AU2006206055B2

AU2006206055B2 - Orthotic device

Info

Publication number: AU2006206055B2
Application number: AU2006206055A
Authority: AU
Inventors: Luke Douglas Sinclair; Melissa Jane Sinclair
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-01-17
Filing date: 2006-01-17
Publication date: 2010-05-13
Anticipated expiration: 2026-01-17
Also published as: AU2006206055A1

Description

WO 2006/074528 PCT/AU2006/000055 ORTHOTIC DEVICE FIELD OF THE INVENTION The present invention relates to an orthotic device. The present invention also relates to a method for producing an orthotic device. 5 BACKGROUND TO THE INVENTION The human foot is a complex structure made up of a number of bones that are held together by various muscles, ligaments and tendons. Although the structure of the foot generally copes exceedingly well with the stresses and forces imposed on the foot by exercise and other everyday activities, unfortunately, a large number of people suffer foot problems. 10 Some such foot problems include heel spurs, plantar fasciitis, sesamoiditis, fallen arches, flat feet, excessive pronation or excessive supination. This list is not exhaustive. Orthotic devices have been used for many years to treat foot problems. Orthotic devices are worn inside the shoe to control abnormal foot function and/or to accommodate painful areas of the foot. Orthotic devices can range from very simple off the shelf devices that 15 merely provide padding for the foot through to specially designed and shaped devices that are prepared by qualified podiatrists. Properly designed foot orthotics may compensate for impaired foot function by controlling abnormal motion across the joints of the foot. Custom made foot orthotics are typically made from rigid materials, especially hard plastics and carbon-fibre composites. Custom made orthotics are normally based upon a 20 plaster impression of the feet and modified in accordance with the evaluation of foot problems made by a podiatrist. There are also a range of off the shelf orthotic devices that are typically made from a foamed rubber or resilient plastics material. Such off the shelf orthotic devices normally have a pre-moulded shape that includes an upper surface that has a heel cup and a longitudinal arch 25 raise. The heel cup controls the position of the foot in the shoe and the longitudinal arch raise provides enhanced arch support. Such orthotic devices may also include, in some instances, a metatarsal raise to control the position of the metatarsals. These orthotic devices, by virtue of being made from resilient materials, provide a degree of support and control to the foot whilst also offering increased cushioning to the foot.

WO 2006/074528 PCT/AU2006/000055 -2 The applicant does not concede that the above prior art forms a part of the common general knowledge in Australia or elsewhere. Throughout this specification, the term "comprising" and its grammatical equivalents are to be take to have an inclusive meaning unless the context clearly indicates otherwise. 5 BRIEF DESCPPTION OF THE INVENTION In a first aspect the present invention provides an orthotic device for placement inside footwear, the orthotic device having a shaped body having an upper surface that in use contacts a foot of a user and a lower surface that in use lies on an inner part of the footwear, the shaped body including a longitudinal arch raise and a heel cup, the device further having a gel insert 10 located in the heel cup region, the gel insert extending in vertical extent from the lower surface to the upper surface. Preferably, the shaped body is made from a resilient material. For example, the shaped body may be made from a polyurethane foam. Alternatively, the shaped body could be made from an EVA material. It will also be appreciated that other resilient materials used in the 15 manufacture of orthotic devices may also be used in the present invention. The skilled person will readily be able to identify and source appropriate materials for use in making the shaped body for use in the present invention. The gel insert is located in the heel cup region of the orthotic device. The gel insert is suitably a silicon gel or a thermoplastic rubber, such styrene-ethylene-butylene-styrene (SEBS) 20 thermoplastic elastomer or other thermoplastic elastomer. The gel insert suitably includes a gel material surrounded by a flexible casing material. The flexible casing material acts to retain the gel material in position. The flexible casing material is most suitably a flexible plastic, such as an elastomer. The flexible casing material may be, for example, thermoplastic polyurethane. The skilled person will readily be able to source appropriate gel inserts for use in 25 the present invention. The shaped body is suitably formed by a moulding technique. Such moulding techniques are well known to persons skilled in the art and need not be described further. The shaped body is formed such that it has at least a longitudinal arch raise and a heel cup. The upper surface of the shaped body comes into contact with the foot of a user and 30 suitably provides orthotic correction to the foot of the user.

