Patent Application
20190021438
The present disclosure relates to an orthotic device for shoes. In particular, the present invention relates to an orthotic device for dress shoes. However, it will be appreciated by those skilled in the art that the present invention may be used in other applications and in particular with other shoe types.
Foot orthotic devices (also known as orthoses) are commonly prescribed by health professionals to alter foot kinetics, improve function, provide cushioning, reduce pain, prevent injury and redistribute forces acting upon the lower limb musculoskeletal system.
Foot orthotic devices may be made to an individual's customized prescription or manufactured for the mass population and are usually designed specifically for a certain type of footwear including running shoes, work shoes and high heels.
A customised orthotic prescription is made from an impression of the individual's foot and manufactured to a personalised prescription fitting the morphology of the individual's foot. In contrast, an off-the-shelf orthotic (also known as a generic orthotic/orthoses) is manufactured commercially and generally has a prescription that would suit the average of the intended population.
Generic orthoses applicable for use in a heeled shoe currently commercially available are either:
High heels are worn, generally by women, to achieve an appealing posture, height gain and to accompany an outfit. When wearing high heels, modification of walking gait is required to accommodate the pitched heel, such that the higher the heel pitch, more accentuated biomechanical changes occur.
For the purpose of this application, heeled shoes are defined as any shoe with a heel to toe vertical difference (heel pitch) greater than 30 mm, with the heel raised higher than the forefoot.
The adaptations with standing and walking in a heeled shoe are widely documented, identifying significant differences compared to the mechanics and posture that occurs in a flat-soled shoe. When walking in a high heel, it has been previously identified that the natural position of the foot and ankle is altered with the ankle forced to maintain a plantar flexed position (ankle extends in a downward direction with the forefoot positioned towards the ground) and the big toe joint constantly forced into a dorsi flexed position. It is also well known that the wearer has to actively accommodate for the heel height in contact, stance and swing phases of gait through musculoskeletal compensations at the foot, ankle, knees, hips and spine including a change of the wearer's center of mass, forward trunk lean, forward positioning of the chest, shorter stride length, the buttock protrudes, significant increase in pressure loading though the forefoot, increased rigidity through the arch of the foot, reduced shock absorption, shortened calf muscle length and altered muscle activation of the lower limb and spine.
The long-term effect of wearing a high heel habitually has been widely documented. Links have been drawn between prolonged high heel use and chronic ailments including osteoarthritis and musculoskeletal pain involving the foot, ankle, knees, hips and spine. Boney deformities including bunions (HAV), hammertoe, collapsed metatarsal arch as well as anatomical changes including a shortened calf muscle and thickened Achilles tendon are all linked to long term use of high heels.
It is also widely documented that the increase in heel height directly relates to a significant increase in peak pressure of the forefoot. The greater the heel to toe vertical difference, the higher the percentage of body weight carried by the forefoot.
In 1954 Hicks identified that when passive dorsiflexion is applied to the hallux (i.e. when the heel raises during walking gait) it sequentially initiates the plantar aponeurosis to tighten, followed by the rise of the medial longitudinal arch, the rearfoot inverts and the tibia/fibula complex externally rotates. This is known as the “windlass mechanism”.
Although the windlass mechanism is commonly appreciated by those skilled in the field, the link between heeled shoes causing the over-activation of the windlass mechanism leading to ankle instability and subsequent pain is unidentified by those in the field and the literature.
Existing off-the-shelf orthoses manufactured for wear within heeled shoes and other types of dress shoes are designed with variations of medial arch support and cushioning. The widely accepted design and concept is based on supporting the medial arch plus additional forefoot cushioning.
Orthoses that concentrate support on the medial arch and/or medial foot including a varus wedge will amplify over-supination, contributing further instability and associated pathologies when used in heeled shoes.
In addition to the inventions use in a heeled shoe to overcome the above mentioned biomechanical changes, the design can be utilized by persons requiring support of their lateral foot in flat shoes and/or sport shoes, particularly a person who has a high arched foot, a person who suffers with chronic ankle instability or a person suffering with acute strain or overuse of the lateral leg musculature.
