AU2005319806B2 - Orthotic kits and assemblies - Google Patents

Description

WO 2006/068513 PCT/NZ2005/000334 ORTHOTIC KITS AND ASSEMBLIES The present invention relates to orthotic kits and assemblies, insoles for footwear, orthotic inserts for footwear and related products, sub-assemblies, assemblies, procedures and methods. The subject invention differs from previous similar devices through being based on new scientific models, of FORCE and BALANCE, related to the function of the foot and leg.

Orthotic inserts have been developed since the 1960's for achieving desirable outcomes in a variety of lower limb conditions like plantar fasciitis, Achilles' Tendinitis, shin splints, runner's knee and other painful conditions affecting the musculoskeletal system including hip and back conditions.

Such devices, pioneered by Dr Merton Root unlike pre-existing "arch supports", were based upon a biomechanical model of foot and leg function that enabled the prescription and fabrication of foot orthoses (or orthotics) intended to alter the interrelated alignment and motion of anatomical segments of the foot and leg. Such orthotic inserts for footwear had a major impact inter alia in the treatment of sports injuries.

The biomechanical or "Podiatric" model on which the prescription and fabrication of Foot Orthoses has been based has, more recently, been challenged as a result of scientific investigations, which do not substantiate it's claims to be a valid model for understanding and improving foot and leg function.

More comprehensive models have been proposed, which place more emphasis on proprioception, balance and the amount of muscle exertion required to alter the position of lower limb segments, to replace, augment or expand the prevailing biomechanical model.

Recent scientific studies of the Efficacy of Foot Orthoses have shown that they are a reliably effective therapeutic modality. However, these studies have also raised doubts as to the validity of the biomechanical model on which they are based.

The subject invention discloses a new type of foot orthoses system comprising a shoe insole with related inserts and wedges specifically designed to alter the function of the lower limb.

While the basic principles of moulded insoles, depressions, inserts and wedges may be relatively common, the present form and intention of such components is original and unique in the prior art.

Wedges, in the prior art, have been of various measured degrees and intended to correct malalignments of particular structural components of the foot.

The wedges, in this instance, are intended to be progressively introduced from the periphery of the device to exert a force under a particular area of the sole of the foot. In WO 2006/068513 PCT/NZ2005/000334 -2relation to this invention, a wedge is used to exert a force as a wedge might be driven progressively into a log of wood to split it. Preferably the wedge is of an angle of approximately but the exact angle is not critical.

This gradual introduction of the wedge progressively increases the force on the under surface of the foot until a desired change is observed in balance or the force required to supinate the foot or activate the windlass mechanism.

The use of wedges in this invention is thus related more to the depth of insertion of the wedge that to the angle of the wedges revealed in the prior art.

In 1981 New Zealand Patent 196010 (Baycroft) in discussing prior art so called "customised" insoles disclosed an insole blank having advantageous features and capable of being made and conformed to a wearer's customised use by a procedure involving temperature after the creation of the retail item. The insole as retailed was sculpted from a sheet of a suitable material which is thermoplastic with a softening point temperature above ambient temperature but at which the materials safely may be brought into contact with or into proximity to human skin and to which footwear materials may be heated without damage.

One suitable material disclosed was medium density closed cell foamed polyethylene having a shore hardness The Baycroft developments in orthotic insoles has been commercialised as the

FORMTHOTIC

T M range of products by ourselves.

In US Design Patents US D 498577 and US D 497470 there is disclosed insoles having relief features for location of wedges as inserts at each of the medial sides of the forefoot and the rearfoot. As commercialised as the PROSTEPTM orthotic range, the product was of EVA with the insole of shore hardness 45 and the wedges of shore hardness We believe that orthoses or orthotics can be further improved by taking into account the following: The force required under the foot to supinate the subtalar joint varies significantly (from 35 to 3 85 Newtons) from person to person and is greater in people who are prone to foot and leg problems. We have determined that a wedge to the medial rearfoot can reduce the force required to resupinate the foot.

The force required to activate the windlass effect varies significantly from person to person and is greater in people who are prone to foot andleg problems, especially plantar fasciitis. We have determined that providing a depression under the big toe and/or adding a wedge to the lateral side of the forefoot under the ball of the foot and behind the WO 2006/068513 PCT/NZ20051000334 metatarso-phalangeal joint of the smallest toe) can reduce the force required to activate the windlass mechanism and supinatc the foot.

Proprioception, Balance and Stability are important aspects of Foot and leg function that have been ignored in previous models. We have determined that balance (as examined by having the subject stand on one leg with the eyes closed) can be significantly altered by standing on the orthotic and further altered by progressively introducing a wedge under the lateral aspect of the rearfoot. The introduction of this wedge must be done with care, however, because excessive insertion or angulation of the wedge can cause the subject to become unstable and prone to falling laterally off the foot.