WO 2006/074528 PCT/AU2006/000055 -3 In some embodiments, the shaped body may include a plurality of obliquely extending depressions extending across at least a part of the longitudinal arch raise. The obliquely extending depressions may comprise a series of obliquely extending lines, with each line being spaced from the other lines. The lines suitably extend from the vicinity of one side edge of the 5 orthotic device to the opposed side edge of the orthotic device. The plurality of obliquely extending depressions assist in increasing the flexibility of the orthotic device in the region of the longitudinal arch raise. This provides enhanced comfort to the user of the device. The obliquely extending depressions also assist in dissipating perspiration. The plurality of obliquely extending depressions suitably extend at an angle of between 10 200 and 70' to a longitudinal axis of the orthotic device. The depressions may be spaced apart by between 5 and 20mm, more suitably between 7 and 15mm. The gel insert is located in the heel cup region of the orthotic device. The gel insert provides increased shock absorption to the heel during walking or running. In some embodiments, the gel insert may have an elongated shape. For example, the 15 gel insert may include a rear edge that follows a contour of the rear of the shaped body, with a side portion of the gel insert generally following but spaced from a side edge of the orthotic insert, with another side of the gel insert extending from the rear portion of the gel insert to join to a front edge of the first side portion. Alternatively, the gel insert may be of generally tear drop shape. 20 It has been found that, by making the gel insert in the shapes as described above, more of the heel region of the user's foot comes into contact with the gel insert during walking to thereby help absorb shock across a larger extent of the heel region of the foot of the user. This provides enhanced comfort. The gel insert suitably does not extend into the longitudinal arch raise of the shaped 25 body. In this fashion, the arch support provided by the longitudinal arch raise is not compromised by the presence of a flexible gel insert in the longitudinal arch raise region. The gel insert extends in vertical extent from the lower surface to the upper surface of the shaped body. Most suitably, the lower surface of the gel insert comprises part of the lower surface of the orthotic device and the upper surface of the gel insert comprises part of the upper WO 2006/074528 PCT/AU2006/000055 -4 surface of the orthotic device. This allows use of a gel insert having a maximum possible thickness in the device to thereby enhance the shock absorption effect of the gel insert. The gel insert is suitably made as a separate component that is subsequently joined to the shaped body. To facilitate this embodiment, the shaped body may be provided with a hole 5 through the heel cup region, with the gel insert being positioned in the hole and then being joined to the shaped body. The gel insert may be joined to the shaped body by using an appropriate plastics welding technique or by the use of a suitable adhesive. The hole in the shaped body may be formed by cutting or stamping. Alternatively, the shaped body may be moulded with the hole being pre-formed in the heel cup region of the shaped body during 10 moulding. In another embodiment, the shaped body is provided with a recess formed underneath the longitudinal arch raise. This recess reduces the material requirements in manufacture. Further, the recess also acts to reduce the thickness of the device in the longitudinal arch raise region to thereby improve the flexibility of the device. 15 The upper surface of the shaped body may be covered with a fabric material, especially a non-woven fabric material. The fabric material provides enhanced comfort for the user it also increases friction between the user's foot or sock and the upper surface of the device. In a second aspect, the present invention provides a method for forming an orthotic device as described with reference to the first aspect of the invention, the method comprising 20 moulding a shaped body, forming a hole in the heel cup region of the shaped body, inserting a gel insert into the hole and joining the gel insert to the shaped body. The hole may be formed in the shaped body as part of the moulding process. Alternatively, the hole may be formed by cutting or stamping. The gel insert is suitably joined to the shaped body by use of an appropriate plastics 25 welding technique or by use of a suitable adhesive. The gel insert is suitably joined around its periphery to the shaped body. More suitably, the gel insert is joined to a lower surface of the shaped body. The gel insert may comprise an envelope of plastic material having a gel material sandwiched there between, with the envelope of plastic material including a peripheral edge portion extending outwardly from the gel 30 material. The peripheral edge portion suitably overlaps with the peripheral portion of the WO 2006/074528 PCT/AU2006/000055 -5 shaped body around the hole and the peripheral edge portion of the gel insert is then joined to the shaped portion. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top view of an orthotic device in accordance with an embodiment of the 5 present invention; Figure 2 is a bottom view of the orthotic device shown in figure 1; Figure 3 is a side view, taken from an outer side, of the orthotic device shown in figure 1; Figure 4 is a side view, taken from an inner side, of the orthotic device shown in figure 10 1; Figure 5 is a cross-sectional view taking along line A to A in figure 1; and Figure 6 is a cross-sectional views taking along line B to B in figure 1. DETAILED DESCRIPTION OF THE DRAWINGS The drawings accompanying the specification have been provided for the purpose of 15 illustrating a preferred embodiment of the present invention. Thus, it will be understood that the present invention should not be considered to be solely limited to the features as shown in the accompanying drawings. The orthotic device 10 shown in figures 1 to 4 includes a shaped body 12 made from a polyurethane foam material. The polyurethane foam may have, for example, a hardness of 60 20 and a specific density of 0.4 (equating to 400gk/m 3 . The shaped body 12 includes a heel cup region 14 and a longitudinal arch raise 16 (best shown in figures 3 and 4). The longitudinal arch raise 16 provides arch support to the foot of a user of the orthotic device. The orthotic device 10 further includes a gel insert 18 that is located in the heel cup region of the orthotic device. The gel insert may comprise a gel material made from, for 25 example, styrene-ethylene-butylene styrene thermoplastic elastomer (SEBS) encased in a skin made from a thermoplastic polyurethane. Typical properties of the SEBS and the thermoplastic polyurethane may be as follows: Table 1: Typical Properties of thermoplastic polyurethane: WO 2006/074528 PCT/AU2006/000055 -6 Property Thermoplastic Polyurethane (TPU) [Structure | Amorphous Hardness (Shore) |60 -95 Density (g/cm 3 ) 1.13 - 1.35 Ultimate Tensile 4,000 to 10,000 Strength (psi) Ultimate Elongation (%) 300-800 [Tear Strength (pli) 300 - 700 Utilisation Temperature -780 - 1150 (.C) ,[Melting Point ( 0 C) | 2000 -2307 Chemical Resistance - Acids Good - Alkalis Good - Solvents Good UV Resistance Good Abrasion Resistance |_Excellent R Sealable | Yes Thermoformable Yes Transparency | Translucent Table 2: Typical Properties of SEBS Property SEBS Density (g/cm 3 ) 0.9 - 0.94 Hardness (shore) 0 OA- 50D FTensile Strength (MPa) 6 Linear Expansion (/ C x 10 ) 16 Elongation at Break (%) 800 Working Temperature ('C) -500~800/150 Melting Temp. Range ( 0 C) 2000 - 2400 5 The skilled person will recognize that other materials may also be used in the gel insert. The gel insert 18 includes a rear edge 20 that generally follows the contour of the rear edge of the heel cup region 14. The gel insert further includes a side edge 22 that extends forwardly from the rear edge. Side edge 22 is spaced from but generally follows the side edge 24 of the shaped body 12. The other side 26 of the gel insert converges into the leading end of WO 2006/074528 PCT/AU2006/000055 -7 side edge 22. In this fashion, the other side edge 26 of gel insert 18 does not extend into the longitudinal arch raise 16 of the orthotic device 10. In this way, the gel insert does not comprise the support provided by the longitudinal arch raise 16. As best shown in figure 5, the gel insert 18 has an upper surface 28 and a lower surface 5 30. The upper surface 28 of gel insert 18 forms part of the upper surface of the orthotic device 10. Similarly, the lower surface 30 of the gel insert 18 forms part of the lower surface of the orthotic device 10. The gel insert 18 is suitably joined to the shaped body 12 by use of a plastics welding technique (such as ultrasonic welding) or by use of a suitable adhesive. In order to join the gel adhesive to the shaped body, a hole is formed in the shaped body 12. As 10 best shown in figure 5, the lower edge of the hole includes a shoulder 32. The shoulder 32 extends around the periphery of the hold in the shaped body. The shoulder 32 provides a surface which overlies a peripheral of the gel insert, with the shoulder surface and the underlying peripheral of the gel insert providing a convenient site for joining. As can be best seen in figures 1 and 3, the upper surface of the orthotic device 10 15 includes a series of obliquely extending depressions, some of which are denoted by reference numeral 34. The obliquely extending depressions 34 are obliquely extending in that they are oriented at an oblique angle relative to the longitudinal axis of the orthotic device. The obliquely extending depressions 34 suitably are made by forming a series of obliquely extending lines in the shaped body 12. These obliquely extending lines assist in increasing the 20 flexibility of the longitudinal arch raise portion of the orthotic device, which acts to increase the comfort of the orthotic device whilst still retaining the support for the foot required in the longitudinal arch rise. As best shown in figure 2, the lower surface of the shaped body 12 includes a series of generally longitudinally extending depressions, such of which are denoted by reference 25 numeral 36. These depressions 36 provide greater lateral flexibility to the orthotic device, which further increases the comfort without compromising the support of the device. The depressions 36 may, for example, be from 1 to 5mm wide and from 1 to 3mm deep. The orthotic device 10 further includes a recess 38 that is formed in the shaped body underneath the longitudinal arch rise. Recess 38 acts to minimize the amount of material required in the 30 production of the shaped body 12. It also makes the device lighter and more flexible, both of which increase comfort of the device.