The invention may also be appropriate for persons with medial knee arthritic degeneration or persons who excessively wear the lateral outsole of their shoes.
For the purpose of this application, the following definitions are applied:
Supination, is a triplanar motion of the foot and ankle complex that creates inversion of the subtalar joint, elevation of the medial arch, a locking mechanism of the pedal joints, adduction of the forefoot and plantar flexion of the ankle causing a laterally deviated subtalar joint axis. Generally speaking, a supinated foot posture is identified as a predominantly high arched foot with an inverted alignment of the heel in resting calcaneal stance position. For the purpose of this application, over-supination is when supination occurs out-of-phase during gait or is in excessive proportion.
Pronation is a triplanar motion of the foot and ankle complex that creates eversion of the subtalar joint, lowering of the medial arch, unlocking of the pedal joints, abduction of the forefoot and dorsi flexion of the ankle causing a medially deviated subtalar joint axis. Generally speaking, a pronated foot posture is identified as a predominantly low arched foot with an everted alignment of the heel in resting calcaneal stance position. For the purpose of this application, over-pronation is when pronation occurs out-of-phase during gait or is in excessive proportion.
Inversion of the subtalar joint is a frontal plane movement of the heel (calcaneus) that is identified by the distal portion of the heel directed towards the midline of the body (inwards). For the purpose of this application, inverted is interchanged with varus.
Eversion of the subtalar joint is a frontal plane movement of the heel (calcaneus) that is identified by the distal portion of the heel directed away from the midline of the body (outwards). For the purpose of this application, everted is interchanged with valgus.
Moment is a turning effect caused by a force applied about a radius. Moment=F×r
A medial post is a firm external notch or flare located on the medial side of the device that is balanced to neutral to reduce any medial ‘rocking’ movement of the orthotic device. It may, or may not, be made from the same material as the shell of the orthotic.
A lateral post is a firm external notch or flare located on the lateral side of the device balanced to neutral to reduce any lateral ‘rocking’ movement of the orthotic device. It may, or may not, be made from the same material as the shell of the orthotic.
A varus wedge may be located internally (i.e. medial skive) or externally (varus posting) to the orthotic shell at the rearfoot, midfoot and/or forefoot. A varus wedge is higher on the medial side than the lateral side and this can be measured in either degrees or millimeters. It will invert the corresponding location on the foot by shifting the centre of pressure medially.
A valgus wedge is located internally (i.e. lateral skive) or externally (valgus posting) in the orthotic shell at the rearfoot, midfoot and/or forefoot. A valgus wedge is higher on the lateral side than the medial side and this can be measured in either degrees or millimeters. It will evert the corresponding location on the foot by shifting the centre of pressure laterally.
The neutral position of the foot (known as Neutral Calcaneal Stance Position NCSP) is where the talonavicular joint should be congruous and the mid position of the subtalar joint complex is not inverted, nor everted.
The resting position of the foot (known as Resting Calcaneal Stance Position RCSP) is where a person is positioned whilst in relaxed standing. This measurement is taken in relation to vertical or NCSP. Most people stand naturally with their RCSP either everted or inverted.
The medial longitudinal arch of the foot relates to the longitudinal space between the calcaneus, talus, navicular, three cuneiforms and 1st/2nd/3rd metatarsals. The summit is at the superior articular surface of the talus, and two piers on which it's supported whilst in standing are the tuberosity on the plantar surface of the calcaneus posteriorly and the heads of the first, second, and third metatarsal bones anteriorly. Generally, in a heeled shoe, the passive dorsiflexion of the hallux causes the medial longitudinal arch of the foot to rise. The medial arch height of the orthotic device is measured as the distance between the lowest position of the dorsal shell
The lateral longitudinal arch is the arch on the lateral side of the foot, concave inferiorly, formed by the metatarsal bones, the three cuneiform bones, the cuboid and the calcaneus. A cuboid notch is a common form of lateral arch support within an orthotic device. The lateral arch height of the device is measured as the distance between the lowest position of the dorsal shell
The subtalar joint is also known as the talocalcaneal joint and it is the key joint of the rearfoot. It creates inversion and eversion and when moved in conjunction with the midfoot creates supination and pronation.
