SOLE STRUCTURES FOR FOOTWEAR ITEMS USED FOR CROSS-TRAINING ACTIVITIES

Abstract

The invention relates to a sole construction for a footwear item for cross-training activities, comprising: an outsole component and at least one midsole component, arranged in alignment and parallel to this outsole component, defining the forefoot, midfoot and hindfoot sections along a central longitudinal axis between the distal and proximal ends of this sole construction, each section composed of a flexible elastic polymer material at least in the direction along this central longitudinal axis, and a support component, composed of a virtually non-deformable material and functionally linked between this outsole component and this midsole component in the defined area of ​​the hindfoot section.The support components include a base, designed to be centrally positioned along the posterior part of the user's foot, and inner and outer walls, extending from the inner and outer edges of this base towards the upper end on the inner and outer sides, respectively, and designed to provide horizontal support along the posterior part of the user's foot during use.

Description

[0001] A SOLE STRUCTURE AND ARTICLE OF FOOTWEAR FOR CROSS-TRAINING ACTIVITIES

[0002] The present invention relates to shoe soles, as well as, athletic shoes incorporating such soles. In particular, the invention relates to a shoe sole structure adapted for improved performance and energy efficiency, due to its cross-training ability, for example, to perform in both, lifting and running activities, equally effectively.

[0003] Introduction

[0004] Today, more and more people participate in cross-training activities, such as, for example, CrossFit®-style and functional fitness training Such activities incorporate, inter alia, elements of high-intensity interval training (HI IT), weightlifting (e.g. Olympic weightlifting, powerlifting, strongman), plyometrics, gymnastics, callisthenics, running activities and other exercises. The general aim is to optimise conditioning of the body for strength, endurance and overall fitness, so aerobic activities (e.g. running, swimming, cycling) are typically mixed up with bodyweight exercises (e.g. callisthenics, gymnastics) and weightlifting exercises (e.g. Olympic weightlifting, powerlifting). In a typical workout session or competition, the athlete is required to run, jump, climb, lift and carry weights under time pressure.

[0005] Consequently, many or even most of the cross-training athletes utilise specific gear, such as, for example, lifting straps, protection or support wraps, sleeves, tapes (knees, wrists), lifting belts, harnesses and gloves, but also exercise specific footwear, so as to maximise performance in each of the events or activities. In particular, using the right footwear for a particular exercise can provide significant advantages by providing an optimised grip, support, flexibility or even foot position for a specific exercise. For example, when lifting weights, it is advantageous to use a relatively rigid shoe with a higher heel stack, so as to provide an increased stability and support, while allowing for a greater range of motion (hip rotation I knee flexion) and a more comfortable squat position (improved mechanical angles), as well as, a greater foot lockdown and a secure fit. On the other hand, when running or jumping, suitable cushioning, flexibility and grip will be required to absorb the impact during the initial contact and allow for an optimal foot strike pattern.

[0006] However, when in a timed workout session or a competition, the static and max strength exercises (lifting) combined with the more dynamic movements (running, jumping, climbing) puts the athlete in a dilemma, because currently available footwear may be ok for the dynamic movements, but rather unsuitable for the lifting exercises, and vice versa. Thus, the athlete has to either compromise on the footwear used for all exercises, or lose valuable time changing the footwear for different events, during the session or race. Changing footwear during a race is not really an option, so the athlete is typically forced to use footwear that is not optimized for one or the other, leading to performances below the potentially achievable.

[0007] Accordingly, it is an object of the present invention to provide an improved sole structure, as well as, a shoe adapted to provide optimised support in both, lifting, as well as, running activities.

[0008] Summary of the Invention

[0009] Preferred embodiments of the invention seek to overcome one or more of the above disadvantages of the prior art.

[0010] According to a first aspect of the present invention, there is provided a sole structure for an article of footwear for cross-training activities, comprising: an outsole member and at least one midsole member, arranged in line with and parallel to said outsole member, defining a forefoot-, a midfoot- and a hindfoot sole portion along a longitudinal central axis between a distal end and a proximal end of said sole structure, each one formed from a polymer material that is resiliently flexible at least in a direction along said longitudinal central axis, and a support member, formed from a substantially non-deformable material and operably coupled between said outsole member and said midsole member in a predetermined region of said hindfoot sole portion, comprising: a base portion, configured to centeringly receive a hindfoot portion of a user’s foot, and a medial and lateral side wall portion, extending from a medial and lateral edge of said base portion towards a respective medial and lateral upper end portion, and which is configured to laterally supportingly engage with the hindfoot portion of the user’s foot, during use.

