New methods for evaluating physical and thermal comfort properties of orthotic materials used in insoles for patients with diabetes

Abstract

Abstract-Orthotic insoles are commonly used in the treatment of the diabetic foot to prevent ulcerations. Choosing suitable insole material is vital for effective foot orthotic treatment. We examined seven types of orthotic materials. In consideration of the key requirements and end uses of orthotic insoles for the diabetic foot, including accommodation, cushioning, and control, we developed test methods for examining important physical properties, such as force reduction and compression properties, insole-skin friction, and shear properties, as well as thermal comfort properties of fabrication materials. A novel performance index that combines various material test results together was also proposed to quantify the overall performance of the insole materials. The investigation confirms that the insole-sock interface has a lower coefficient of friction and shearing stress than those of the insole-skin interface. It is also revealed that material brand and the corresponding density and cell volume, as well as thickness, are closely associated with the performance of moisture absorption and thermal comfort. On the basis of the proposed performance index, practitioners can better understand the properties and performance of various insole materials, thus prescribing suitable orthotic insoles for patients with diabetic foot.

Novel Insole Material for Weight-Bearing Monitoring Medical Device to Be Used in Fractured Bone Clinic

“…Polyurethane foam and high-density polyethylene foams with hardness Shore A 32-35 are among those with best shock absorption characteristics. In an attempt to simplify the process of identifying suitable materials for orthoses some authors developed models such as performance indexes (Faulí et al 2008;Lewis et al 1991;Lo et al 2014;Paton et al 2007), and analytical hierarchy model (Almomani et al 2016)). So far, none of these is without substantial limitations.…”

“…Besides other criteria the model accounts for choice of the most economical material for production, which for example is not considered as important in performance matrixes suggested by (Faulí et al 2008;Lewis et al 1991;Lo et al 2014;Paton et al 2007). However, since the input factors differ from previous studies with the use of performance indicator, it makes it challenging to compare with other studies.…”

“…suitable for use as adaptation or filling. With the endless combinations of each material available (material thickness, density and hardness) the actual practicality of the reported method is questionable Lo et al (2014). also applied performance matrix for determination of the best candidate for accommodation, cushioning and control categories.…”

Curvature control of weft-knitted spacer fabric through elastic inlay

“…Wearable cushioning products, such as orthopedic supports, prosthetic liners, knee and elbow protective paddings, sports bras and orthotic insoles are typically made of thermoplastic foams or polychloroprene rubber to absorb the impact forces. [1][2][3] The barrier materials, however, inhibit heat and moisture transport. A layer of knitted fabric as the cover to provide bidirectional stretch is therefore applied to enhance comfort and reduce skin abrasion.…”