Did you know that the cushion you use as a primary aid to ease pressure and help regulate posture on your wheelchair has an interesting history? Before we get to the interesting story on memory foam cushions, let us first look at what memory foam is.
What Is Memory Foam?
Memory foam is primarily made of polyurethane an organic polymer, together with other chemicals to increase density and viscosity. Therefore, it is often referred to as viscoelastic foam. The viscoelastic nature of memory foam comes from several effects primarily because of their internal structure.
Just like every other sort of foam or sponge, memory foam tends to want to keep its original structure when deformed. This effect is caused by the deformed porous material which pushes outwards and wants to restore its structure.
However, memory foam is different. It has three opposite effects which work against this nature to restore its original structure. When combined, these three effects work to slow the regeneration of the original structure of the foam, which is perfect for forming memory foam cushions.
Another useful application of the material is that when memory foam is higher in density, it softens in reaction to body heat, which allows it to mold to a warm body in a couple of minutes. This foam is also breathable, with newer versions of the memory foam containing phase-change gel, which produces temperature stabilization or a cooling effect.
How Was It Invented?
Charles Host, an aeronautical engineer, helped in building a recovery system for Apollo in 1962. Because of his work on the Apollo, NASA decided to employ him four years later. He had to assist in improving airline seating in protection against crashes and vibrations.
He therefore created an open-cell memory foam material with great viscoelastic properties. NASA used this material and fitted it into their new airplane seat design. It not only offered better impact protection, but it also improved passenger comfort, because of an even distribution of pressure and body weight over the whole seating area.
NASA released this technology into the public domain in the early 80’s, but even before that time it was already in use in medical equipment such as X-ray table pads and in football helmet liners. Since then, it advanced more and eventually became cheaper to manufacture, and thus the widespread use. It is found in mattresses, shoes, blankets, pillows, and many other applications.
Most importantly, it is used as wheelchair memory foam cushions, hospital bed pillows and in padding for people suffering from long term pain or need postural support.
Why Is It Good For Us?
If you know what a pressure sore is, then you know that it is localized damage to the skin and the tissues that are underneath that area, usually under a bony prominence. They usually form because of pressure to the soft tissue or sometimes in combination with friction.
They usually affect people who are on chronic bedrest or who sit in a chair for long periods of time. Memory foam cushions reduce pressure on the skin by spreading weight over a bigger surface area. They also minimize friction forces. Since they are breathable, they also reduce sweat or the build-up of moisture.