[0011] This provides the advantage of a sole or shoe adapted to provide true cross-training capabilities, i.e. the sole of the shoe is configured to provide lateral support and improved ground stability, as well as, an optimised heel position, while retaining a suitable sole flexibility at anatomically beneficial locations of the foot so as to allow for comfortable running, jumping and climbing. As a result, the user is provided with a shoe with optimised characteristics for static (e.g. lifting), as well as, dynamic (e.g. running, jumping, climbing) movements.

[0012] Advantageously, the predetermined region is substantially defined by a 2D projection of the subtalar joint onto said sole structure, during use. This provides the advantage that the rigidity and lateral stability required for lifting is limited to the hindfoot portion, where most of the support is needed during lifting, and does therefore not interfere with foots plantarflexion when running or jumping.

[0013] Advantageously, said support member is interposed between said outsole member and said midsole member, and configured to intermeshingly couplingly engage with a recessed region of said midsole member shaped complementary to a profile of an upper surface of said support member. The intermeshing coupling between the support member and the midsole member provides for improved stability, during use.

[0014] Advantageously, each one of said medial and lateral side wall portion comprises at least one rib element integrated into a respective outer surface of said medial and lateral side wall portion. This provides the advantage of increased strength of the wall portions, thus, further improving lateral stability.

[0015] Advantageously, said outsole member, said support member and said midsole member are irremovably bonded to each other. Advantageously, said non-deformable material is any one of a substantially incompressible thermoplastic- or a thermosetting polymer material. Preferably, said thermoplastic polymer material is a thermoplastic urethane (TPU).

[0016] Advantageously, the longitudinal extension of said support member is limited to be rearward of the Midtarsal joint of the user’s foot, during use. Preferably, the longitudinal rearward extension of said support member is limited to be forward of a predetermined heel strike zone of said sole structure. This provides the advantage of optimised sole performance for both, dynamic (e.g. running) and static (e.g. lifting) movements, i.e. allowing for normal running or jumping, while still providing lateral- and rigid ground support for lifting.

[0017] Advantageously, each one of said medial and lateral side wall portion is tapered towards respective said medial and lateral upper end portion. This provides the advantage of a support member adapted to centringly align the hindfoot portion of the user, during use.

[0018] Brief Description of the Drawings

[0019] Preferred embodiments of the present invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which:

[0020] Figure 1 shows an illustration of the three anatomical planes, the sagittal plane, the frontal plane and the transverse plane;

[0021] Figure 2 shows (a) a lateral side view and (b) a dorsal top view of the skeletal bone structure of a foot, as well as, (c) a perspective view of a partial foot and ankle joint;

[0022] Figure 3 shows a perspective side-view of an example embodiment of a shoe sole of the present invention;

[0023] Figure 4 shows an exploded perspective view of the shoe sole in Figure 3 (a) from the front and (b) from the rear; Figure 5 shows (a) a bottom view, (b) a medial side-view and (c) a lateral sideview of the shoe sole in Figure 3;

[0024] Figure 6 shows (a) a medial side view, (b) a cross-sectional side-view along A-A, and (c) an enlarged partial cross-sectional rear-view along B-B, and

[0025] Figure 7 shows (a) a rear view, (b) a cross-sectional rear-view along D-D, (c) a cross-sectional rear-view along E-E, and (d) cross-sectional rear-view along F-F of the shoe sole in Figure 3.

[0026] Detailed description of the preferred embodiment(s)

[0027] The exemplified embodiments of this invention will be described in relation to athletic footwear. However, it should be appreciated that, in general, the sole of the present invention will work equally well for any other sole or shoe requiring specifically optimised supporting characteristics for different movements, activities or workouts of the user.

[0028] Certain terminology is used in the following description for convenience only and is not limiting. The words ‘right’, ‘left’, ‘lower’, ‘upper’, ‘front’, ‘rear’, ‘upward’, ‘down’ and ‘downward’ designate directions in the drawings to which reference is made and are with respect to the described component when assembled and mounted. The words ‘inner’, ‘inwardly1and ‘outer’, ‘outwardly’ refer to directions toward and away from, respectively, a designated centreline or a geometric centre of an element being described (e.g. central axis), the particular meaning being readily apparent from the context of the description.

[0029] Further, as used herein, the terms ‘connected1, ‘attached’, ‘coupled’, ‘mounted’ are intended to include direct connections between two members without any other members interposed therebetween, as well as, indirect connections between members in which one or more other members are interposed therebetween. The terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.

[0030] Further, unless otherwise specified, the use of ordinal adjectives, such as, ‘first’, ‘second’, ‘third’ etc. merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner. Like reference numerals are used to depict like features throughout.

