NO20240295A1

NO20240295A1 - Flexible sole with protrusions for improved gait stability and balance

Info

Publication number: NO20240295A1
Application number: NO20240295A
Authority: NO
Inventors: Evi Petersen
Original assignee: Univ I Soeroest Norge
Priority date: 2024-03-26
Filing date: 2024-03-26
Publication date: 2025-09-29
Also published as: WO2025202334A1

Description

FLEXIBLE SOLE WITH PROTRUSIONS FOR IMPROVED GAIT STABILITY AND

BALANCE.

FIELD OF INVENTION

[0001] Aspects of the present disclosure relate to a sole for a shoe. Specifically, but not exclusively, aspects of the present disclosure are directed to a sole with protrusions. Specially, but not exclusively, aspects of the present disclosure are directed to a sole with protrusions for improving gait stability or balance.

BACKGROUND

[0002] Fall incidents are among the costliest factors for the health sector, posing a threat to both the lives and quality of life of a large and aging segment of the population. Balance, and particularly gait stability, are key indicators of the risk of falling. To reduce the risk of falls in individuals with balance impairments, both active training and appropriate footwear are crucial.

[0003] To support an improvement in balance and gait stability, various types of footwear and assistive devices have been developed. These inventions primarily aim to reduce the immediate risk of falling by offering external support to the foot. For example, often footwear is designed to absorb ground reactive forces, thereby cushioning the impact on the foot. Rocker-soled shoes are one such example. However, gait research indicates that these short-term solutions decrease balance and gait stability over the long term due to missing activation of the active foot core system.

[0004] Other interventions that target the soles of the feet have also been proposed to improve balance, including insoles, textured footbeds (e.g. US 2017/0303635 A1), acupressure socks (e.g. WO2005/018350), or other foot garments (e.g. US 2018/0028116 A1). These are designed to induce both short-term and long-term changes in balance parameters. While these inventions often take the anatomical features of the foot into account, they do not consider the biomechanical characteristics essential for enhancing balance and gait parameters. Thus, the effectiveness of these interventions is determined by the surface of the sole of the footwear with which they are used, due to the fact that the surface-facing sole mediates ground reactive forces.

[0005] While there are shoes with a focus on thin soles for impacting gait, as shown by Petersen et al. “Walking barefoot vs. with minimalist footwear – influence on gait in younger and older adults”, these are directed towards imitating barefoot walking and hence can result in no or limited improvement to balance and gait stability, especially among mobility-impaired wearers. As an improvement to the thin sole concept, various sole designs have been disclosed (e.g. US2015313310A1, CN201919811U, or DE102014001951A1), but none have been able to successfully direct ground reactive forces or utilise necessary biomechanical characteristics for improving gait stability and balance in both short and long terms.

SUMMARY OF INVENTION

[0006] According to an aspect of the present disclosure, there is provided a sole for improving gait stability or balance. The sole comprises a surface facing side comprising a plurality of protrusions aligned with anatomy of a foot. Each protrusion of the plurality of protrusions comprises a height between 3 mm and 10 mm protruding outwards from the surface facing side. Each protrusion comprises a separation from a neighbouring protrusion of between 10 and 20 mm, measured from an apex of the protrusion and an apex of the neighbouring protrusion. Each protrusion further comprises a width determined by a position upon the sole, wherein the width is proportional to the size of the sole.

[0007] According to a further aspect of the present disclosure, there is provided a stimulated functional foot active system for dynamic support based on foot position while standing and walking, the stimulated functional foot active system comprising the sole of any preceding claim, wherein the sole is configured to facilitate higher recruitment of the muscles when weight load is applied to the functional foot active system.

[0008] According to an additional aspect of the present disclosure, there is provided a shoe comprising an upper material and the sole described above. The upper material comprises a stretch knit fabric attached to the sole, wherein tension within the upper material alters as the sole changes in shape during the gait cycle. The upper material further comprises a reinforcing element around an Achilles tendon or ankle joint of the foot to enhance proprioception support.

[0009] Beneficially, the sole leverages biomechanical principles for optimal force distribution, tailored to the anatomy of the foot, and adapted to the gait cycle. Therefore, the sole is configured such that it assists in both short-term and long-term balance and gait stability enhancement and maintenance, substantially reducing the risk of falling. The sole is further beneficial for individuals facing gait instability or those who wish to proactively prevent balance impairments, such as older adults and some clinical populations experiencing imbalance because of their condition. Additionally, modifications accommodate individuals who have difficulty bending down to reach their footwear or other mobility impairments.

BRIEF DESCRIPTION OF DRAWINGS

[0010] Embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:

[0011] Figure 1 illustrates a diagram of a sole;

[0012] Figures 2A and 2B illustrate a diagram of a sole comprising a plurality of protrusions;

[0013] Figure 3 illustrates a diagram of a sole for a shoe comprising a plurality of protrusions at different magnifications;

[0014] Figure 4 illustrates a diagram of a magnified plurality of protrusions from a side-angle view;

[0015] Figure 5 illustrates a diagram of a sole comprising an upper facing side;

[0016] Figure 6 illustrates a diagram of a shoe comprising a sole; and

[0017] Figure 7 illustrates a flexible sole.

