 3, or at least 4 apertures. In some embodiments, the at least one aperture may comprise an elliptical geometry. For example, in some embodiments, a major-semi axis of the elliptical geometry may be essentially parallel to a direction of elongation of the strobel board and/or shoe. In some embodiments, the stiffening element and/or the stiffening plate may comprise a rib-like structure. In some embodiments, the at least one aperture of the stiffening element and/or the stiffening plate may be separated by at least one rib. In some embodiments, the stiffening element and/or the stiffening plate may comprise at least one, at least two, or at least three ribs. In some embodiments, the stiffening element and/or the stiffening plate may comprise a lattice and/or cell structure.

In some embodiments, a stiffening element and/or stiffening plate with at least one aperture, such as an aperture arranged in a rib-and/or lattice-and/or cell-like structure, may allow for stiffening of the strobel board and the shoe comprising the strobel board while minimizing the weight of the stiffening element and/or stiffening plate.

In some embodiments, the stiffening element and/or the stiffening plate may comprise at least one finger. For example, in some embodiments, the stiffening element and/or the stiffening plate may be adapted such that the at least one finger extends to medial forefoot portion of the strobel board. In some embodiments, the at least one finger of the stiffening element and/or the stiffening plate may extend such to the medial forefoot portion of the strobel board that the at least one finger is located in a region of the strobel board associated with a hallux of a foot. In some embodiments, the stiffening element and/or the stiffening plate may be adapted such that the at least one finger extends to a lateral and/or central midfoot portion of the strobel board. In some embodiments, the length of the at least one finger may be at least 0.5 cm, at least 1 cm, at least 1.5 cm, at least 2 cm, or at least 2.5 cm.

In some embodiments, at least a portion of the means for stiffening may be injected into the strobel board.

For example, in some embodiments, injecting at least a portion of the means for stiffening into the strobel board may comprise injecting at least a portion of the means for stiffening into a pre-manufactured strobel board. In some embodiments, the at least a portion of the means for stiffening may be injected such into the strobel board as to form an insole board. For example, in some embodiments, injecting the at least a portion of the means for stiffening into the strobel board may comprise arranging a textile, e.g., the strobel, in a mould. In some embodiments, the textile may comprise a non-flammable material. In some embodiments, the non-inflammable material may comprise a non-woven material. In some embodiments, injecting the at least a portion of the means for stiffening into the strobel board may further comprise injecting a material into and/or onto the textile, e.g., into and/or onto the strobel board. For example, in some embodiments, the material may be injected into and/or onto the non-woven material. In some embodiments, the material may be injected such into the textile that the material at least partially infiltrates the textile, e.g., the non-woven material. In some embodiments, the (injected) material may comprise polyamide. In some embodiments, the (injected) material may comprise a thermoplastic elastomer. For example, in some embodiments, the thermoplastic elastomer may comprise polyether block amide.

In some embodiments, the at least portion of the means for stiffening may be injected such into the strobel board that the at least portion of the means for stiffening is located in a forefoot region of the strobel board. In some embodiments, the means for stiffening may be injected such into the strobel board that the at least portion of the means for stiffening is located in a midfoot region of the strobel board. For example, in some embodiments, the means for stiffening may be injected such into the strobel board that the at least portion of the means for stiffening extends from the forefoot portion of the strobel board to a midfoot region of the strobel board. In some embodiments, injecting the means for stiffening into a midfoot region of the strobel board may enable the provision of a midfoot stiffness of the strobel board, thereby improving the propulsion and/or energy return of the shoe and thus improving the performance of a wearer (e.g., an athlete). Moreover, in some embodiments, injecting the means for stiffening into the strobel board such that the means for stiffening extends from the forefoot portion of the strobel board to the midfoot portion of the strobel board may allow for the simultaneous stiffening of the forefoot portion of the strobel and the midfoot portion of the strobel. Such configurations may improve the propulsion and/or energy return of the shoe and may improve the performance of the wearer (e.g., the athlete).

In some embodiments, at least a portion of the means for stiffening may be casted and/or poured onto the strobel board. For example, in some embodiments, the means for stiffening may be casted and/or poured onto a side of the strobel board adapted to receive a foot. In some embodiments, the means for stiffening may be casted and/or poured onto a side of the strobel board opposite to the side of the strobel board adapted to receive a foot. In some embodiments, casting and/or pouring the means for stiffening onto the strobel board may comprise casting and/or pouring a material onto the strobel board. For example, in some embodiments, the material may comprise polyurethane.