WO 2006/074528 PCT/AU2006/000055 -8 The device shown in figures 1 to 6 is generally referred to as a "%" orthotic device in that the device extends under about % of the length of the foot. However, full foot orthotic device also fall within the scope of the present invention. As best shown in figure 5, the heel cup region includes a raised periphery 40, as will be 5 known to persons skilled in the art. The upper surface of the shaped body 12 is suitably covered with a fabric material, especially a non-woven fabric material. The fabric material is suitably adhered to the shaped body in a manner conventional in this art. The orthotic device of the present invention provides an orthotic device that does not 10 require special customization by a trained podiatrist. The orthotic device can provide good orthotic support to correct foot or posture problems whilst also providing good comfort levels for the user. The shaped body is suitably shaped such that the orthotic support provided by the longitudinal arch raise and the heel cup is pre-formed into the shaped body. The shaped body suitably retains its shape during wear by the user, although it will be appreciated that some 15 compaction will occur following extended use of the device. The slightly oblong teardrop shape of the gel insert 18 shown in figures 1 and 2 allows for a greater area of contact between the heel of the user and the gel insert, which acts to improve shock absorption under the heel. The shape of the gel insert also ensures that the gel insert does not impinge upon the longitudinal arch raise thereby ensuring that the orthotic 20 support resulting from the longitudinal arch raise is not compromised. Figures 1 to 6 show an orthotic device in accordance with an embodiment of the present invention for use with the right shoe of a user. It will be appreciated that the device will be sold in pairs which each pair containing a right foot orthotic and a left foot orthotic. Those skilled in the art will appreciate that the present invention may be susceptible to 25 variations and modifications other than those specifically described. It will be understood that the present invention encompasses all such variations and modifications that fall within its spirit and scope.