DETAILED DESCRIPTION

[0018] Embodiments of the present disclosure will now be described with reference to the attached figures. It is to be noted that the following description is merely used for enabling the skilled person to understand the present disclosure, without any intention to limit the applicability of the present disclosure to other embodiments which could be readily understood and/or envisaged by the reader. In particular, whilst the present disclosure is primarily directed to a flexible sole comprising a plurality of protrusions, the skilled person will appreciate that the methods and systems described herein are applicable to any shoe or gait-enhancing system, such as exercise/physio equipment including cross-trainers, treadmills, or step-machines, where protrusions described herein can impact the foot, resulting in improved gait stability and balance.

[0019] Figures 1-7 illustrate soles and footwear for improving gait stability and balance in situations of both short-term and long-term usage. The foot represents one of the body's most complex biomechanical systems, yet its potential has seldom been sustainably harnessed in the design of footwear. The embodiments disclosed herein, grounded in biomechanical gait research, are optionally directed towards a sole, or footwear comprising a sole, based at least partially on the biomechanical systems associated with the foot, walking, running, and other anatomy and processes required for movement/motion. The sole and associated footwear of Figures 1-7 are based on a minimalist footwear approach, preferably comprising a thin, flexible, and zero-drop sole with a wide-cut forefoot area and no arch support, as opposed to a cushioned traditional footbed. The development of the sole is uniquely informed by biomechanical research aligning gait cycle and proprioception principles. The embodiments disclosed herein optionally actively harnesses the ground reactive forces that arise from contact with the surface, which create micro-disruptions to stimulate a foot's core system and the proprioceptors in the foot and ankle region. As a result, the sole or associated footwear contributes to both short-term and long-term improvements in gait stability. Figures 1-7 are further directed towards a functional foot active subsystem that offers local dynamic support, can sense foot position, provides postural control while standing and walking, and facilitates higher recruitment of the muscles when weight load is applied.

[0020] Figure 1 illustrates a diagram of a sole for a shoe. Specifically, Figure 1 shows a diagram of a sole 100 according to example embodiments of the present disclosure. Specifically, but not exclusively, Figure 1 shows an embodiment of sole 100 for improving gait stability and balance.

[0021] Sole 100 comprises a wide-cut forefoot area 102, a rearfoot area 104, and a midfoot area 106. The surface-facing side of the sole 100, surface facing side 108, comprises a plurality of protrusions aligned with the anatomy of the foot. The plurality of protrusions applies the principles of biomechanical force distribution principles to create micro-disturbances, which stimulate the active foot structure and activate proprioception throughout the entire foot and ankle region. This alignment facilitates the distribution of force across the wide-cut forefoot area 102, the rearfoot area 104, and the midfoot area 106 during both stance and the gait cycle.

[0022] The sole 100 comprises a wide-cut forefoot area 102 to provide space to a wide forefoot area of the foot and/or provide space for hallux valgus deformations. Both are more often found in an older population and related to age-related degenerative aspects of the foot anatomy, and hallux valgus is associated with a higher risk of falling in older adults. The wide-cut forefoot area 102 increases the contact surface area, allowing any force pressures during walking and standing to be distributed more evenly across the forefoot. Even distribution of force helps lower the risk of falls during activities and across a variety of settings at least due to a steadier foundation for balance and improved sensory feedback from the receptors in the skin of the foot sole. Therefore, improved sensory feedback from the wide-cut forefoot area 102 is especially beneficial to people suffering from conditions such as peripheral neuropathy. Furthermore, the wide cut of the wide-cut forefoot area 102 helps avoid pain related to pressure point related to wide forefoot structures and existing hallux valgus. The wide cut enables the range of motion in the metatarsophalangeal joint, contributing to stopping or slowing down the development of hallux valgus.

[0023] For efficient distribution of the ground reactive forces into different regions of the foot system, the sole comprises any of the following characteristics: the sole is flat, thin, and/or flexible; the sole is without a footbed, resulting in alteration of the kinematic gait parameters in different environmental conditions compared to normal cushioning shoes or barefoot walking; and/or the shape and arrangement of protrusions allow for the distribution of force in anterior, posterior, lateral, and medial directions, resulting in creation of micro-perturbations for the equilibrium, activating the foot muscles and proprioception. For example, the plurality of protrusions is aligned with the anatomy of the foot such that force is distributed along force distribution line 110 and/or force distribution line 112.