We have also observed that the ability to rise smoothly onto the toes and maintain reasonable balance in this position is impaired in most people with foot and leg problems and can be improved significantly by using properly fitted and wedged orthotics. Having stable forefoot support improves the efficiency of propulsion. This stability is usually improved by allowing a depression beneath the big toe alone or in conjunction with the progressive introduction of a wedge under the lateral forefoot. It is essential to use only the amount of wedge required to improve stability as too much or too great an angle can create instability.

In addressing the prospect of orthotic customisation but using a kit of components to be assembled we are not intending a deliberate altering of the alignment or motion of parts of the foot but are intending to alter the forces acting on the under surface of the foot. The TALAR MADETM pads or wedges utilised with insoles of the kind referred to in the aforementioned US Design Patents relates to the older theory of controlling motion. The present invention is directed to altering balance and/or the forces acting on various areas under the foot to improve specific aspects of foot and leg function.

We have additionally determined the utilisation of at least two inserts as hereinafter discussed and/or wedges to provide a synergistic effect and enhance the wearer's balance, stability and comfort and to reduce the moment of rotational force acting on the calcaneaus at heel strike to accelerate the pronation of the foot and reduce the force required to be exerted by the muscles of the foot and leg to supinate the foot and to reduce the force acting on the plantar fascia to enable the activation of the windlass mechanism of the foot.

We favour a shock absorbing piece on the lateral side of the heel. This position relates to the fact that heel contact is usually made with the lateral edge of the heel and hence tends to wear away this area of shoes. Such a shock absorbing insert there helps to reduce the moment of force acting on the Calcaneus to accelerate the pronation of the foot and also to help reduce wearing away of the outer edge of the heel of the shoe. This feature can also be WO 2006/068513 PCT1NZ20051000334 claimed to reduce both the amount and the velocity of rearfoot pronation and, in association with any wedge supplied for the medial rcarfoot, to synergistically help to reduce the force and rate ofpronation.

A shock absorbing insert under the big toe is there to help reduce the force acting on this region when pushing off and also to allow the base of the big toe ball of the foot) to sink into the device, in a controlled fashion, so that the windlass mechanism can act effectively. This is necessary to reduce the strain in the plantar fascia and also to reduce the force that the muscles of the foot and leg must exert to accomplish supination of the foot. The shock absorbing material may also be removed from the depression under the big toe to increase the ability of the toe to drop down in instances where this is required. It is particularly relevant to people who have inflammation of the plantar fascia, causing pain in the heel.

A lateral wedge for the front of the device synergistically adds to the effect of activating the windlass in cases where more force is needed. In addition to this beneficial effect on the establishment of the windlass mechanism, the lateral wedge is introduced progressively until the force exerted on the forefoot is sufficient to improve the stability of balance when standing on the front of the foot with the heel elevated from the ground, thus providing a stable platform for propulsion in walking or running.

So, these rearfoot and forefoot features actually work together "synergistically" and enhance the effect of the heel shock absorber and/or the depression under the big toe by adding the force effect of the wedges or either wedge.

In a first aspect the invention consists in an orthotic kit comprising or including a contoured insole.

a wedge for location under the lateral region of the fore foot region of the insole, and a wedge for location under the medial region of the rear foot region of the insole.

Preferably there is also an insert or pad for a medial region of the fore foot or optionally the insole having such an insert or pad fitted thereto.

Preferably there is also an insert or pad for a lateral region of the rear foot, or, optionally the insole having such an insert or pad fitted thereto.

Preferably both an insert or pad for a said medial region of the fore foot and an insert or pad for the lateral region of the rear foot region of the insole.

Preferably the insert or pad of each of the medial region of the fore foot and the lateral region of the rear foot region is pre-fitted.

WO 2006/068513 PCT/NZ20051000334 Preferably at least one wedge is of fixed wedge angle and the intrusion extent of its location will determine the corrective force being applied.

Preferably the wedge angle is about 6°.

Preferably both wedges are of wedge angle about 6°.

Preferably at least one wedge has a wedge angle from 3° to 90 or ranging from 30 to 9°.

Preferably at least one or each wedge is at least as hard as the contoured insole.

Preferably the insert or pad of the medial region of the forefoot and the insert of pad of the lateral region of the rearfoot is softer or more energy absorbent than the material(s) of the insole.

Preferably the insole is for part only of the foot.

Preferably the insole is for at least substantially all of the foot.

Preferably raised lines on the sole of the insole define a zone for each wedge.

Preferably a depression in the sole of the insole defines one zone for a said wedge.

Preferably adapted to applying or altering forces that act on the foot.