The heel cup is the height measured from the lowest position of the dorsal shell
The shell is the material that embodies the device in its entirety from the posterior heel cup to the anterior edge. The shell may cease anteriorly either under the metatarsals, toes or extend past the toes to the full length of the shoe.
The top cover is the material to overly the shell of the device, it may end at the anterior edge of the shell or may continue anteriorly. It may be made from the same material as the shell or from a differing material to the shell.
Shank of the shoe is the rigid structure of the sole located between the insole and outsole that supports the arch of the foot.
It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above described biomechanical complications associated with a heeled shoe.
It is an objective to provide an orthotic device that concurrently provides anatomically and biomechanically applicable cushioning, foot support and ankle stability by means of lateral foot support, medial arch support and shock-absorbing materials.
It is another objective to provide an insole or shoe shank structure that can be fixed internally during the manufacturing process or added to the shoe by the user after purchase.
In a first aspect, the present invention provides an orthotic device for use with a flat, sport, dress or heeled shoe, the device comprising:
a body portion;
a medial arch defined by a projection extending upwardly away from the body portion; and
a valgus wedge located at a rearfoot portion, midfoot portion and forefoot portion of the body portion, the valgus wedge being adapted to concentrate support under the lateral foot.
The valgus wedge preferably extends along the lateral border of the orthotic device from the rearfoot portion to the forefoot portion.
The valgus wedge is preferably angled at about 7 degrees (approx. 4.5 mm in vertical height) relative to the body portion however this measurement may be increased or decreased depending on the purpose of the device and may measure between 2 mm and 20 mm where the lateral border is vertically higher compared with the medial border of the device.
The valgus wedge is preferably an internally fixed lateral skive.
The orthotic device further may comprise of a lateral arch defined by a projection extending away from the body portion vertically, the lateral arch being highest at a lateral portion of the device, and adapted to be located generally under a cuboid bone of a user's foot.
The orthotic device further may comprise of a metatarsal bar.
In a second aspect, the present invention provides a method of fitting an orthotic device to a shoe, the method including the step of:
sizing the orthotic device such that a length of a body portion of the orthotic device generally corresponds with a length of a user's foot or the proximal portion of the users foot;
wherein the orthotic device including a valgus wedge located at a rear foot portion and/or a forefoot portion of the body portion, the valgus wedge being adapted to concentrate the support under the lateral foot.
The method further may include the step of locating a lateral arch which extends upwardly away from the body portion such that a high point of the lateral arch is generally positioned beneath a cuboid bone of a user's foot.
The method further may include the step of adding a self-adhesive layer to the plantar surface of the body at either, or both, the rearfoot and/or forefoot that prevents the orthotic device from moving or sliding within the shoe. This may, or may not, be removable and reusable. This embodiment does not alter the overall wedging of the orthotic device.
In the third aspect, the present invention provides a design platform for modification to the design of the shank or insole of a high heel and may be integrated directly to the shoe during the manufacturing process. The present invention's design may include, but is not limited to, the valgus wedge extending from rearfoot to forefoot along the sole of the heeled shoe. In this instance, the body portion of the present invention is incorporated into the design of the shank or insole of the shoe.
The inventor has conducted a clinical study and preliminary research that links the passive dorsiflexion of the hallux in a heeled shoe with the constant activation of the windlass mechanism causing subtalar joint inversion, foot supination and subsequent lateral instability. The findings of this research directly correlated the supinated foot position with musculoskeletal fatigue and pain associated with wearing high heels.
Subsequently, the inventor has applied the innovative findings from the preliminary research to design a unique high heel insole structure that applies an eversion force at the rearfoot, midfoot and forefoot as well as medial arch contour. The eversion force of the insole acts against the supinatory force of the foot, thus minimising the biomechanical complications associated with a heeled shoe (outlined below). The invention also incorporates shock-absorbing material that is of malleable formation throughout the insole structure.
To further highlight the findings of the research behind the invention:
In summary, it is findings of the inventor's research that the consistent activation of the windlass mechanism, causing supination of the foot and creating imbalance between the medial and lateral ankle/lower limb musculature, plus out-of-phase recruitment of the secondary ankle stabilizers that is responsible for the onset of heeled shoe related foot and limb pain as well as toe clawing and deformity related to heeled shoe use.