[0024] Optionally, the force distribution line 110 is associated with a boundary between the wide-cut forefoot are 102 and the midfoot area 106. Further optionally, the force distribution line 112 is associated with a boundary between the midfoot area 106 and the rearfoot area 104. However, the skilled person will understand that: the wide-cut forefoot area 102 is an area of the sole 100 associated with anatomy of the forefoot area of a foot, e.g. the ball of the foot at the toes; the rearfoot area 104 is an area of the sole 100 associated with anatomy of the rearfoot area of a foot, e.g. the heel; and the midfoot area 106 is an area of the sole 100 associated with anatomy of the midfoot area of a foot, e.g. the arch. Therefore, the wide-cut forefoot area 102, rearfoot area 104 and midfoot area 106 are not limited by boundaries such as force distribution line 110 or force distribution line 112, and optionally overlap. For example, force distribution line 110 and/or force distribution line 112 are within the midfoot area 106.

[0025] Sole 100 improves gait stability and/or balance by comprises surface facing side 108, which comprises a plurality of protrusions aligned with anatomy of a foot. Each protrusion of the plurality of protrusions comprises a height between 3 mm and 10 mm protruding outwards from the surface facing side, e.g. between 3 mm and 7 mm or between 5 mm and 10 mm. Preferably, the height of each protrusion, or the majority of protrusions, is uniform, such as a uniform height of 4 mm.

[0026] Each protrusion further comprises a separation 114 from a neighbouring protrusion of between 10 and 20 mm, measured from an apex of the protrusion and an apex of the neighbouring protrusion. For example, the apex is the tallest point of the protrusion and/or a central point of the protrusion, which is preferably also used to determine the heigh of each protrusion. The width of each protrusion is determined by a position upon the sole, and is proportional to the size of the sole. For example, the plurality of protrusions comprises at least four protrusions having four different widths between 5 mm and 30 mm. E.g., a first width of 10 mm, a second width of 11 mm, a third width of 14 mm, and a fourth width of 23 mm. Preferably, the plurality of protrusions comprises one or more spherical caps, e.g. each protrusion is a spherical cap. Therefore, the apex is the central apex and the tallest point of the spherical cap, and the width is the diameter of the spherical cap, measured from the diameter across the widest point of interception between the spherical cap and the surface facing side 108, or measured as the diameter of a figurative sphere forming the spherical cap, as shown in relation to Figure 4 below.

[0027] Alignment of the plurality of protrusions is based on proprioception of the foot and facilitates a distribution of force during a stational position or during a gait cycle. Preferably, the distribution of force is configured to result in perturbations for an equilibrium, activating proprioception and muscles of the foot. A position of each protrusion is therefore calculated based on biomechanical principles active during the gait cycle.

[0028] Optionally, the sole 100 comprises a flexible material up to 2 cm thick. For example, the flexible material is any of: a polyvinyl chloride compound, a soft polyvinyl compound with a shore value of between 30 and 60, a soft polyvinyl compound with a shore value of between 35 and 55, a soft polyvinyl compound with a shore value of between 34 and 46, Ethylene Vinyl Acetate, natural rubber, or Algae Biomass.

[0029] Figures 2A and 2B illustrate diagrams of soles for a shoe. Specifically, but not exclusively, Figures 2A and 2B show alternative embodiments of sole 100 for improving gait stability and balance based on a plurality of protrusions 200.

[0030] Figure 2A shows surface facing side 108 comprising a plurality of protrusions 200, where the plurality of protrusions 200 are spherical caps. Figure 2B shows surface facing side 108 comprising a plurality of protrusions 200, where the plurality of protrusions 200 are alternative shapes. The plurality of protrusions 200 are not limited to the shapes depicted in Figures 2A and 2B, and are optionally any shape capable of being placed beneath or otherwise integrated with sole 100, e.g. to align with the anatomical structure of the foot's three main areas and the biomechanical principles active during gait based on biomechanical calculation.

[0031] Foot core stability is essential for the effective biomechanical function of the musculoskeletal system of the lower extremity. The foot core system of the foot is comprised of the plantar intrinsic muscles, which are functionally connected to both foot arches. These muscles offer rapid sensory feedback in response to alterations in foot positioning. When changes in the ankle's muscle length, joint position or movement velocity occur, the central nervous system (CNS) uses this information to plan a movement and execute gait (proprioception pathway). Additionally, ageing negatively affects muscle spindles and their neural pathways leading to less sensitivity and less acuity. However, these proprioceptive pathways and muscles respond well to stimulation and their sensitivity to deformation can be trained. Beneficially, the plurality of protrusions 200 is positioned to generate such stimulation to improve sensitivity to deformation.

[0032] The plurality of protrusions 200 are aligned based on any of: biomechanical mechanisms, anatomical mechanisms, proprioception-related mechanisms or a combination thereof. For example, positioning of the plurality of protrusions 200 on the sole is based on the biomechanics of the foot during gait, the principles of foot core stability, and/or the consideration of anatomical degenerative processes regarding the foot and ankle region.