Preferably adapted to be used to improve proprioception, stability and balance when standing with the entire foot in contact with the surface beneath.

Preferably adapted to reduce the moment of force acting on the posterolateral border of the heel at heel strike/contact and that accelerates the angular momentum of pronation of the subtalar joint without reducing the physiological range of motion of pronation of the subtalar joint.

Preferably the features and components of the forefoot area are there to improve stability and balance when rising onto and standing on the toes during the propulsive period of gait.

Preferably wedges are used, or are to be used, as a means of applying force to particular sites on the sole of the foot and the amount of force is to be dependent on the depth of intrusion of the wedge under the insole.

Preferably to be used as part of an interactive clinical and practical method for altering the function of the foot and leg.

We have found that the resistance to supination has to be overcome by the force of contraction of muscles in the lower limb and that by using a wedge to apply a force under the medial side of the heel, we are reducing the strain in these muscles and the work that they have to do.

WO 2006/068513 PCT/NZ20051000334 We also find that the force required to activate the windlass mechanism is an indication of the resistance to rising efficiently onto the toes for propulsion and that reducing this results in a decrease in the strain exerted on the plantar fascia and other related tissues and structures in the lower limb, including the Achilles' Tendon.

The apparatus also consists in combination as a kit, at least one kit as aforesaid for one foot and at least a contoured insole for the other foot.

The invention also consists in two such kits, one for each foot.

Preferably the apparatus is packaged with instructions as to its assemblage and use.

Preferably the packaging includes some expression of advantages to be derived from the use.

In another aspect the invention consists in an orthotic kit, or assembly thereof, comprising or including a contoured insole, the insole defining zones (optionally a depression or depressions) and/or pockets for the location of a pad or pads and/or an insert or inserts, and at least one of [preferably both]: (II) a depressible insert or pad under the ball of the foot and/or the big toe region(s) of the insole, and/or (ii) a depressible insert or pad under the lateral region of the heel region(s) of the insole.

In another aspect the invention consists in an orthotic kit, or assembly thereof, comprising or including a sculpted or moulded insole, the insole defining zones and/or pockets for the location of a pad or pads and/or an insert or inserts, and (II) one or more of (ii) and (iii), viz a depressible insert or pad under the ball of the foot and/or the big toe region(s) of the insole, (ii) a depressible insert or pad under the lateral region of the heel region(s) of the insole, and (iii) raised lines or outlines under the medial region of the heel and lateral region of the forefoot to indicate the position in which wedges may be placed to modify the insole.

Preferably the insole is "moulded" by compression forming (with heat) a foam thermoplastic sheet or preform.

WO 2006/068513 PCT/NZ20051000334 Preferably the zones or pockets are on the underside of the insole (preferably zones and not pockets).

Preferably the zones are depressions or rebates ("depressions").

In another aspect the invention consists in an orthotic kit, or assembly thereof, comprising or including a moulded compression formed) insole, and two inserts therefor, such inserts being adapted for location to underside zones of the moulded insole so as to provide a depressible region under the ball of the foot and/or the big toe, and/or a depressible region under the lateral region of the heel, [the inserts or pads preferably being characterised in that they have a hardness less than (or substantially not more than) that of the moulded insole].

In a further aspect the present invention consists in an orthotic kit, or assembly thereof, comprising or including a contoured insole, and (II) at least one or more of: an insert or pad for location under the medial region of the forefoot, the ball of the foot region, and/or at least part of the big toe region of the insole, (ii) an insert or pad for location under the lateral region of the heel or rearfoot region of the insole, (iii) a wedge insert or pad for location under the medial region of the rearfoot region of the insole, and/or (iv) a wedge insert or pad for location under the lateral region of the forefoot region of the insole.

In a further aspect the present invention consists in an orthotic kit, or assembly thereof, comprising or including a sculpted or moulded compression formed) insole, and (II) at least one or more of: an insert or pad for location under the medial region of the forefoot, the ball of the foot region, and/or at least part of the big toe region of the insole, (ii) an insert or pad for location under the lateral region of the heel or rearfoot region of the insole, (iii) a wedge insert or pad for location under the medial region of the rearfoot region of the insole, and/or WO 2006/068513 PCT/NZ2005/000334 -8- (iv) a wedge insert or pad for location under the lateral region of the forefoot region of the insole.

In a further aspect the present invention consists in an orthotic kit, or assembly thereof, comprising or including a (preferably contoured) insole, and an insert or pad for location under the medial region of the forefoot, the ball of the foot region, and/or at least part of the big toe region of the insole, an insert or pad for location under the lateral region of the heel or rearfoot region of the insole, and one or both: a wedge insert or pad for location under the medial region of the rearfoot region of the insole, and/or a wedge insert or pad for location under the lateral region of the forefoot region of the insole.

