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

0019] The patches of the present invention offers an easy way to accomplish "friction management". The surfaces that a shoe, orthosis, or prosthesis present to the skin vary as to their function and as to the tissue trauma risk they present. It is also true that some areas of the anatomy within a shoe, prosthesis, or orthoses are at greater or lesser risk because of the level of peak forces and/or the amount of soft tissue interposed between skin and bone. Some parts of an orthosis bear only slightly or not at all against the corresponding skin surface. Other parts bear very firmly in order to provide maximum orthopedic support, correction, or weight bearing. Still other surfaces such as the supra-condylar parts of a BK (lower leg) prosthesis socket serve to suspend (during swing-through) or maintain position of the device.

0020] All of these just-noted facts are important because they are reasons to vary the friction coefficient depending on the surface function. For instance, there is very little reason to be concerned about the friction coefficient of a surface in only very light contact with the skin (unless the number of repetitions is very high). Forceful cyclical contact against a skin surface is a situation that benefits more from minimizing the friction coefficient. If the area is "bony" minimizing friction becomes more important.

0021] In a case like the supra-condylar suspension areas of the BK socket mentioned earlier, high friction (even "sticky") materials may be desired. Applying the low friction patches of an aspect of the invention to certain areas and not others is a way to add friction management to the orthotist's (prosthetist's, podiatrist's, etc.) ...

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 pe...

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