[0033] The space between the plurality of protrusions 200 allows the sole to distribute forces across its entirety, offering a degree of flexibility to change form. The adaptability enables the sole to conform to various surface structures, providing a range of ground reaction forces that are distributed with high frequency. Beneficially, the forces result in micro-training effects to the active core system of the feet. Optionally, the space is 10mm – 20mm measured between the centre of a protrusion of the plurality of protrusions and the centre of a neighbouring protrusion of the plurality of protrusions, e.g. the top of spherical caps.

[0034] Optionally, due to the zero-drop design of this footwear, the plurality of protrusions 200 integrated into the sole maintain a uniform height of between 3-10 mm, e.g. 4 mm or 5 mm. Further optionally, the plurality of protrusions 200 vary in diameter. For example, sizes of the plurality of protrusions 200 are proportionally adjusted for different footwear sizes, such that larger shoe sizes have proportionately larger and/or more protrusions. In another example, the sizes of the plurality of protrusions 200 depend on the position of a protrusion relative to which area of the sole the protrusion is placed and/or the anatomy of the foot.

[0035] According to one embodiment, there are at least four different sizes of protrusions within the plurality of protrusions 200: a first protrusion 202, a second protrusion 204, a third protrusion 206, and a fourth protrusion 208. For example, for an EU size 40 sole where the plurality of protrusions 206 are spherical caps or otherwise circular: the first protrusion 202 has a diameter of 10 mm; the second protrusion 204 has a diameter of 11.29 mm; the third protrusion 206 has a diameter of 14.24 mm; and the fourth protrusion 208 has a diameter of 23.14 mm.

[0036] Additionally, or alternatively, the size and arrangement of the plurality of protrusions 200 are different in the three main areas of the foot to be aligned with the biomechanics of and degenerative changes in the foot anatomy associated with an older age group or people with neuro-muscular impairment related to the foot and ankle region.

[0037] For example, the rearfoot area 104 comprises at least two different sized protrusions. Each phase of the gait cycle requires the different structures to stiffen or become mobile for proper energy storage and release. The rearfoot area 104 is particularly involved in the first part of a gait cycle, also known as the contact period. Due to its arched structure, weight-bearing on the foot while standing primarily takes place in two key areas: the heel area, supported by the calcaneus bone, and the forefoot area, supported by the heads of the metatarsal bones. With an increase in age, the fat pad provides less cushioning, which can be specifically painful in the calcaneus bone area. Thus, a combination of smaller (e.g. second protrusion 204) and bigger (e.g. fourth protrusion 208) protrusions activate muscle while simultaneously supporting the less cushioning passive structure in the calcaneus bone region of the foot. Optionally, there are at least 5 protrusions in the rearfoot area 104, e.g. over 10 protrusions, and/or the rearfoot area 104 is associated with enough protrusions to cover the majority of the rearfoot area 104.

[0038] In another example, the midfoot area 106 comprises at least three different sized protrusions. If the four intrinsic layers of the foot fail to function correctly, this can lead to undesirable changes in the arch's shape. Such changes can cause several issues, including plantar fasciitis, dysfunction of the posterior tibial tendon, medial tibial stress syndrome, and persistent pain in the lower leg. Due to age-related degenerative processes, muscles tissue in this area thins out, short plantar flexor muscles weaken, which often results in curled toes. Often, the muscles associated with midfoot area 106 need stimulation to strengthen again. Therefore, an increased structural complexity in positioning of protrusions in the midfoot area 106 is beneficial, e.g. where support for the passive arch structure is balanced with avoiding structural overstimulation. A combination of three or more different sizes of the plurality of protrusions (e.g. first protrusion 202, second protrusion 204, third protrusion 206, and optionally fourth protrusion 208) helps to distribute the biomechanical forces aligned with the anatomy of the muscles and tissue stretch directions, while still allowing the different structures to stiffen or become mobile for proper energy storage and release. Optionally, there are at least 5 protrusions in the midfoot area 106, e.g. over 15 protrusions, and/or the midfoot area 106 is associated with enough protrusions to cover the majority of the midfoot area 106.

[0039] In a further example, the wide-cut forefoot area 102 comprises many small protrusions. The front part of the human foot's sole, along with its outer edges, has a higher density of skinbased mechanoreceptors. These receptors are particularly responsive to pressure in general, and pressure variation in particular. Beneficially, a higher number of smaller protrusions (e.g. first protrusion 202) on the wide-cut forefoot area 102 allow the pressure resulting from the surface to be distributed more evenly across the forefoot, leading to high stimulation of plantar mechanoreceptors located in the regions that are not normally stimulated in a conventional shoe with a dampened or flat sole. A high number of small protrusions therefore provides the central nervous system with a higher load of sensory information to elaborate on descending motor strategies (i.e., improved muscle activity and/or gait stability), resulting in better motor control and thus better short and long-term dynamic gait stability. Furthermore, a combination of the wide cut of the wide-cut forefoot area 102 and the micro-balance disturbances created through arrangement of the plurality of protrusions on the surface of the sole are likely to trigger toe muscles activity. Optionally, there are at least 10 protrusions in the wide-cut forefoot area 102, e.g. over 30 spherical caps, and/or the wide-cut forefoot area 102 is associated with enough protrusions to cover the majority of the wide-cut forefoot area 102.