In a further aspect the present invention consists in an orthotic kit, or assembly thereof, comprising or including a moulded insole, and at least one or more of: an insert or pad for location under the medial region of the forefoot, the ball of the foot region, and/or at least part of the big toe region of the insole, (ii) an insert or pad for location under the lateral region of the heel or rearfoot region of the insole, (iii) a wedge insert or pad for location under the medial region of the rearfoot region of the insole, and/or (iv) a wedge insert or pad for location under the lateral region of the forefoot region of the insole, wherein either or both an insert or pad and/or (ii) is present and has (have) a hardness less than (or substantially not more than) that of the moulded insole, and/or an insert or pad and/or (ii) is present and a wedge or pad (iii) and/or (iv) is also present and the hardness of component(s) and/or (ii) is (are) less (or substantially is not more than) that of component(s) (iii) and/or and/or WO 2006/068513 PCT/NZ20051000334 -9an insert or pad and/or (ii) is present and a wedge or pad (iii) and/or (iv) is also present and the component(s) and/or (ii) is more depressible and/or energy absorbing than the component(s) (iii) and/or (iv).

In another aspect the invention is a method of fitting an orthotic, said method involving a kit in accordance with the present invention, and prior to and/or during fitting into an item of footwear, locating and/or adhering a said insert or pad under each of the media region of the forefoot, the ball of the foot region and/or at least part of the big toe region of the insole, and the lateral region of the heal or rearfoot region of the insole, and, optionally, one or both a wedge insert or pad under the medial region of the rearfoot region of the insole and a wedge insert or pad under the lateral region of the forefoot region of the insole.

Moreover the present invention also consists in an insert, pad and/or insole moulding, an assembly or a kit substantially as herein described with reference to any one or more of the accompanying drawings.

In still a further aspect the present invention consists in an assembly of a kit as aforesaid, said assembly being of a kind substantially as hereinafter described with reference to any one or more of the accompanying drawings.

In yet a further aspect the present invention consists in a shoe and orthotic assembly where the orthotic component of the assembly is from a kit or assembly in accordance with the present invention in any of its aspects.

In yet a further aspect the present invention consists in a method of customising a moulded item as an orthotic insert for a shoe or other item of footwear, the method being performed substantially as herein described using a kit and/or assembly in accordance with the present invention in any of its aspects.

In another aspect of the invention the orthotic use of a wedge under one or both the medial rearfoot and/or the lateral forefoot of a contoured insole.

The preferments referred to hereinafter refer to any one or more aspects of the present invention.

Preferably the insert or pad for under the ball of the foot and/or under the lateral region of the heel is of a resilient and/or shock absorbing plastics material. Preferably said material is a foam material.

WO 2006/068513 PCT/NZ20051000334 Preferably said insert or pad or at least one of them is of a material softer than that of the insole.

The insole can be of any full, narrow or partial form and is preferably contoured at least for the general foot shape and/or footwear item it is likely to be used with.

It can be compression formed, moulded, sculpted, injection moulded or be made by a combination of sculpting and moulding or compression forming or injection moulding.

Preferably the insole is of a plastics material any suitable closed cell foam such as, by way of example, EVA or PE or PU (optionally with a laminated fabric topped) or coated upper surface)) and preferably has been compression moulded. Alternatively however, although this may detract from cost advantage, the insole can be formed from a sculpted or at least partly sculpted sheet or pre-mould of a suitable plastic.

Options for the material of at least one insert or pad include any compressible and/or shock absorbing and/or cushioning and/or resilient material that is or may be found suitable for the desired purpose PE and/or EVA or derivatives thereof). For example an EVA derivative foam. A preferred example is our SHOCKSTOP T M EVA derivative product, the ULTRASTOPTM EVA derivative of Ultralon Products (New Zealand) Limited, Christchurch, New Zealand or PORONTM cellular polyurethane.

The location, depression or pocket for the shock absorbing and compressible insert is under the ball of the foot. The more precise anatomical term of this location is "under the Metatarso-phalangeal joint of the 1st or great toe of the foot".

The effect of this location, depression or pocket and (with or without) the compressible and shock absorbing material supplied to be positioned under and/or in it is to allow the metatarsal to plantar flex more easily and thereby decrease the tension in the plantar fascia assisting the phalanx of the great toe to dorsiflex, increasing the height of the arch of the foot (enabling the windlass mechanism) and enhancing the stability and efficiency of the foot for propulsion.

