Memory foam was developed by N.A.S.A during the 1970's. It was then realised that this foam had the potential for use in the medical industry to avoid and relieve pressure sores.
In its use for that purpose, it was then realised that due to the way the foam responded to temperature and also its ability to spread pressure over a greater surface area compared to conventional mattresses; the foam was ideal to give orthopaedic support to the entire body.
The ability to shape itself and support the body in this way is unique to memory foam.
Sprung mattresses and other foams compress when you lie on them but want to spring back to their original shape immediately. This acts as a force against the body.
However memory foam is an open cell foam. This means that the individual cells have holes in them which enable the foam to compress fully and spread air to the adjoining cells.
Memory foam supports the whole of the body completely and comfortably. When you lie on it, memory foam spreads the pressure much further throughout the mattress than conventional mattresses have the ability to do. It conforms completely to your body shape and relieves the pressure from weight bearing areas.