[0031] Also, directional adjectives are employed throughout this detailed description corresponding to the illustrated embodiments. For example, the term ‘longitudinal’ refers to a direction extending a length of an article of footwear, that is, extending from a forefoot (i.e. anterior) portion to a heel portion (i.e. posterior). The term ’forward’ is used to refer to the general direction in which the toes of a foot point, and the term ’rearward’ may be used to refer to the opposite direction, i.e. the direction in which the heel of the foot is facing (posterior). A ‘lateral side’ of an article of footwear may be the surface of the footwear that faces away from the other foot, wherein a ‘medial side’ of an article of footwear may be the surface that faces towards the other foot. A ‘central area’ of the sole may be an area between the ‘lateral side’ and the ‘medial side’ of the sole, and / or between the forefoot and the hindfoot (i.e. heel portion). The term ‘horizontal’ refers to any direction substantially parallel with the ground surface. Also, in cases where the sole is planted flat on the ground surface, the horizontal direction may extend along the longitudinal direction of the surface of the sole.

[0032] In addition, the term ‘sole’ can be taken to be either an integral sole, outsole or midsole or combination of the two, or a footbed or orthotic section which can be inserted into a shoe. The term ‘shoe’ is intended to cover a variety of footwear including, but not limited to, athletic shoes, walking boots, football shoes, casual footwear or any other purpose-built footwear. In this particular example, the term ‘shoe’ is directed to athletic footwear.

[0033] For a better understanding of the present invention, a brief revision of the foot’s anatomy is provided.

[0034] Review of foot anatomy

[0035] As illustrated in Figure 1 , by virtue of its unique anatomy, movement of the foot is described using special definitions and reference planes. For example, motion within the sagittal plane 10 is known as dorsiflexion (upward) and plantar flexion (downward), motion within the frontal plane 12 is known as inversion and eversion, and motion within the transverse plane 14 is known as adduction, or internal rotation of the foot when the distal part of the foot moves toward the midline of the leg on its vertical axis, and abduction, or external rotation of the foot when the distal part of the foot moves away from the midline of the leg on its vertical axis. Also, because the mechanical axes of the foot are not perpendicular to any of the cardinal planes, all motion is essentially triplanar, although, in some cases uniaxial.

[0036] Figure 2 shows a simplified illustration of the foot’s skeletal bone structure (a) from a lateral side view, (b) from a dorsal top view and (c) a perspective partial view of the ankle joint and heel portion.

[0037] The ankle joint 16 is a synovial articulation between the inferior aspect of the tibia 18 and fibula 20, and the superior surface of the talus 22. Even though the ankle joint 16 is uniaxial and is often described as a pure plantar flexor and dorsiflexor, its axis is actually oblique, a factor that predominantly results in pronation and supination (i.e. a combination of all three movement). Thus, dorsiflexion of the ankle joint 16 while the foot is fixed causes internal rotation of the tibia 18 and pronation of the foot.

[0038] The subtalar joint 24 (also known as calcaneal joint or talocalcaneal joint) consists of a gliding articulation between the talus 22 and the calcaneus 26. The axis of the subtalar joint 24 runs downward, posteriorly and laterally, at a mean angle of 41 ° (degrees) from the horizontal plane and is 23° rotated from the long axis of the foot, thus, its motion is more equally triplanar than that of the ankle joint 16. Therefore, the axis of the subtalar joint 24 is analogous to an oblique hinge, i.e. when rotation is imparted to the superior aspect of the talus 22, it causes rotation of the calcaneus 26 in the opposite direction. External rotation of the leg produces inversion of the calcaneus 26, and internal rotation causes eversion of the calcaneus 26. The midtarsal joint 32 is a combination of the calcaneocuboid and talonavicular synovial gliding joints (navicular 34, cuboid 34).

[0039] In normal gait the foot strikes the ground at the beginning of the contact phase in a supinated position of approximately 2°. The foot moves through 5.5-6° of pronation (passing through neutral position) to a position of approximately 3.5-4° pronated (allowing the foot to function as a mobile adaptor, adjusting to variances in terrain). At 3.5-4° pronation, the beginning of the mid-stance phase occurs. The foot begins to re-supinate and passes through the neutral position, where the foot begins the propulsive phase continuing in supination through toe-off.

[0040] As a result of the foot supinating during the mid-stance propulsive periods, the foot is converted from a ‘mobile adaptor1(relatively flexible) to a ‘rigid lever1as the midtarsal joint locks in supination. By having the foot function as a ‘rigid lever1(as a result of a locked midtarsal joint) during the time immediately preceding toe-off, the weight of the body is propelled more efficiently. Thus, a running or jumping shoe should be relatively flexible along its longitudinal axis to accommodate for the foot’s natural movement.