The effect of a depression or pocket under the LATERAL (contact area) of the heel and the compressible and shock absorbing material supplied in it is to cushion and attenuate the shock of heel strike and lessen and decelerate the angular momentum of rearfoot pronation that is usually associated with the heel of the shod foot making contact with the ground. This feature helps to make walkiig or running while wearing footwear more similar to walking or running with bare feet. It is meant to reduce the shock of heel strike and the magnitude of the moment of force exerted on this area, which accelerates the rotation of the Calcaneus and velocity of pronation of the rearfoot (subtalar joint) that occurs during the contact period of WO 2006/068513 PCT/NZ20051000334 -11gait. When this lateral heel strike shock absorbing feature is accompanied by the pressure exerted by a wedge under the medial aspect of the heel, the synergistic effect is to lessen the velocity force and duration of pronation and reduce the muscular forces needed to resupinate the foot.

As used herein reference to a "wedge", "insert" or "pad" includes within its ambit a unitary member or an assemblage of unitary members. By way of example, a wedge could be of such a thickness as not always or ever to have a sufficient depth in the location therefor under the insole, i.e. it may require a separate choice of an appropriate depth packer.

Likewise for the flexible energy absorbing inserts or pads.

As used herein the term "and/or" includes "and" or or both.

As used herein the term following a noun, as is appropriate means the plural and/or singular forms of that noun.

Preferred forms of the present invention will now be described with reference to the accompanying drawings in which Figure 1 is a top view of a three quarter insole compression formed from a suitable, preferably closed cell foam, Figure 2 is an underside view of the three quarter insole of Figure 1 showing four locations on the base thereof, each preferably a depression formed in the undersurface to assist location with or without adhesive of the inserts, wedges, pads, etc., Figure 3 is a side view of the product of Figures 1 and 2, Figure 4 is the other side view, Figure 5 is an elevational view of the product of Figures 1 to 4 from the heel end, Figure 6 is an elevation view of the product of Figures 1 to 5 but from the fore end, Figure 7A is a repeat of Figure 2, Figure 7B shows the kit in a preferred form of the present invention, there being inserts or pads for two of the locations and wedges or pads for the remaining two locations if required, Figure 7C shows the insert pads and/or wedges appropriately located, Figure 8 shows the product of Figure 7 in front perspective, Figure 9 shows a full length insert from one side elevation, Figure 10 shows the other side elevation of the insole of Figure 9, Figure 11 is a front elevation of the product of Figure 9 and Figure 12 is a frontal perspective view of Figures 9 to 11, Figure 13 is another view of the product of Figures 9 to 12, WO 2006/068513 PCT/NZ20051000334 -12- Figure 14 for the product of Figures 9 to 13 is a similar view to that of Figure 2 and 7A for the three quarter insole, Figure 15 shows how if desired toe region locations (as depressions or otherwise) can be provided for, Figure 16 shows a different embodiment for that of figures 1 through 8 but which is nonetheless much the same. Figure 16 showing a right foot kit, Figure 17 shows a side view of the right foot kit as it would be provided alone or together with the left foot kit, the right foot kit showing how desirably but not necessarily the energy absorbing resilient insert or pad is pre-fitted under the ball region for the foot, Figure 18 is the other side view of the right foot kit of figures 16 and 17, Figure 19 is the top view of the kit of figures 16 to 18 in assembled form, Figure 20 shows the kit of figures 16 to 18 from below in a possible fully assembled form, Figure 21 is a front view of the assembly of figure 19 and Figure 22 is a rear view of the assembly of figures 19 to 21, Figure 23 is a side view of the assembly of figures 19 to 22, Figure 24 is the other side view of the assembly of figure 23, Figure 25 is the assembly of figures 19 through 24 when shown in perspective from below, Figure 26 is a view of a right foot kit as an alternative to the embodiment depicted as figures 9 to Figure 27 is the kit of figure 26 for the right foot from below showing how the insert or pad to support the ball of the foot has been pre-fitted prior to sale which is desirable, Figure 28 is a side view of the kit of figures 26 and 27, Figure 29 is a perspective view of the right foot kit of figures 26 to 28, Figure 30 is the top view of the kit of figures 26 to 29 when assembled, Figure 31 is the bottom view of the assembly of figure Figure 32 is a front view of the assembly of figures 30 and 31, Figure 33 is the rear view of the right foot assembly of figure 32, Figure 34 is the side view of the right foot assembly of figures 30 to 33, Figure 35 i the other side view of the assembly of Figure 34, and Figure 36 is a perspective view from the low of the right foot assembly of figures and Figure 37A is an elevational view from behind of the insole alone of Figure 16 to 18, WO 2006/068513 PCT/NZ20051000334 -13- Figure 37B is an elevation view from the side of the insole alone of Figures 16 to 18, Figure 37C is a bottom view of the insole alone of Figures 16 to 18, and Figures 38A to 38C show the same components assembled in a number of different ways, viz showing the lateral forefront wedge positioned in differently intrusive ways.