[0040] Figure 3 illustrates a diagram of a sole for a shoe. Specifically, but not exclusively, Figure 3 shows an embodiment of a wide-cut forefoot area 102 of sole 100 comprising a plurality of protrusions 200 optionally in the shape of spherical caps.

[0041] As described above in relation to Figure 2, the wide-cut forefoot area 102 preferably comprises a high density of smaller protrusions, e.g. multiple first protrusions 202. A section of the wide-cut forefoot area 102 is shown in wide-cut forefoot area 102-A, where the first protrusions 202 are shown protruding from the surface facing side 108 of sole 100. Wide-cut forefoot area 102-B is a section of wide-cut forefoot area 102-A, shown at a magnified and side-facing angle. Preferably, each first protrusion 202 is separate from neighbouring first protrusions such that there is a space between each first protrusion 202. For example, a space of 10 mm to 20 mm for an EU size 40 measured between the top/apex of the spherical caps allows the sole 100 to efficiently distribute forces across wide-cut forefoot area 102, while simultaneously allows for flexibility to change form, e.g. as shown in Figure 7, below.

[0042] According one embodiment, wide-cut forefoot area 102 comprises a plurality of spherical caps of uniform or near-uniform size, e.g. a plurality of first protrusions 202 shown in wide-cut forefoot area 102-A, integrated into the sole 100 as to protrude from the surface facing side 108, as shown in wide-cut forefoot area 102-B.

[0043] Surface facing side 108 is connected at sole edge 302 to a shoe material 304. Optionally, sole 100 comprises shoe material 304 to increase foot support. Shoe material 304 comprises the same material as sole 100 or a different material, such as a fabric, e.g. a flexible knitted or elastic fabric. Further details of how the sole 100 is integrated or otherwise used within a show or active foot system are shown in relation to Figure 6, below.

[0044] Figure 4 illustrates a side-facing diagram of a sole for a show. Specifically, Figure 4 shows alternative embodiments of a wide-cut forefoot area 102 of sole 100 comprising a surface facing side 108 with first protrusions 202.

[0045] Wide-cut forefoot area 102-C shows the first protrusions 202 protruding from the surface facing side 108 of sole 100. Here, the first protrusions 202 have different heights and a separation 114. Wide-cut forefoot area 102-D shows the first protrusions 202 protruding from the surface facing side 108 of sole 100. Here, the first protrusions 202 have uniform heights and a uniform separation 114.

[0046] Spherical cap protrusion 400 is an example first protrusion 202, where the height 402 is measured between the apex of spherical cap protrusion 400 and the surface facing side 108. Additionally, the width 404 is measured as the smallest point, widest point, or a mid-point of the smallest and widest points, of the spherical cap protrusion 402 where it protrudes from the surface facing side 108. The skilled person will understand that spherical cap protrusion 400 may be an alternative shape to those depicted in Figure 4.

[0047] Alternatively, the height 402 is measured between the apex of the spherical cap and the centre of sphere 406 comprising spherical cap protrusion 400, and/or the width 404 of spherical cap protrusion 400 is measured as the diameter of sphere 406. The sphere 406 is optionally a physical sphere embedded into sole 100, optionally a figurative or theoretical sphere calculated based on the shape of spherical cap protrusion 400, or is an alternative shape comprising a width or diameter, such as a hemisphere embedded into sole 100.

[0048] Figure 5 illustrates a diagram of a sole for a shoe. Specifically, but not exclusively, Figure 5 shows an embodiment of a foot facing side 500 of sole 100 comprising a textured upper sole 502.

[0049] The textured upper sole 502 is configured to be in contact with the foot, preferably without socks lining the foot, additional inserted insoles over the sole 100, or other boundaries between the foot and the textured upper sole 502, to aid in stimulation of the foot enhanced or otherwise generated by the textured upper sole 502.

[0050] The textured upper sole is especially beneficial for individuals at high risk of falling due to one or more protrusions, (e.g. any of protrusion 504, protrusion 506, protrusion 508, protrusion 510, and/or protrusion 512) positioned to stimulate the foot while simultaneously increasing stability. Beneficially, as textured insoles offer tactile stimulation, the textured upper sole 502 enhances short-term dynamic gait balance. This stabilizing feature aids the foot's core system in more effectively managing micro-perturbations caused by the sole's surface-facing side, contributing to improved short-term dynamic balance.