Claims

1. An orthotic device for placement inside footwear, the orthotic device having a shaped body having an upper surface that in use contacts a foot of a user and a lower surface that in use 5 lies on an inner part of the footwear, the shaped body including a longitudinal arch raise and a heel cup, the device further having a gel insert located in the heel cup region, the gel insert extending in vertical extent from the lower surface to the upper surface.

2. An orthotic device as claimed in claim 1 wherein the gel insert comprises a gel material surrounded by a flexible casing material. 10

3. An orthotic device as claimed in claim 1 or claim 2 wherein the gel insert has an elongated shape.

4. An orthotic device as claimed in claim 3 wherein the gel insert has a rear edge that follows a contour of the rear of the shaped body, with a side portion of the gel insert generally following but spaced from a side edge of the orthotic insert, with another side of the gel 15 insert extending from the rear portion of the gel insert to join to a front edge of the first side portion.

5. An orthotic device as claimed in claim 3 wherein the gel insert is of generally tear drop shape.

6. An orthotic device as claimed in any one of the preceding claims wherein the gel insert 20 does not extend into the longitudinal arch raise of the shaped body.

7. An orthotic device as claimed in any one of the preceding claims wherein the shaped body includes a plurality of obliquely extending depressions extending across at least a part of the longitudinal arch raise.

8. An orthotic device as claimed in claim 7 wherein the obliquely extending depressions 25 comprise a series of obliquely extending lines, with each line being spaced from the other lines.

9. An orthotic device as claimed in claim 8 wherein the lines extend from a vicinity of one side edge of the orthotic device to the opposed side edge of the orthotic device. WO 2006/074528 PCT/AU2006/000055 -10

10. An orthotic device as claimed in claim 7 or claim 8 wherein the plurality of obliquely extending depressions extend at an angle of between 20' and 700 to a longitudinal axis of the orthotic device and are spaced apart by between 5 and 20mm.

11. An orthotic device as claimed in any one of the preceding claims wherein the shaped body 5 is provided with a recess formed underneath the longitudinal arch raise

12. An orthotic device as claimed in any one of the preceding claims wherein the shaped body is made from a resilient material.

13. An orthotic device as claimed in claim 12 wherein the shaped body is made from a polyurethane foam or an EVA material 10

14. An orthotic device as claimed in any one of the preceding claims wherein the gel insert comprises a gel material surrounded by a flexible casing material.

15. An orthotic device as claimed in claim 14 wherein the gel material is a silicon gel or a thermoplastic rubber and the flexible casing material is a flexible plastic.

16. A method for forming an orthotic device as claimed in any one of the preceding claims, the 15 method comprising moulding a shaped body, forming a hole in the heel cup region of the shaped body, inserting a gel insert into the hole and joining the gel insert to the shaped body.

17. A method as claimed in claim 16 wherein the hole is formed in the shaped body as part of the moulding process. 20

18. A method as claimed in claim 16 wherein the hole is formed by cutting or stamping.

19. A method as claimed in claim 16 wherein the gel insert is joined to the shaped body by use of a plastics welding technique or by use of an adhesive.

20. A method as claimed in claim 16 wherein the gel insert comprises an envelope of plastic material having a gel material sandwiched there between, with the envelope of plastic 25 material includes a peripheral edge portion extending outwardly from the gel material and wherein the peripheral edge portion overlaps with the peripheral portion of the shaped body around the hole and the peripheral edge portion of the gel insert is joined to the shaped portion.