In some embodiments, the strobel board may comprise a non-woven material. In some embodiments, the strobel board may comprise a knitted material. For example, in some embodiments, the strobel board may be a knitted strobel board. In some embodiments, the strobel board may comprise a woven material. In some embodiments, the strobel board may comprise a non-flammable material. In some embodiments, the strobel board may comprise a material with a limited stretchability. For example, in some embodiments, the strobel board may comprise an essentially non-stretchable material. In some embodiments, a strobel board comprising a material with a limited stretchability may facilitates an application of a strobel stitch (e.g., stitching the strobel board to a shoe).

In some embodiments, the means for stiffening may be attached to and/or injected into the strobel board such that a boundary of the means for stiffening and a boundary of the strobel board are spaced apart. In some embodiments, spacing apart the boundary of the means for stiffening and the boundary of the strobel board may comprise that the boundary of the means for stiffening and the boundary of the strobel board are separated by a distance. For example, in some embodiments, the boundary of the means for stiffening and the boundary of the strobel board may be spaced apart such that the distance between the boundary of the means for stiffening and the boundary of the strobel board is essentially uniform along the boundary of the means for stiffening and/or the boundary of the strobel board.

In some embodiments, the distance between the boundary of the means for stiffening and the boundary of the strobel board may be at least 5 mm, at least 10 mm, at least 15 mm, at least 20 mm, or at least 25 mm. In some embodiments, the distance between the boundary of the means for stiffening and the boundary of the strobel board may be at most 10 cm, at most 8 cm, at most 6 cm, at most 4 cm, or at most 2 cm. In some embodiments, the distance between the boundary of the means for stiffening and the boundary of the strobel board may at most 1.5 cm, at most 1 cm, at most 0.8 cm, at most 0.6 cm, or at most 0.4 cm.

In some embodiments, the shape and/or the size of the means for stiffening may be adapted such as to essentially correspond to a rescaling of a shape and/or size of a portion of the strobel board. For example, in some embodiments, the shape and/or size of the means for stiffening may be adapted such as to essentially correspond to a rescaling of a shape and/or size of a forefoot portion of the strobel board. In some embodiments, the shape and/or size of the means for stiffening may be adapted such as to essentially correspond to a rescaling of a shape and/or size of a midfoot portion of the strobel board. For example, in some embodiments, the shape and/or the size of the means for stiffening may be rescaled such as to space apart the boundary of the means for stiffening and the boundary of the strobel board. In some embodiments, the shape and/or the size of the means for stiffening may comprise a rescaling of a shape and/or a size of a portion of the strobel board by a factor of at least 0.8, at least 0.85, at least 0.9, at least 0.92, or at least 0.95.

In some embodiments, the means for stiffening may be at least partially attached to the insole of the shoe. For example, in some embodiments, the means for stiffening may be attached to a side of the insole adapted to face the strobel of the shoe. In some embodiments, or alternatively, the means for stiffening may be attached to a side of the insole adapted to face a midsole of the shoe.

In some embodiments, the side of the insole adapted to face a midsole of the shoe may comprise a side of the insole opposite to the side of the insole adapted to face the strobel of the shoe. In some embodiments, the means for stiffening may be injected into the insole of the shoe. In some embodiments, the means for stiffening may be cemented and/or glued to the insole of the shoe. In some embodiments, the insole of the shoe may comprise a sockliner. For example, in some embodiments, the means for stiffening may be injected and/or cemented and/or glued to the sockliner such that the means for stiffening are arranged at a side of the sockliner adapted to face a midsole of the shoe.

