Effects of Humidity on Skin Friction against Medical Textiles as Related to Prevention of Superficial Pressure Injuries

Frictional forces and humidity are pivotal physical factors in the development of superficial pressure injuries (PIs). To date, further research is needed in order to understand the influence of humidity on skin coefficient of friction (COF) against different types of medical textiles such as support surfaces, covers and dressing materials. In this work we investigated the effects of humidity caused by urine, sweat and saline (as a substitute for the fluidic environment of wounds), on the COF of porcine skin against medical textiles, in the context of pressure injury prevention. For that purpose, we used a tilting-table tribometer, together with finite element (FE) computational modeling. The COF obtained for porcine skin against the fabrics that were tested varied between 0.59 (adult diaper) and 0.91 (polyurethane foam). Furthermore, the COF increased with the added humidity in all of the tested cases. In closure, moisture can, in fact, accelerate and promote the formation of superficial pressure injuries, due to the increased COF between the skin and fabrics in wet conditions, regardless of the type of liquid. Hence, reduction and clearance of moisture between skin and adjacent medical textiles is a key measure in superficial PI prevention.