[0051] Optionally, the textured upper sole 502 is configured with a texture pattern, e.g. comprising 2 mm-deep protrusions such as spherical caps (e.g. protrusions 506). Alternatively, the depth/height of protrusions is based on the size of the sole 100, the anatomy of the foot, or is otherwise associated with the gait, balance, or mobility capabilities of a wearer/user. The textured pattern optionally comprises protrusions with a high density, e.g. a plurality of protrusions covers the majority of the textured upper sole 502, or protrusions with a low density, e.g. the plurality of protrusions does not cover the majority of the textured upper sole 502. A high-density coverage results in improved overall stimulation of the foot, and hence is associated with greater improvement to gair stability and balance, while a low-density coverage results in targeted stimulation, for targeted (e.g. user-specific) gait and/or balance improvement.

[0052] For example, the textured upper sole 502 comprises a plurality of protrusions placed with a high density. According to one embodiment (e.g. for foot size EU 40), one or more protrusions have a diameter/width of 3 mm, and the edge of the protrusion is spaced 2 mm apart from the edge of a neighbouring protrusion. According to an alternative embodiment (e.g. for foot size larger than EU 40), each protrusion has a diameter/width larger than 3mm, and the edge of each protrusion is spaced 2 mm or more apart from the edge of a neighbouring protrusion. According to a further alternative embodiment (e.g. for foot size smaller than EU 40), one or more protrusions have a diameter/width smaller than 3mm, and the edge of each protrusion is spaced 2 mm or more apart from the edge of a neighbouring protrusion.

[0053] Figure 6 illustrates a diagram of a shoe comprising a sole and an upper part. Specifically, but not exclusively, Figure 6 shows an embodiment of shoe 600 comprising sole 100 and upper part 602.

[0054] Upper part 602 provides immediate support for balance by activating the skin's mechanoreceptors due to the constant variation in pressure force distribution. Additionally, or alternatively, upper part 602 initiates the training of sensory input interpretation, enhancing long-term proprioception and reducing the risk of falls.

[0055] The upper part 602 is configured to provide proprioceptive activation via force distribution on sensory skin receptors. The upper part 602 comprises a material that is flexible and stretchable, e.g. crafted from stretch knit fabric of any suitable composition. The upper part 602 is attached to the sole 100, e.g. glued or stitched. As the shape of sole 100 dynamically changes with each step during walking, it alters the tension within the upper part 602, and therefore the stretch material. The variation in tension generates subtle pressure differences across the upper foot, e.g. across the skin, including the toe area 604, the rear area 606, and/or side areas 608 of the foot, due to the force distribution principles.

[0056] To enhance support, especially around the Achilles tendon and ankle joint, the upper part 602 is reinforced with a reinforcing element. For example, the reinforcing element is a slightly thicker fabric and/or adjusted knitting pattern. The shifting force pressure stimulates the skin's mechanoreceptors, which are sensory receptors responsive to touch, vibration, pressure, and skin stretching. These receptors, along with musculoskeletal receptors like the muscle spindle and Golgi tendon organ, play a vital role in body positioning and muscle control.

[0057] Optionally, upper part 602 further comprises a high strap 610. The high strap 610 around the heel at the back of the footwear allows for shoe 600 to easily slip on and off when desired by the wearer without allowing shoe 600 to be displaced from the foot during usage. As minimalist footwear or footwear with flexible with soles are most often difficult to put on, high strap 610 provides a uniquely user-friendly design to addresses this issue. Specifically, it is possible to put the footwear easy and quick on and take it off without the necessity of having to use upper body strength, or needing flexibility to bend over, or having a functional fine motoric in the fingers. As people age, they often face difficulties with donning (putting on) and doffing (taking off) shoes, primarily due to natural degenerative processes that result in less flexible tissues, decreased muscle strength, and compromised neuromuscular coordination). Similarly, individuals with neuromuscular impairments and movement disorders, such as Parkinson’s disease), frequently encounter these challenges. Therefore, there is a need for innovative footwear designs featuring simple and efficient closure systems to maintain autonomy among these populations. Shoe 600, and specifically the high strap 610, addresses such issues that the above-mentioned populations struggle with, e.g. those who are mobility impaired.

[0058] Preferably, the high strap 610 comprises a hook-opening mechanism, enabling it to be pulled or pushed back over the heel relatively effortlessly, e.g. using fingers, the other foot, or a device such as a shoehorn. Additionally, or alternatively, the heel area 606 is configured to bend back easily (bending direction 612), optionally facilitated by additional elastic strips 614 located on both sides between the midfoot area 608 and rearfoot area 606. These elastic strips specifically allow the rear heel area of the footwear to bend back. When the pressure on the back strap is released, the elastic strips immediately return to their original position, ensuring the foot remains securely within the footwear during use, preventing it from sliding out.

[0059] Further optionally, the opening of the shoe 600 is reinforced by a thin, flexible bow element 616 positioned in the midfoot area, spanning the arch. This bow element 616 helps the upper part 602 maintain its shape around the opening despite the softness of the materials comprising the upper part 602, further aiding in the slip-on functionality.

[0060] Optionally, shoe 600 is worn with or without socks, and use of additional insoles is also optional. Additionally, shoe 600 is suitable for indoor use and suitable for outdoors. Preferably, choice of material, such as stretch knit fabric, results in shoe 600 being lightweight and/or compact, e.g. a pair will weigh less than 400 grams (EU size 40).