In some embodiments, the means for stiffening may be attached to and/or injected into a portion of the insole, e.g., a midfoot portion of the insole and/or a forefoot portion of the insole. In some embodiments, an area of the insole may be associated with the means for stiffening. For example, in some embodiments, the area of the sole associated with the means or stiffening may comprise an area of the portion of the insole to which the means for stiffening has/have been attached and/or an area of the portion of the insole into which the means for stiffening has/have been injected. In some embodiments, the area associated with the means for stiffening may be at least 40%, at least 50%, at least 60%, at least 70%, or at least 80% of a corresponding area of the insole. In some embodiments, the corresponding area of the insole, e.g., the area of the insole corresponding to the area of the means for stiffening, may comprise an area of a portion of the insole that surrounds and/or encompasses the means for stiffening. For example, in some embodiments, the portion of the insole that surrounds and/or encompasses the means for stiffening may surround and/or encompass the means for stiffening from a beginning of the means for stiffening to an end of the means for stiffening. In some embodiments, the beginning of the means for stiffening may be located in a forefoot portion of the insole. In some embodiments, the end point of the means for stiffening may be located in a mid-foot region and/or heel region of the insole.

In some embodiments, a shoe, e.g., a sports shoe, may be associated with at least two insoles. For example, in some embodiments, a first insole may be associated with a first stiffness and a second insole may be associated with a second stiffness. In some embodiments, the insole and/or the shoe may be adapted such that the insoles may be interchanged. For example, in some embodiments, the shoe may initially comprise the first insole (e.g., the first insole may be arranged within a cavity of the shoe). Then, in some embodiments, the first insole may be taken out of the shoe (e.g., taken out through an ankle opening of the shoe). In some embodiments, after the first insole has been taken out of the shoe, the second insole may be inserted into the cavity of the shoe (e.g., inserted through the ankle opening of the shoe). In some embodiments, a first means for stiffening may be attached to and/or injected into the first insole. In some embodiments, the first means for stiffening may be attached to and/or injected into a side of the first insole adapted to face a midsole of the shoe. For example, in some embodiments, the first means for stiffening may be adapted such as to increase a stiffness and/or propulsion of the shoe (e.g., the first means for stiffening may be adapted such as to increase a stiffness and/or propulsion of the shoe comprising the first insole). In some embodiments, the second insole may not comprise means for stiffening the insole (e.g., no additional material for stiffening the insole may be attached to and/or injected into the second insole). In some embodiments, the stiffness associated with the second insole corresponds to a stiffness of a typical, e.g., unstiffened, insole.

In some embodiments, associating the shoe, e.g., the sports shoe, with at least two (interchangeable) insoles, e.g., insoles with a different stiffness, may allow for adapting the stiffness of the shoe to the particular and individual needs of the wearer (e.g., the athlete). For example, in some embodiments, in a first situation where a flexible (e.g., low stiffness) and cushioned shoe is preferred, the wearer (e.g., the athlete) may select an insole from the at least two insoles that is associated with a low stiffness and/or without an additional stiffening means.

Some embodiments of the present disclosure relate to a shoe, such as a sports shoe. In some embodiments, the shoe comprises the sole element according to any one of the above-described embodiments.

FIGS. 1A and 1B show a sole element 100 adapted to be arranged in a shoe, according to some embodiments of the present disclosure. In some embodiments, the sole element 100 may comprise a stiffening plate 110, a strobel board 120, and a pocket 130. In some embodiments, the strobel board 120 comprises a non-woven material. In some embodiments, the pocket 130 may be arranged in a region 105a of the sole element 100 adapted to receive a forefoot. In some embodiments, the pocket 130 may be arranged in the region 105a of the sole element 100 such as to extend at least partially into a region 105b of the sole element 100 adapted to receive a midfoot. In some embodiments, the pocket 130 may be arranged in the region 105a of the sole element 100 such as to extend at least partially into the region 105b and a region 105c of the sole element 100 adapted to receive a rearfoot. In some embodiments, the pocket 130 may be attached to the strobel board 120 on a side of the strobel board 120 adapted to face an inside of a shoe. For example, in some embodiments, a portion of a boundary and/or an outer region of the pocket 130 may be attached to the strobel board 120.

In some embodiments, the size and the shape of the boundary and/or outer region of the pocket 130 may essentially follow the size and the shape of the strobel board 130 in the forefoot region 105 of the sole element. In some embodiments, the pocket 130 comprises an opening 132. A width of the opening 132, in some embodiments, may essentially correspond to a width associated with the strobel board 120 in a region associated with the opening 132.

