FIELD OF THE INVENTION
This invention relates to orthotic inserts and to a method of manufacturing orthotic inserts.
BACKGROUND ART
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
The human foot is a complex structure made up of 28 bones held together by soft tissue, muscles, ligaments and tendons.
Orthotic inserts are used to provide additional support for the feet of a wearer, particularly in circumstances where the wearer requires a degree of bio-mechanical support and control.
Orthotic inserts can range from simple foam, leather, cork, or sponge rubber arch supports that can be purchased over the counter, through to relatively sophisticated custom made inserts. Typically, the more sophisticated orthotic inserts are relatively expensive and are produced on a custom made basis in accordance with detailed prescriptions provided by the examining doctor.
The primary function of an orthotic insert is to control any excessive pronation and supination that a person may experience as his or her foot strikes the ground during walking or running. Pronation is the flattening or rolling inward of the foot as the foot strikes the ground, whilst supination is the rolling outward of the foot during walking or running. If either of these motions become excessive, damage to the knees, ankles and feet can occur.
Known orthotic inserts rely upon the contouring of the upper surface of the insert to provide the necessary degree of support and control for the wearer. However, in certain circumstances this may not provide sufficient comfort for the wearer.
It is therefore an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.
SUMMARY OF THE INVENTION
To this end, a first aspect of the present invention provides a heat mouldable orthotic insert having a first and second portion, wherein said second portion is formed of a material of higher resistance to deformation than said first portion.
Preferably, both the first and second portions of the orthotic insert are formed from resilient material, with the second portion being formed from a resilient material of higher resistance to deformation than said first portion.
Preferably, the second portion is formed from a material of higher density than the material from which the first portion is made.
Preferably, said first and second portions of the orthotic insert are formed from heat mouldable ethyl vinyl acetate.
Preferably, said first and second portions of the orthotic insert are joined by bonding. More preferably, said first and second portions are joined together by gluing.
Preferably, the second portion is adapted to provide support for the heel region of a person's foot. In a further preferred embodiment, the second portion is adapted to provide support for the heel and arch regions of a person's foot.
In one particularly preferred embodiment, the second portion has a substantially U- or J-shaped configuration which extends partially around the periphery of the insert corresponding to the heel and arch regions of a person's foot.
Unless the context clearly requires otherwise, throughout the description and the claims, the words `comprise`, `comprising`, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".
Advantageously, the orthotic insert according to the present invention is able to be heat moulded to the contours of the underside of a person's foot in the correct biomechanical position whilst standing in a weight bearing position.
Advantageously, in one particularly preferred embodiment the present invention provides an orthotic insert which provides improved support and comfort for a person's foot around the heel and arch areas.
A second aspect of the present invention provides a method of producing an orthotic insert comprising forming a first portion of the insert, forming a second portion of the insert from a material of higher resistance to deformation than said first portion of the insert, and joining said first and second portions together to form the insert.
Preferably, the first portion of the insert is formed by moulding. More preferably, the first portion of the insert is formed by heat moulding.
Preferably, the second portion of the insert is formed by moulding. More preferably, the second portion of the insert is formed by heat moulding.
Preferably, the said first and second portions are joined together by means of bonding. More preferably, the first and second portions are joined together by gluing.
In one particularly preferred embodiment, the second portion has a substantially U- or J-shaped configuration which extends partially around the periphery of the insert corresponding to the heel and arch regions of a person's foot.
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