[0061] Figure 7 illustrates a sole bent into a spiral. Specifically, but not exclusively, Figure 7 shows an embodiment of sole 100 rolled into a spiral position.

[0062] According to one embodiment, sole 100 comprises a material that is soft, flexible, durable, and/or protective/resistant to small stones, broken glass, heat, cold. For example, sole 100 comprises a soft polyvinyl chloride (PVC) compound with a shore value of 35-55, Ethylene Vinyl Acetate (EVA), natural rubber, Algae Biomass, or another suitable material that balances flexibility with durability. Beneficially, this allows sole 100 to alter with the environment, e.g. stretch and adjust based on the ground beneath sole 100, and stimulate the foot accordingly, improving gait stability and balance for at least the reasonings provided above. Preferably, the material is soft and flexible enough to be malformed, e.g. at least partially rolled as shown in Figure 7, and elastic enough to return to a mostly flat position, e.g. as shown in Figure 6.

[0063] Preferably, the thickness 700 of sole 100 is below 2 cm. For example, the thickness 700 of sole 100 not including the height of the plurality of protrusions 200 is 1.5 cm.

[0064] Regarding the above disclosure, references to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the context. Additionally, grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Thus, the term “or” should generally be understood to mean “and/or” and so forth. The use of any and all examples, or exemplary language (“e.g.,” “such as,” “including,” or the like) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the embodiments or the claims.

[0065] The following statements encompass example embodiments of the systems and method described herein, and do not define the scope of the invention, which is instead defined in the appended claims.

Statements of invention:

1. A sole for improving gait stability or balance, the sole comprising:

a surface facing side comprising a plurality of protrusions aligned with anatomy of a foot, wherein each protrusion of the plurality of protrusions comprises:

a height between 3 mm and 10 mm protruding outwards from the surface facing side;

a separation from a neighbouring protrusion of between 10 mm and 20 mm, measured from an apex of the protrusion and an apex of the neighbouring protrusion; and

a width determined by a position upon the sole, and wherein the width is proportional to the size of the sole.

2. The sole of statement 1, wherein the sole comprises a flexible material.

3. The sole of statement 2, wherein the flexible material is resilient against small tones, broken class, heat or cold.

4. The sole of statement 1 or 2, wherein the flexible material is any of: a polyvinyl chloride compound, a soft polyvinyl compound with a shore value of between 30 and 60, Ethylene Vinyl Acetate, natural rubber, or Algae Biomass.

5. The sole of any preceding statement, wherein the plurality of protrusions comprises one or more spherical caps.

6. The sole of any preceding statement, wherein alignment of the plurality of protrusions facilitates a distribution of force during a stational position or during a gait cycle.

7. The sole of statement 6, wherein alignment of the plurality of protrusions is based on proprioception activation of the foot.

8. The sole of statement 6 or 7, wherein a position of each protrusion is calculated based on biomechanical principles active during the gait cycle.

9. The sole of any of statements 6-8, wherein the distribution of force is in anterior, posterior, lateral, and medial directions.

10. The sole of any of statements 6-9, wherein the distribution of force is configured to result in perturbations for an equilibrium, activating proprioception and muscles of the foot.

11. The sole of any preceding statement, wherein the sole comprises a wide-cut forefoot area, a rearfoot area, and a midfoot area.

12. The sole of statement 11, wherein the width of each protrusion of the plurality of protrusions is determined by which area of the sole the protrusion is placed.

13. The sole of statement 12, wherein the rearfoot area comprises a combination of one or more protrusions having a first width and one or more protrusions having a second width.

14. The sole of any of statement 12 or 13, wherein the midfoot area comprises a combination of four or more protrusions having four different widths.

15. The sole of any of statements 12-14, wherein one or more protrusions in the wide-cut forefoot area are smaller in width than one or more protrusions in the rearfoot area or the midfoot area.

16. The sole of any preceding statement further comprising a foot facing side configured to be in contact with the foot, wherein the foot facing side comprises a textured upper sole.

17. The sole of statement 16, wherein the textured upper sole comprises one or more 2 mmdeep protrusions, each with a width of 3 mm and spaced 2 mm apart from each other's edges.

18. The sole of any preceding statement, wherein the sole is configured without an arch support or a footbed.

19. The sole of any preceding statement, wherein the sole is up to 2 cm thick.

20. The sole of any preceding statement, wherein the heigh of each protrusion is uniform.

21. The sole of any preceding statement, wherein the heigh of each protrusion is between 5 mm and 10 mm protruding outwards from the surface facing side.

22. The sole of any preceding statement, wherein the heigh of each protrusion is between 3 mm and 7 mm protruding outwards from the surface facing side.

23. A functional foot active system for dynamic support based on foot position while standing and walking, the functional foot active system comprising the sole of any preceding statement, wherein the sole is configured to facilitate higher recruitment of the muscles when weight load is applied to the functional foot active system.