The design of the preferred embodiment incorporates a rearfoot, midfoot and forefoot valgus design that assists the foot to withstand the supinatory forces caused by the constant activation of the windlass mechanism and therefore provides lateral foot and ankle stability. This in turn reduces the eccentric load on the lateral ankle stabilisers (both primary and secondary) thus minimising subsequent muscular fatigue, musculoskeletal pain, joint load and biomechanical compensation.
A preferred embodiment of the invention will now be described by way of specific example with reference to the accompanying drawings, in which:
A valgus wedged orthoses or orthotic device 10 is disclosed herein for use primarily with heeled shoes of more than 3 cm. However the orthotic device 10 can be used in other shoe types including sports, flat, sandal and dress shoes. The orthotic device 10 concentrates the support under the lateral rearfoot, lateral midfoot and lateral forefoot, minimizing the degree of supination of the foot. The biomechanical changes that occur by minimizing the degree of supination of the foot in a heeled shoe include stabilisation of the lateral ankle, unloading of the peroneal and lateral gastrocnemius musculature and reduced out-of-phase activation of the flexor and extensor musculature.
Existing orthotics for heeled shoes feature support concentrated in the medial arch and some comprise of a varus wedge of the rearfoot and/or forefoot, potentially exacerbating the negative biomechanical changes associated with a heeled shoe. The orthotic device 10 disclosed herein provides the opposite force to the foot, concentrating the support on the lateral foot to align the foot closely to neutral, preventing over supination and the associated biomechanical changes whilst in a heeled shoe.
Whilst the orthotic device 10 concentrates the majority of support along the lateral border of the foot, the orthotic device 10 also includes a medial arch support 40 for the population of users that require medial longitudinal arch support whilst wearing a heeled shoe. The vertical height of the medial arch contour or support 40 is not sufficiently large to apply a varus force to the foot and therefore will not exacerbate the negative biomechanical changes associated with a heeled shoe.
Referring to
The orthotic device 10 includes a body portion or shell 25, providing a soft and flexible platform for supporting and cushioning the foot. The medial arch contour 40 is soft and malleable to provide comfort and prevent over pronation of the foot in those consumers that require medial support.
The orthotic device 10 includes a valgus wedge 20 which supports the lateral foot to reduce the supinatory effect of the windlass mechanism whilst in a heeled shoe. The valgus wedge 20 may be a lateral skive or alternatively an external valgus posting.
The orthotic device 10 may be used with shoes types including but not limited to heeled shoes (of varying vertical pitches), dress shoes, flat shoes, sandals, wedges and sports shoes. The orthotic device 10 may be provided as an off-the-shelf orthotic device 10 which can be added to any appropriate footwear by the consumer. Alternatively, the orthotic device 10 may be added during the shoe manufacturing process in replacement of the standard shoe liner (insole) and sold as an inclusion to the shoe.
The shape and contours of the orthotic device 10, the valgus wedge 20 extending from the rearfoot distally through to the forefoot as well as the medial arch contour 40, may be applied to form the shank of the heeled shoe during the manufacturing process.
Referring to
The high, lateral side of the device 10 includes the valgus wedge 20 in addition to the 1.5 mm body or shell 25 thickness that tapers from the lateral side to the medial side of the device 25. That is, a high point is defined by the orthotic tapering upwardly away from the body 25 portion at an angle of approximately 7 degrees (approximately 4.5 mm total vertical height) however could be up to 20 mm toward the lateral side. The wedge 20 effect can best be seen in
The orthotic device 10 includes medial arch support 40, as identified in
The medial arch support 40 ascends gradually in height from posterior to anterior, with the highest point located at the approximate mid point of the arch before descending toward the anterior in a similar gradient. The height of the medial arch support 40 also descends laterally away from the medial side. Referring to
The medial arch support 40 assists wearers who pronate.