[0041] Referring now to Figures 3 and 4, an example embodiment of the shoe sole 100 of the present invention is configured for cross-training activities including weightlifting and dynamic movements, such as, for example, running and jumping.

[0042] In particular, the shoe sole 100 comprises a midsole 104 having a forefoot portion 104a, a midfoot portion 104b and a heel portion 104c along a longitudinal axis 106. The forefoot portion 104a is defined by a substantially transverse groove 108 extending between the medial side 110 and the lateral side 112 on the bottom surface 114 of the midsole 104. Preferably, the transverse groove 108 is curved generally in line with the anterior transverse arch 28 of the metatarsal heads, so as to provide a distinct flex line of the anterior portion of the shoe sole 100.

[0043] A first recessed shape 116 is provided towards the heel portion 104c extending partially down the medial side 110, transversely along the bottom surface 114 and partially up the lateral side 112 of the midsole 104. The first recessed shape 116 is configured to receive a substantially rigid support member 118 that is shaped (and contoured) complementary to the first recessed shape 116 of the midsole 104, i.e. the inner surface contour of the support member 118 matches the surface contour of the first recessed shape 116. The support member 118 may simply be retained by the side surfaces provided by the first recessed shape 116 and / or a suitable adhesive provided between the engaging surfaces of the support member 118 and the first recessed shape 116. The substantially rigid support member 118 comprises a base portion 120 extending transversely across the midsole 104 between the medial side 110 and the lateral side 112 (when in situ) and two side wall portions 122a,b extending upwards (i.e. towards the midsole 104 into the first recessed shape 116) from respective medial and lateral ends of the base portion 120. The opposing side wall portions 122a,b are tapered towards the base portion 120 so as to guidingly centre a heel portion (or hindfoot) of the foot when moved into the shoe. During use, the tapered surfaces of the side wall portions 122a,b ensure that the hindfoot or heel portion is centringly aligned with the shoe sole, as well as, laterally locked into place, i.e. the hindfoot or heel portion is prevented from sliding laterally off the shoe sole (for example during heavy lifting).

[0044] Structurally supporting ribs 124 are integrally formed on the external surface of each one of the two side wall portions 122a, b. In this particular example embodiment, three vertical parallelly arranged ribs 124 are provided on each side wall portion 122a, b, and are shaped so as to maximise lateral stability and structural strength. For example, each one of the ribs 124 is thicker at its base (i.e. at the junction between the base portion 120 and the side wall portion 122a, b) and tapers towards the distal end (i.e. top of the side wall portion 122a, b). Furthermore, each one of the supporting ribs 124 is centrally kinked forward (i.e. towards the anterior portion of the foot). The addition of the integrated ribs 124 provides the advantage of maximised strength of the side wall portions 122a, b while reducing the required material and the weight of the support member 118.

[0045] An outsole 102 is operably coupled with the midsole 104 so as to ‘sandwich’ the support member 118 between the midsole 104 and the outsole 102. In particular, the outsole 102 comprises a first outsole member 102a extending from the heel portion up to the transverse groove 108 of the midsole 104, and a second outsole member 102b extending from the transverse groove 108 of the midsole 104 to the anterior end (i.e. forefoot portion 104a) of the midsole 104.

[0046] The first outsole member 102a comprises laterally opposing wing portions 126a,b extending from respective medial and lateral edge of the first outsole member 102a. The midsole 104 comprises a second recessed shape 128 configured to receive the wing portions 126a,b of the first outsole member 102a, wherein the wing portions 126a,b are attached or affixed to the midsole 104, for example, through a suitable adhesive. Again, the lateral wing portions 126a,b partially overlap with a respective end portion (recessed) of the support member 118 interlockingly fixing the midsole 104, the support member 118 and outsole 102 into a predetermined position, thus, further improving the overall stability of the shoe sole 100.

[0047] The second outsole member 102b is attached (e.g. via a suitable adhesive) to the anterior portion, i.e. the forefoot portion 104a, of the midsole 104. Separation of the first and second outsole member 102a, 102b allows for an improved flexibility of the shoe sole 100, in particular, in the region around the transverse groove 108, which is exposed and unimpeded, so as to, facilitate flexure in the region of the anterior transverse arch (i.e. at the metatarsophalangeal joints of the foot).