Where our use of wedges differs substantially from TALAR MADETM wedges and other existing products is that we are not advocating the use of measured degrees of wedge to control motion. We are using the wedge to apply pressure/force to the area and the amount or magnitude of this force/pressure can be varied by how much of the wedge you insert from the medial side. If one only inserts the wedge part way, the force/pressure will be less than if it is inserted all the way. We would compare this to the effect of using a wedge to split a log. The further in the wedge is driven the greater force/pressure it exerts on the wood. Whereas, makers of previous products have suggested varying the angle of the wedge, we are providing preferably only one angle, e.g. about 6°.

In the preferred form of the present invention the insole is preferably compression formed. A suitable foam includes EVA or PE foams but could equally be sculpted, moulded, injection moulded or hybridly formed foam other light weight plastics material suitable for the purpose.

Optionally the design of the insole can incorporate a thicker cross section under the medial side of the heel than the lateral side of the heel. This is generally referred to as an intrinsic varus wedge or "post". A suitable angle is from 2 to 80 and more preferably 3 or 4°.

The purpose of such a wedge form has been stated in the literature as being to exert a pressure or force to reduce the velocity ofpronation, to improve balance and stability and to reduce the muscular effort required to supinate the foot.

In the preferred form of the present invention the insole 1 is provided with locations 2 and 3 respectively for locating an energy absorbing resilient insert or pad 4 and 5 respectively under the lateral region of the heal and under the ball of the foot. Corresponding positions 2A and 3A exist in the variant shown in Figure 14 of the full size insole 4.

Other locations preferably also as depressions but not necessarily so are those 5 and 6 for location of wedges or pads (preferably wedges) 7 and 8 respectively.

Preferably each of the members 7 and 8 is a wedge having the greatest depth more outwardly so hs to achieve the purposes previously stated.

Preferably the inserts 4 and 5 have no wedging characteristic but are merely inserts to provide a depressible support owing to the depressibility of the material and the energy absorption thereof thereby to achieve the outcomes stated.

WO 2006/068513 PCT/NZ20051000334 -14- The pads or inserts can be of PE, EVA or PU, or derivatives or mixtures thereof. A preferred material for each of components 4 and 5 is our aforementioned SHOCKSTOPTM EVA derivative foam product, ULTRASTOPTM EVA derivative foam, or PORON T cellular polyurethane.

The wedges are harder than the inserts or pads 4 and 5 and can be of compressed, sculpted and/or injection moulded PE, EVA or PU, or mixtures or derivatives thereof.

Once an appropriate location for a wedge with or without any trimming or relocation has been established it can be fixed by a suitable (preferably flexible) contact adhesive.

Likewise inserts 4 and 5 can be fixed by a suitable adhesive. Any suitable contact adhesive product, which is capable of adhering to and bonding together pieces of plastic foam material may be used, either in the form of double sided adhesive tapes or directly applied by any other means to the surfaces to be bonded together. In this instance, the preferred method of bonding components together is by way of tape coated with contact adhesive on either side. However, in some cases, this form of bonding may not be sufficiently durable in use and more permanent bonding with heat activated contact adhesives may be recommended.

In some forms of the present invention the product will be used solely with inserts 4 and 5 and not 7 and 8 whilst in others it will be used with 7 and 8 as well or one or other of 7 and 8.

Our existing self or professional mouldable orthotic which is marketed under our

FORMTHOTICS

T M brand has a Shore A scale hardness of 35 and this corresponds to JIS C hardness of around Insofar as the materials of the present invention are concerned, the insole/orthotic/arch support material preferably of EVA or PE) preferably has a hardness of JIS C 30 to A range of various densities and colours can be provided. If only two in the range, an example is a JIS C hardness of about 50 for a softer model and about 70 for a harder model.

Such products (preferably fabric topped) could be offered in different colours for different densities.

The shock absorbing inserts, if of the SHOCKSTOP T M material referred to, preferably has a hardness range JIS C of 20 to 60. Most preferably the JIS C hardness is from 40 to and preferably is softer than the material of the arch support itself.

The thickness of the material under the medial side of the forefoot from the apex of the arch to the ball of the foot is considerably less than is found in many previous orthotic products. This is intentional and is also related to allowing the windlass mechanism to establish easily and without impediment.

WO 2006/068513 PCT/NZ20051000334 The wedges and/or any packers therefor are preferably formed by compression from EVA. The range of hardness for the wedges is JIS C 50 to 100 but with a preferred hardness of the order of about JIS C Other preferred embodiments respectively to those of Figures 1 to 8 and Figures 9 to 15 but in respect of the right foot kit and the kit assembly only are shown in Figures 16 to and 26 to 36 respectively.