As depicted in the embodiments of
In some embodiments, the orthotic device 10 may include a top cover or layer. The top cover material will be evenly adhered across the entire dorsal surface of the orthotic device 10, thus not altering the overall wedge of the device and therefore this measurement is not included in the diagrams.
In some embodiments, the orthotic device 10 may include an increase in height at the metatarsal arch region, to define a metatarsal support 60, beneath a metatarsal arch region of the foot.
In some embodiments, the orthotic device 10 may include a lateral arch support 50 (also referred to as a cuboid notch) that provides further lateral foot support in addition to the valgus wedge 20. As indicated in
The orthotic device 10 addresses the over-supination of a user's foot whilst the ankle is positioned in a high degree of plantar flexion when wearing heeled shoes. Accordingly, the orthotic device 10 addresses the subsequent biomechanical changes that occur to the foot in the transverse and frontal planes (as identified above) whilst in a heeled shoe. This design and concept may be used in further research, prescription of orthoses as well as the design and manufacture of footwear and off-the-shelf orthotic devices.
The orthotic device 10 concentrates the support under the lateral rearfoot, lateral midfoot and lateral forefoot with a valgus wedge 20 to balance the foot and ankle whilst in a heeled shoe. The orthotic device 10 may be manufactured and sold as an orthotic device that is off-the-shelf, customized with additions or applicable during the footwear manufacturing process to be glued, adhered or sewn into the shoe during manufacturing.
The following elevations and materials directly relate to the drawings, and description of the drawings, associated with this application.
For the purpose of this application, the measurements are standardised to the size of a small orthotic device 10 and the measurements will either increase with larger sizes or decrease with smaller sizes. When this concept is applied during the footwear manufacturing process the dimensions may be altered for a custom fit to the last. In this case it may replace the standard shoe liner and therefore the dimensions will extend to the perimeters of the shoe as per a standard shoe liner.
The orthotic device 10 for heeled, dress or flat shoe will be appropriately dimensioned for a narrow and shallow shoe. The shell or body portion 25 may be manufactured from, but not limited to, open or closed cell polyethylene foam, open or closed cell polyurethane foam, cross linked polyethylene foam, EVA foam (Ethylene Vinyl Acetate), gel, silicon, polypropylene, or any other cellular rubber and/or foam material. The shell 25, valgus wedge 20 and medial arch support 40 may be a combination of thickness, density and/or materials.
The top cover may be made from, but not limited to, open or closed cell polyurethane, open or closed cell polyethylene, foam materials, cellular rubbers, neoprene, nylon, vinyl, leather, gel and silicon. The top cover may, or may not, extend the full length of the device 10.
The high point of the medial arch support 40 (
The lateral arch support 50 is an additional feature according to a preferred embodiment (
The valgus wedge 20 may extend from the rearfoot through to the forefoot, or may partially extend, or taper to reduce the valgus support, between the rearfoot and forefoot. At the forefoot, the valgus posting will be 0 mm under the medial side of the 1st metatarsal head and extends transversely under the lateral side of the 5th metatarsal shaft to measure up to 20 mm. The heel cup height will be dictated by the valgus wedge 20 height on the lateral side (up to 20 mm) and will be the minimal thickness of the shell on the medial side (
In one embodiment, as depicted in
Advantageously, the valgus wedge 20 significantly reduces the degree of foot supination caused by the plantar flexed position of the ankle whilst in a heeled shoe.
Advantageously, by reducing the degree of supination of the foot, the orthotic device 10 improves the balance between the medial and lateral ankle stabilising musculature and reduces the activation of the secondary ankle stabilizers thus reducing the clawing effect of the toes.
Advantageously, by improving ankle stability, those who use this orthotic device 10 may experience less muscle fatigue, less pain, greater endurance, reduced lateral ankle instability and reduced likelihood of associated injuries such as falls, fractures, ligamentous strain, tendinopathies and soft tissue overuse associated with walking and standing in heeled shoes.
Advantageously, the orthotic device 10 reduces the degree of supination at the forefoot, midfoot and rearfoot by applying an angular force concentrated under the lateral forefoot, lateral midfoot and lateral rearfoot.
Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015903126 | Aug 2015 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2016/050709 | 8/5/2016 | WO | 00 |
