Experimental Investigation of Subcutaneous Pressure and Shear Force Changes Using a Bone Protrusion Model as a Risk Factor for Pressure Ulcer Development

Abstract

Objectives: Subcutaneous pressure and subcutaneous shear force were investigated using a bone protrusion model to investigate a polyurethane film dressing (hereinafter referred to as adhesive film) for preventing shear force. Our hypothesis was that when pressure or shear force was applied to the body surface, the adhesive film would 1) decrease the shear force on the skin surface and 2) decrease the effect of the external force on the subcutaneous layer.

Methods: We built a bone protrusion model using pig skin equipped with a plastic stand and sensors that can simultaneously measure subcutaneous pressure and shear force. In this experimental model, changes in shear force and pressure were measured using a surface friction-measuring device and a subcutaneous sensor.

Results: In the bone protrusion model, the effect of body weight on the surface shear force was significant. Contrarily, in the subcutaneous fat model, the effect of the body weight on the subcutaneous shear force was particularly small. When the adhesive film was applied, the surface friction, subcutaneous pressure, and subcutaneous shear force all significantly decreased.

Conclusions: A bone protrusion model was created, and the surface friction, subcutaneous pressure, and subcutaneous shear force were continuously measured and found to decrease. The pressure and shear force were reduced when the adhesive film was used. These results will be of great help in the treatment of bedsores.