Influence of different materials in multicomponent bandages on pressure and stiffness of the final bandage.

BACKGROUND The physical characteristics of bandage kits, in which different materials are combined, cannot be predicted by laboratory tests. They can only be assessed in vivo by measuring the interface pressure and calculation of stiffness. OBJECTIVE The objective was to investigate pressure and stiffness of some widely used multicomponent, multilayer bandages and to investigate the effect of modifications of their components. METHODS AND MATERIALS Twelve healthy volunteers were investigated. Interface pressure and stiffness were measured in the lying and standing position after application of four-layer elastic bandage (Profore, Smith & Nephew, Hull, UK), two-layer elastic bandage (Proguide, Smith & Nephew), and four-layer short-stretch bandage (Rosidal sys, Lohmann & Rauscher GmbH, Neuwied, Germany) applied according to the manufacturer's recommendations and after some modifications of the padding layer. RESULTS Both Profore, made up of elastic, and Rosidal sys, made up of inelastic components, fulfill the criteria for bandages with high stiffness. The stiffness of Proguide, consisting of elastic components, is in a gray zone between elastic and inelastic materials. Altering the padding layers changes the stiffness of these bandages completely. CONCLUSION Pressure and stiffness of composite bandage kits differ from the physical properties of their components. Modifying the padding layers leads to a change of these physical properties that can only be assessed by in vivo tests on the human leg.