As illustrated in FIG. 1B, the pocket 130 is adapted to receive the stiffening plate 110 in some embodiments. For example, in some embodiments, the size and the shape of the pocket 130 is such that the cavity formed by the pocket 130 may receive the stiffening element 110. In some embodiments, for example, the size and the shape of the pocket 130 essentially corresponds to the size and the shape of the stiffening plate 110. In some embodiments, the stiffening plate 110 comprises two recesses 115a, 115b, e.g., a first recess 115a in a rear portion of the stiffening plate 110 and a second recess 115b in a front portion of the stiffening plate. In some embodiments, the pocket 130 is adapted such that the cavity formed by the pocket essentially mirrors the recess 115b of the stiffening plate 110. For example, in some embodiments, a portion of the pocket 130 corresponding to the recess 115b may be attached to the strobel board 120. In some embodiments, the portion of the pocket 130 corresponding to the recess 115b is attached to the strobel board 120 such as to exclude the portion from the cavity formed by the pocket 130.

In some embodiments, the pocket 130 further comprises a hook-and-loop fastener 134. FIG. 1A illustrates the hook-and-loop fastener 134 in a closed configuration and FIG. 1B illustrates the hook-and-loop fastener 134 in an open configuration, according to some embodiments. The hook-and-loop fastener 134 may be adapted to open and/or to close at least a portion of the pocket 130. For example, in some embodiments, the hook-and-loop fastener may be adapted to close the at least a portion of the pocket 130 such as to prevent a (unintended) removing of the stiffening plate 110 from the pocket. In some embodiments, the hook-and-loop fastener 134 may be adapted to open the at least a portion of the pocket 130 such as to enable a (intended) removing and/or exchanging of the stiffening plate 110. For example, in some embodiments, the first recess 115a in the rear region of the stiffening plate 110 and the hook-and-loop fastener 134 are configured such that the hook-and-loop fastener 134 can be closed through the recess 115b. In some embodiments, the first recess 115a in the rear region of the stiffening plate 110 and the hook-and-loop fastener 134 may be configured such that the hook side (loop side) of the hook-and-loop fastener 134 contacts the opposing loop side (hook side) of the hook-and-loop fastener 134 through the recess 115b.

FIG. 2 shows a sole element 200, wherein the sole element 200 comprises a stiffening plate 210 and a strobel board 220, according to some embodiments of the present disclosure. In some embodiments, the strobel board 220 comprises a non-woven material. In some embodiments, the stiffening plate 210 may be arranged in at a portion 205a of the sole element 200 adapted to receive a forefoot. In some embodiments, the stiffening plate 210 may be arranged in the region 205a of the sole element 200 such as to extend at least partially into a region 205b of the sole element 200 adapted to receive a midfoot. In some embodiments, the stiffening element 210 may be arranged in the region 205a of the sole element 200 such as to extend at least partially into the region 205b and a region 205c of the sole element 200 adapted to receive a rearfoot.

In some embodiments, the stiffening element 210 may comprise two recesses 215a, 215b, e.g., a first recess 215a in a rear portion of the stiffening plate 210 and a second recess 215b in a front portion of the stiffening plate 210. In some embodiments, the stiffening plate 210 is attached to the strobel board 220. For example, in some embodiments, the stiffening plate 210 may be attached to the strobel board 220 by a stitching 230. In some embodiments, the stiffening plate 210 may be attached to the strobel board 220 by the stitching 230 essentially along the complete boundary and/or outer region of the stiffening plate 210. In some embodiments, the stiffening plate 210 may be attached to the strobel board 220 by a stitching 230 along a portion of the boundary and/or outer region of the stiffening plate. For example, in some embodiments, the stiffening plate 210 may be attached to the strobel board 220 by a stitching 230 only along a lateral boundary and/or a medial boundary of the stiffening plate 210, e.g., the stiffening plate 210 may not be stitched to the strobel board 220 along a portion of the boundary and/or outer region of the stiffening plate 210 associated with the recess 215a and/or the recess 215b.