[0048] Advantageously, the midsole 104 and outsole 102 are made from a flexible material, such as, for example, a resilient polymer. The midsole material may be polymer foam (e.g. polyurethane, PU, ethyl vinyl acetate, EVA, rubber) or any other suitable polymer or composite with or without graphene based material mixed into the polymer. The outsole material may be an elastomer, such as, PU, TPU, EVA, Polyisoprene or rubber, with or without a graphene base material mixed into the elastomer. Advantageously, the support member 118 is made from a suitably rigid (i.e. a suitable hardness) material, such as a thermoplastic polyurethane (TPU). The material properties of the support member 118 should be such that deformation during use is minimal, while providing optimised strength as well as some flexibility (e.g. Shore D between 70 and 95). Further, the substantially rigid TPU material for the support member 118 may comprise graphene base material.

[0049] During manufacture, the midsole 104, outsole 102 and support member 118 may injection moulded using suitable moulds. The support member 118 is then retainingly received in the first recessed shape 116 (adhesive or bonded) before the first outsole member 102a is adhered or bonded to the midsole 104 and the second recessed shape 128 (wing portions 126a, b) partially wrapping the support member 118 and midsole 104. During use, for example, during a cross training workout or session, the shoe and shoe sole 100 provides a rigid and stable platform for the user’s foot (hindfoot) capable of centring the heel portion onto the sole 100 while providing lateral support during weightlifting, while, at the same time, allowing for flexure of the sole at anatomically critical regions to facilitate natural movement of the foot during running or jumping.

[0050] It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims.

[0051] Reference Numerals:

[0052] 10 saggital plane 122a, b side wall portion

[0053] 12 frontal plane 124 ribs

[0054] 14 transverse plane 126a, b wing portions

[0055] 16 ankle joint 128 second recessed shape

[0056] 18 tibia

[0057] 20 fibula

[0058] 22 talus

[0059] 24 subtalar joint

[0060] 26 calcaneus

[0061] 28 anterior transverse arch

[0062] 32 midtarsal joint

[0063] 34 navicular

[0064] 36 cuboid

[0065] 100 shoe sole

[0066] 102 outsole

[0067] 102a first outsole member

[0068] 102b second outsole member

[0069] 104 midsole

[0070] 104a forefoot portion

[0071] 104b midfoot portion

[0072] 104c heel portion

[0073] 106 longitudinal axis

[0074] 108 transverse groove

[0075] 110 medial side

[0076] 112 lateral side

[0077] 114 bottom surface midsole

[0078] 116 first recessed shape

[0079] 118 support member

[0080] 120 base portion

Claims

CLAIMS1 . A sole structure for an article of footwear for cross-training activities, comprising: an outsole member and at least one midsole member, arranged in line with and parallel to said outsole member, defining a forefoot-, a midfoot- and a hindfoot sole portion along a longitudinal central axis between a distal end and a proximal end of said sole structure, each one formed from a polymer material resiliently flexible at least in a direction along said longitudinal central axis, and a support member, formed from a substantially non-deformable material and operably coupled between said outsole member and said midsole member in a predetermined region of said hindfoot sole portion, comprising: a base portion, configured to centeringly receive a hindfoot portion of a user’s foot, and a medial and lateral side wall portion, extending from a medial and lateral edge of said base portion towards a respective medial and lateral upper end portion, and which is configured to laterally supportingly engage with the hindfoot portion of the user’s foot, during use.

2. A sole structure according to claim 1 , wherein said predetermined region is substantially defined by a 2D projection of the subtalar joint onto said sole structure, during use.

3. A sole structure according to any one of the preceding claims, wherein said support member is interposed between said outsole member and said midsole member, and configured to intermeshingly couplingly engage with a recessed region of said midsole member shaped complementary to a profile of an upper surface of said support member.

4. A sole structure according to any one of the preceding claims, wherein each one of said medial and lateral side wall portion comprises at least one rib element integrated into a respective outer surface of said medial and lateral side wall portion.

5. A sole structure according to any one of the preceding claims, wherein said outsole member, said support member and said midsole member are irremovably bonded to each other.

6. A sole structure according to any one of the preceding claims, wherein said non- deformable material is any one of a substantially incompressible thermoplastic- or a thermosetting polymer material.

7. A sole structure according to claim 6, wherein said thermoplastic polymer material is a thermoplastic urethane (TPU).

8. A sole structure according to any one of the preceding claims, wherein the longitudinal extension of said support member is limited to be rearward of the Midtarsal joint of the user’s foot, during use.

9. A sole structure according to claim 8, wherein longitudinal rearward extension of said support member is limited to be forward of a predetermined heel strike zone of said sole structure.

10. A sole structure according to any one of the preceding claims, wherein each one of said medial and lateral side wall portion is tapered towards respective said medial and lateral upper end portion.

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