24. A shoe comprising an upper material and the sole of any of statements 1-22, the upper material comprising:

a fabric attached to the sole, wherein tension within the upper material alters as the sole changes in shape during the gait cycle; and

a reinforcing element around an Achilles tendon or ankle joint of the foot to enhance support.

25. The shoe of statement 24, wherein altered tension generates a pressure difference across the foot.

26. The shoe of statement 24 or 25, wherein:

the fabric is a stretch knit fabric, and

the reinforcing element is a thicker fabric than the stretch knit fabric or an adjusted knitting pattern to the stretch knit fabric.

27. The show of any of statements 24-26, wherein a force pressure shift resulting from the upper material stimulates mechanoreceptors of the foot.

28. The shoe of any of statements 24-27, further comprising a strap at the back of the shoe for slip-on functionality.

29. The shoe of statement 28, wherein the strap comprises a hook-opening mechanism.

30. The show of any of statements 24-29, wherein the upper material further comprises one or more elastic strips located alongside the midfoot and rearfoot areas.

31. The show of any of statements 24-30, wherein the upper material further comprises a flexible bow element positioned in the midfoot area.

32. The shoe of any of statements 24-31, wherein the shoe weighs less than 500 grams.

33. The shoe of any of statements 24-31, wherein the shoe weighs less than 300 grams.

[0066] Any of the above statements can be combined and the skilled person would understand such examples do not limit the potential embodiments of the present disclosure.

[0067] The skilled person will also understand that any use of “or” throughout the statements of invention or description herein encompasses use of “or”, “and/or”, and “and”. For example, the term "or" within the discourse is construed to encompass both "and" and "and/or" owing to its inherent inclusivity. Within linguistic reasoning, "or" denotes an inclusive disjunction, allowing for the consideration of scenarios wherein either one condition holds true, the other condition holds true, or both conditions hold true concurrently. This interpretation inherently incorporates the conjunction "and", permitting the acknowledgment of scenarios wherein multiple conditions coexist. Additionally, the term "and/or" explicitly acknowledges the possibility of either condition being singularly true or both conditions being true simultaneously, thus aligning with the broader meaning of "or" within the context of this disclosure. Consequently, "or" functions as a flexible connector within the statements of invention, accommodating both exclusive and inclusive interpretations to suit the nuanced requirements of embodiments described herein.

Claims

1. A sole for improving gait stability or balance, the sole comprising:

a separation from a neighbouring protrusion of between 10 and 20 mm, measured from an apex of the protrusion and an apex of the neighbouring protrusion; and

2. The sole of any preceding claim, wherein the plurality of protrusions comprises one or more spherical caps.

3. The sole of any preceding claim, wherein alignment of the plurality of protrusions is based on proprioception of the foot and facilitates a distribution of force during a stational position or during a gait cycle.

4. The sole of claim 3, wherein the distribution of force is configured to result in perturbations for an equilibrium, activating muscles of the foot.

5. The sole of any preceding claim, wherein a position of each protrusion is calculated based on biomechanical principles active during the gait cycle.

6. The sole of any preceding claim, wherein:

the anatomy of the foot comprises a forefoot, a rearfoot, and a midfoot,

the sole comprises a wide-cut forefoot area, a rearfoot area, and a midfoot area corresponding to the anatomy of the foot, and

the width of each protrusion of the plurality of protrusions is determined by which area of the sole the protrusion is placed.

7. The sole of claim 6, wherein:

the rearfoot area comprises one or more protrusions having a first width;

the midfoot area comprises one or more protrusions having a second width, wherein the second width is smaller than the first width; and

the wide-cut forefoot area comprises one or more protrusions having a third width, wherein the third width is smaller than the second width.

8. The sole of claim 1, wherein the sole comprises a flexible material up to 2 cm thick.

9. The sole of claim 8, wherein the flexible material is any of: a polyvinyl chloride compound, a soft polyvinyl compound with a shore value of between 30 and 60, Ethylene Vinyl Acetate, natural rubber, or Algae Biomass.

10. The sole of any preceding claim, wherein the sole is configured without an arch support or a footbed.

11. A stimulated functional foot active system for dynamic support based on foot position while standing and walking, the stimulated functional foot active system comprising the sole of any preceding claim, wherein the sole is configured to facilitate higher recruitment of the muscles when weight load is applied to the functional foot active system.

12. A shoe comprising an upper material and the sole of any of claims 1-10, the upper material comprising:

a reinforcing element around an Achilles tendon or ankle joint of the foot to enhance proprioception support.

13. The shoe of claim 12, wherein a force pressure shift resulting from the upper material stimulates mechanoreceptors of the foot.

14. The shoe of claim 12 or 13, further comprising a strap at the back of the shoe for slip-on functionality.

15. The shoe of any of claims 12-14, wherein the shoe weighs less than 500 grams.