FIG. 3 shows a sole element 300, wherein the sole element 300 comprises a stiffening plate 310 and a strobel board 320, according to some embodiments of the present disclosure. In some embodiments, the strobel board 320 may comprise a non-woven material. In some embodiments, the stiffening plate 310 may be arranged at a portion 305a of the sole element 300 adapted to receive a forefoot. In some embodiments, the stiffening plate 310 may be arranged in the region 305a of the sole element 300 such as to extend at least partially into a region 305b of the sole element 300 adapted to receive a midfoot. In some embodiments, the stiffening element 310 may be arranged in the region 305a of the sole element 300 such as to extend at least partially into the region 305b and a region 305c of the sole element 300 adapted to receive a rearfoot. In some embodiments, the stiffening element 310 comprises two recesses 315a, 315b, e.g., a first recess 315a in a rear portion of the stiffening plate 310 and a second recess 315b in a front portion of the stiffening plate 310. In some embodiments, the stiffening plate 310 may be attached to the strobel board 320. For example, in some embodiments, the stiffening plate 310 may be attached to the strobel board 320 by gluing the stiffening plate 310 to the strobel board 320.

FIG. 4A shows a sole element 400, wherein the sole element 400 comprises means for stiffening 410 at least a portion of the sole element 400, according to some embodiments of the present disclosure. In some embodiments, the means for stiffening 410 at least a portion of the sole element may be located in a region 405a adapted to receive a forefoot. In some embodiments, the sole element 400 further comprises a strobel board 420. In some embodiments, the strobel board 420 may comprise a non-woven material. In some embodiments, the strobel board may comprise a knitted and/or woven material. In some embodiments, the means for stiffening 410 is/are injected into the strobel board 420. For example, in some embodiments, the means for stiffening 410 may be injected such into the strobel board 420 as to infiltrate at least a portion of the strobel board 420 (e.g., the strobel board material). In some embodiments, the means for stiffening 410 may comprise polyamide and/or a thermoplastic elastomer (e.g., a polyether block amide).

In some embodiments, a shape of the means for stiffening 410 may essentially follow a shape of the strobel board 420. For example, in some embodiments, the shape of the means for stiffening 410 in the region 405a may essentially follow the shape of the strobel board 420 in the region 405a. In some embodiments, at least a portion of a boundary and/or outer region of the means for stiffening 410 may follow the boundary and/or outer region of the strobel board 420. In some embodiments, the means for stiffening 410 may be adapted and/or arranged such that the boundary of the means for stiffening 410 is at distance to the boundary of the strobel board 420. For example, in some embodiments, the distance between the boundary of the means for stiffening 410 and the strobel board 420 may be comprise a distance δ. In some embodiments, adapting and/or arranging the means for stiffening 410 such that the boundary of the means for stiffening 410 is at distance to the boundary of the strobel board 420 may comprise that a distance between the boundary of the means for stiffening 410 and the strobel board 420 is essentially uniform along the boundary of the means for stiffening 410 and/or along the boundary of the strobel board 420. For example, in some embodiments, the uniform distance may comprise the distance δ. In some embodiments, the means for stiffening 410 may be adapted such as to essentially correspond to a rescaling of a portion of the strobel board 420. For example, in some embodiments, the means for stiffening 410 may be adapted such as to correspond to a rescaling of a portion of the strobel board 420 in a forefoot region 405a. In some embodiments, the means for stiffening 410 may be rescaled such that the boundary of the means for stiffening 410 is at a distance δ to the boundary of the strobel board 420. The rescaling of the (complete) strobel board 420 is indicated by the dotted line 402 in, e.g., FIG. 4A. As shown in, e.g., FIG. 4A, a distance between the rescaled strobel board 402 (dotted line) and the boundary of the (not rescaled) strobel board 420 is δ.

FIG. 4B shows a sole element, according to some embodiments of the present disclosure. In some embodiments, the sole element 100 may comprise the strobel board 420 and means for stiffening 410 at least a portion of the strobel board 420. In some embodiments, the means for stiffening 410 is/are attached to and/or injected into a forefoot portion 405a of the strobel board 420 and attached to and/or injected into a midfoot portion 405b of the strobel board 420. In some embodiments, the means for stiffening is/are attached to and/or injected into a rearfoot/heel portion 405c of the strobel board 420. In some embodiments, the means for stiffening 410 is/are attached to and/or injected into the strobel board 420 such as to extend from the forefoot portion 405a of the strobel board 420 to the rearfoot/heel portion 405c of the strobel board 420.

