Development of a simple approach to modify the supporting properties of seating foam for pressure relief

Pressure sores are a major problem frequently encountered by persons who use wheelchairs. Custom seat design, including contoured seating and various modular seating devices, has become an important option for pressure relief, especially when the market size is small and the variations of individual needs and requirements are large. An alternative approach in custom seating design for pressure relief is proposed in this paper. Holes were drilled in foam cushions to lower their supporting properties, particularly at the high pressure areas. This technique is evaluated systematically in this article. The scope of this study included: 1) a comparison of the foam material properties before and after such modifications, and 2) an evaluation of the static and dynamic degradation behaviors of the foams before and after modifications. It was found that the compression load (C-L) of the foam could be reduced by up to 46% using this simple drilling technique, while the material removed was only up to 28% by volume. It was also found that this approach would not significantly compromise the static and dynamic degradation behaviors of the foam; that is, such modification apparently did not dramatically shorten the lifespan of the foam material. Simple hole-drilling seems to be an effective approach to altering the supportive properties of foam cushions for pressure relief.