Wedges or other parts of the kit 11 and 12 respectively (see Figures 16 and 29 respectively) are used as required. Already inserts 13 or 15 and 14 or 16 have been pre-fitted.

Pads 15 and 16 have been fitted to the insole 10. The inserts 13 and 15 are under the ball of the foot or the medial side of the fore foot whilst the inserts 14 and 16 are for the lateral part of the heel or rear foot.

The additional components 11 and 12 respectively are used for the other zones as previously discussed. In the case of Figure 25 wedges 17 and 18.

Whilst some of the drawings Figures 25 and 36) show a wedge 19) inserted under the big toe (for example, as a replacement of or addition to a PORONTM cellular polyurethane pad) this is a rare requirement. Such a wedge is used only in those rare cases where a patient requires a very small force to establish the windlass or requires a slight wedge in this area to improve balance. This is very uncommon.

A similar arrangement is shown in figure 36 for the full or near full insole.

Figures 37A, 37B and 37C show one embodiment of the insole where ridges 20 and 21 are provided to define the regions where the wedges are to be attached.

It can be seen therefore how a moulded or otherwise formed insole of a material that is somewhat incompressible and which preferably may carry a fabric interface for the wearer's foot can have one or more soft insert provided. Indeed where desired such a soft insert can be rendered wedge shape by the addition of an additional or another kit provided attachment. Wedges of different shapes can be provided to customize for a particular wearer by being located in the zones of the lateral region of the forefoot and the medial region of the rear foot or heel.

Persons skilled in the art will appreciate the options that a product in accordance with the present invention provides for self customization of a high volume moulded insole to be pr6dVided in a kit form. The ridges 20 and 21 may act as a guide for the attaching of the wedges during this self customization process.

WO 2006/068513 PCT/NZ2005/000334 -16- Figures 38A to 38C show a wedge for the forefoot lateral position fixed in a number of different ways thereby to affect the correct force that will be applied. The wedge 17 can be trimmed if required after fixing.

Analogously, the medial rearfoot wedge 18 instead, or as well as 17, can be fixed in other than the degree of intrusiveness shown in Figures 38A to 38C.

It is to be noted, as is usually the case, the pad 13 is not carrying a wedge.

As previously stated the purely biomechanical model is deficient and not scientifically validated.

Our model ("Baycroft Model") is compatible with biomechanical principles but also addresses other and perhaps more important factors relating to foot and leg function. These include: 1. Neurological aspects such as proprioception, balance and neuromuscular adaptation to changes in pressure on the sole of the foot and also alterations in the patterns of stimulation of muscles.

2. Muscle function. The movement of structures and components of the body is controlled by the action of muscles and this is not sufficiently appreciated in the biomechanical theory. Various muscles exert the forces required to supinate the subtalar joint and to change the position and shape of the foot during gait. The magnitude of these muscular forces and of the resultant strain exerted on structures by the resistance to these movements are estimated by the Supination resistance and force to activate the windlass mechanism observations ("Jack's Test"). Reductions in the resistance to supination and activation of the windlass therefore reduce the work of the muscles and strain in the structures of the foot and leg.

This model is applied to clinical practice by using 6 tests of foot and leg function: 1. Alignment. This relates to the skeletal and biomechanical components of function.

The Skeletal elements of most people's bodies are not aligned in a biomechanically "ideal" way, yet these people are normal and function well for most of their lives. Malalignments are widely recognized as a causative factor in Patello Femoral joint Dysfunction. Orthotics can create small changes in functional alignment (static and dynamic), which result in the redirection of force vectors away from irritated tissues and onto stronger tissues that are better able to withstand these forces. This is the basic biomechanical effect of Foot Orthoses.

2. Subtalar Motion. The Subtalar and other joints of the foot are no different from other joints in the body. They have a similar structure, physiology and function. Their movement is WO 2006/068513 PCT/NZ2005/000334 -17controlled by muscles and they develop restrictions of motion, which can and should be mobilized when discovered. The currently popular Orthotic Theory holds that some physiological movements of these joints (Pronation and Supination) are undesirable or "pathological". This contradicts all accepted principles of Musculoskeletal medicine. The joints of the Foot should be regarded as any other peripheral joints. Full range of Motion should never be restricted and restrictions should be mobilized, especially if Orthotics are going to be prescribed.

3. Balance. The soft tissue structures of the foot are richly supplied with Neuroreceptors. The pattern of stimulation of these receptors determines reflex motor activity such as proprioception. Balance is related to proprioceptive function and can be clinically assessed by standing on one leg and then closing the eyes. Appropriately adjusted Foot Orthoses are the quickest and best way to improve proprioception and balance because they immediately alter the pattern of neuroreceptor stimulation and afferent neural activity in the lower limb.