FIG. 4C shows a sole element, according to some embodiments of the present disclosure. In some embodiments, the sole element 100 may comprise the strobel board 420 and means for stiffening 410 at least a portion of the strobel board 420. In some embodiments, the means for stiffening 410 is/are attached to and/or injected into the strobel board 420 such that a centre portion 414 of the means for stiffening 410 is located in a midfoot portion 405b of the strobel board 420. In some embodiments, the means for stiffening 410 extend(s) towards the forefoot portion 405a of the strobel board 420. In some embodiments, the means for stiffening 410 extend(s) towards the rearfoot/heel portion 405c of the strobel board 420. In some embodiments, two fingers 418a, 418b extend from the centre portion 414 of the means for stiffening 410 towards the forefoot portion 405a of the strobel board. In some embodiments, two fingers 418c, 418d extend from the centre portion 414 of the means for stiffening 410 towards the rearfoot/heel portion 405c of the strobel board 410. In some embodiments, the fingers 418a, 418b, 418c, 418d extend from the centre portion 414 such as to follow a (imaginary) boundary 402. For example, in some embodiments, the (imaginary) boundary may comprise a rescaled boundary of the strobel board 410.

FIG. 5A illustrates a sole element, according to some embodiments of the present disclosure. In some embodiments, the sole element may comprise a strobel board 520 and a pocket 530 is arranged at the strobel board 520. For example, in some embodiments, the pocket 530 may be comprised within the strobel board 520, e.g., the strobel board 520 and the pocket 530 may be one piece. In some embodiments, the pocket 530 may be attached to the strobel board 520, e.g., the pocket 530 may be stitched and/or glued to the strobel board 520. In some embodiments, the pocket is arranged on a side of the strobel board 520 adapted to face an insole and/or a foot. In some embodiments, the pocket 530 may be adapted to receive a stiffening element 510. As shown in FIG. 5A, in some embodiments, the stiffening element 510 may be arranged within the pocket 530, e.g., the stiffening element 510 may be inserted into the pocket 530. In some embodiments, the pocket 530 is arranged in a forefoot portion 505a of the strobel board 520, e.g., a portion of the strobel board 520 adapted to receive a forefoot. The size and/or the shape of the pocket 530 may be based on the size and/or shape of the stiffening element 510. In some embodiments, the pocket 530 may comprise a finger 534, extending and/or emerging from a base portion of the pocket 530. For example, in some embodiments, the finger 534 of the pocket 530 may extend and/or emerge from the base portion of the pocket such as to extend towards a toe region of the strobel board 520. In some embodiments, the size and/or the shape of the finger 534 may be adapted such that the finger 534 may receive the finger 512 of the stiffening element 510 (see FIG. 5B or 5C).

FIG. 5B shows a configuration where the stiffening element 510 is not (yet) arranged in the pocket 530 of the strobel board 520, according to some embodiments of the present disclosure. In some embodiments, the stiffening element 510 may be inserted into the pocket 530 of the strobel board 520 through the opening 532 of the pocket 530. For example, in some embodiments, the stiffening element 510 may be inserted into the pocket 530 through the opening 532 by moving the stiffening element 510 into the direction {right arrow over (m)}, e.g., by moving the stiffening element 510 towards (and through) the opening 532 of the pocket 530. In some embodiments, the stiffening element may be moved and/or shifted such that the finger 512 of the stiffening element 510 may be received by the finger 534 of the pocket 530.

FIG. 5C shows a stiffening element 510, according to some embodiments of the present disclosure. In some embodiments, the stiffening element 510 may comprise a finger 512 extending and/or emerging from a base portion of the stiffening element 510. In some embodiments, the base portion of the stiffening element 510 may comprise a plurality of apertures 514a, 514b, 514c, 514d and a plurality of ribs 516a, 516b, 516c. In some embodiments, the apertures 514a, 514b, 514c, 514d may be separated by the ribs 516a, 516b, 516c. For example, in some embodiments, the aperture 514b may be separated from the aperture 514c by the rib 516b. In some embodiments, the apertures 514a, 514b, 514c, 514d comprise an elliptical shape. For example, in some embodiments, a semi-major axis of the elliptical shape of the apertures 514a, 514b, 514c, 514d may be essentially parallel to an elongation direction of the strobel board 520. In some embodiments, the apertures 514a, 514b, 514c, 514d of the stiffening element 510 may comprise different shapes and/or sizes. For example, in some embodiments, the aperture 514a may comprise a first shape and/or size and the aperture 514b may comprise a second shape and/or size.