Self-adhering friction reducing liner and method of use

Abstract

A patch of low friction materials, such as a film of polytetrafluoroethylene is sized to provide an area of low friction support for a portion of a human body relative to an object such as a shoe or prosthetic socket. The patch can be lined with foam, or preferably, a stretch fabric so that it will fit around irregular contours of the shoe, or socket, or the skin itself. The patches reduce shear trauma in critical load areas. After identifying regions of high loads, the method comprises applying the patches as needed to avoid sores, calluses, blisters and abrasions.

Description

BACKGROUND OF THE INVENTION[0001] The present invention relates to the use of very low friction material formed into patches or pieces and adhered to the skin or to a surface in contact with the skin (or immediately adjacent material such as a sock) to lower the magnitude of tangential traction of the surface in contact with the skin. The material reduces the likelihood of abrasion, trauma and ulceration-in localized areas.[0002] In the prior art, there have been efforts to reduce the co-efficient of friction of materials in load bearing contact with the skin, such as the surface of a lining of a shoe, which slides against a stocking. Also the regions where a limb prosthesis is in load bearing contact with a residual limb have been extensively considered for ways of reducing problems. The co-efficient of friction of smooth leather varies, depending on the moisture content, and when it gets wet can be quite high in friction. Moleskin patches have been sold and used for covering corns...

AI Technical Summary

Benefits of technology

[0011] The present invention relates to providing a layer of material that has a very low friction outer surface in both dry and wet conditions to provide an interface with a surface that normally would support the skin either directly or through a cloth covering, such as a sock fabric. In the usual situation, the surface loading or bearing on the skin may be the inner surface of an orthosis, the socket surface of a prosthesis, or inner surfaces of a shoe, especially insoles, but also other inner surfaces. The layer of low-friction material is adhered, preferably, to the surface of the object that bears on the skin and faces the skin, although applying the layer with an adhesive directly on the skin in the affected area with the low friction surface facing the support is also contemplated. The purpose of the low friction material is to lower the magnitude of tangential tractions that the surface of the object can exert against the skin.

[0012] The use of intervening layers is contemplated in the present invention, so a sock or sheet placed between the low friction pad and the skin does not adversely affect the performance.

Problems solved by technology

High shear stresses may cause damage in a single cycle.

Low shear stresses may cause tissue damage when the number of cycles is great.

Shear strain is by its very nature very distortional and, when it exceeds certain levels, results in the tearing of biological tissues such as blood capillaries and interface (skin-subcutaneous) layers.

However, how and when excessive shear stresses / strains occur and how they damage tissue are hard to visualize.

Shear stresses and how they vary over a given area (and vary with time) are very hard to measure; much harder than it is to measure normal pressure.

In addition to the visualization and measurement difficulties just mentioned, there is the fact that few people have better than a vague qualitative awareness of how something called the "coefficient of friction" (C.F.) relates to blisters, abrasions, and calluses.

Examination and knowledge of products on the market indicate that the opportunities for reducing callusing, blistering and abrasions by friction management has been almost entirely unappreciated by designers of shoes, orthoses, prostheses, and many other objects that come in repeated or prolonged contact with the human body.

Foam products are used to line prosthetic sockets, orthoses, and shoe insoles and represent a particularly poor material from the standpoint of friction management.

Damp skin and sock material literally sticks to such foams.

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