4. Forefoot Stability. The heel should lift smoothly and easily from the ground and the forefoot should become a stable platform for propulsion. This is assessed by asking the patient to stand on one foot and then rise up onto the toes (eyes open please). Most patients find this difficult, become laterally unstable and hence are very susceptible to inversion anlde sprains.

A small lateral forefoot Post or wedge applied to the orthotic improves the ease and stability of rising onto the toes and thereby improves propulsion.

Supination Resistance. This simple and scientifically valid test was discovered by Craig Payne, a Podiatrist at Latrobe University in Melbourne. (His publications on supination are listed at www.latrobe.edu.au/podiatry/craig.html). People vary greatly in the force that must be applied under the medical arch of the foot to supinate the Subtalar Joint. Patients with a high supination resistance have a more oblique Subtalar Joint axis. The force required to supinate the Subtalar Joint in function is produced by the muscles of the foot and leg and the strain in these muscles is related to the force they must exert. Orthotics with an appropriate medial rearfoot post or wedge can significantly reduce the resistance of the Subtalar Joint to supination relieving the strain in these commonly injured muscles and related structures.

6. Jack's Test. This involves passively dorsiflexing the great toe and has been described S by Payne to be a reliable assessment of the force required to activate the "Windlass Mechanism" of the foot. A windlass is a cylinder with a cable wrapping around it and the use of this term refers to the way the digital extensions of the Plantar Fascia wrap around the MTP joints of the toes. The higher the force required to activate the windlass the higher will be the WO 2006/068513 PCT/NZ2005/000334 -18strain in the plantar fascia, Achilles' Tendon and other structures of the foot and leg.

Difficulty rising onto the toes, in the Forefoot Stability Test, usually indicates that a large force is required to activate the windlass. A depression under the ball of the great toe and/or appropriate lateral forefoot wedge will allow the "windlass" to establish more easily.

Claims (16)

1. 2. A kit of claim 1 wherein the insert or pad of each of the medial region of the fore foot and the lateral region of the rear foot region is pre-fitted.
2. 3. A kit of claim 1 or 2 wherein at least one wedge is of fixed wedge angle and the intrusion extent of its location will determine the corrective force being applied.
3. 4. A kit of claim I wherein the wedge angle is about 6°. A kit of claim I wherein both wedges are of wedge angle about 6°.
4. 6. A kit of claim 1 wherein at least one wedge has a wedge angle from 3° to 90 or ranging from 30 to 9°.
5. 7. A kit of claim 1 wherein the insole is for part only of the foot.
6. 8. A kit of claim I wherein the insole is for at least substantially all of the foot.
7. 9. A kit of claim 1 wherein raised lines on the sole of the insole define a zone for each wedge.
8. 10. A kit of claim 1 wherein a depression in the sole of the insole defines one zone for a said wedge.
9. 11. A kit of any one of the preceding claims adapted to applying or altering forces that act on the foot.
10. 12. A kit of any one of the preceding claims adapted to be used to improve proprioception, stability and balance when standing with the entire foot in contact with the surface beneath it.
11. 13. A kit of any one of the preceding claims adapted to reduce the moment of force acting on the posterolateral border of the heel at heel strike/contact and/or that Amended Sheet IPEA/AU pCT1NZ2005000 3 3 4 SReceived 2 5 August 2006 accelerates the angular momentum of pronation of the subtalar joint without reducing the physiological range of motion of pronation of the subtalar joint.
12. 14. A kit of any one of the preceding claims wherein the features and components of the forefoot area are there to improve stability and balance when rising onto and standing on the toes during the propulsive period of gait. A kit of any one of the preceding claims wherein wedges are used, or are to be used, as a means of applying force to particular sites on the sole of the foot and the amount of force is to be dependent on the depth of intrusion of the wedge under the insole.
13. 16. A kit of any one of the preceding claims are to be used as part of an interactive clinical and practical method for altering the function of the foot and leg.
14. 17. A kit of any one of the preceding claims packaged with instructions as to its assemblage and use.
15. 18. In combination and as a kit, at least one kit of any one of the preceding claims for one foot and at least a contoured insole for the other foot.
16. 19. A combination of claim 18 wherein there are at least substantially two said kits, one for each foot. A method of fitting an orthotic to improve the function of the foot and leg, said method involving a kit in accordance with any one of the preceding claims and involves in respect of the moulded insole, prior to and/or during fitting into an item of footwear, providing or having a pad under the media region of the forefoot, the ball of the foot region and/or at least part of the big toe region of the insole, and providing or having a pad under the lateral region of the heal or rearfoot region of the insole, locating a wedge under the medial region of the rearfoot region of the insole, and locating a wedge under the lateral region of the forefoot region of the insole. TOTAL P.1 Amended Sheet IPEA/AU