Glossary

• Memory Foam

  Memory Foam was invented by NASA in 1966. The idea was to improve the safety of aircraft cushions, but it was not long before th material was developed further and used in more and more products. Memory Foam is an open cell construction, which reacts to body heat and weight. The more heat applied, the softer the material gets. This, in turn, allows the weight applied to sink deeper. Memory Foam can be made at various densities to result in different tensions/firmnesses.

  The crucial element of Memory Foam is that it softens and moulds to the body shape. This ability allows for very accurate contour support and weight distribution. This ability makes Memory Foam a desirable material for mattresses. Some mattresses are completely Memory Foam, perhaps using different layers of various densities. Some mattresses use Memory Foam to compliment a Spring Unit.

  As Memory Foam requires heat to achieve its desired state, the heat is stored. Some people are not keen on Memory Foam as this heat can gradually build, resulting in a warm bed. However, this stereotype can be seen as outdated, as many manufacturers have solved the issue by applying new techniques to compliment the Foam. Techniques such as Outlast and Coolmax. Memory Foam is also Hypoallergenic and is therefore very popular with Asthma and Allergy sufferers.

• Pocket Sprung

  Pocket Sprung units are an adaption of the traditional open coil/continuous spring unit. By placing each spring in its own individual 'pocket' (a fabric sock-like pouch), the spring is not joined to any other part of the mattress. The pocket that supports the spring is then joined to its neighbouring pockets and this effect creates a unique feel.
  
  By creating a spring unit in this way, it allows the springs to move independently, rather than sharing the pressure with surrounding springs. This effect allows for much more accurate contour following and a more comfortable feel overall.
  
  If you were to push your hand into a traditionally sprung mattress, the area around your hand would dip/sink too. With Pocket Springs, this sunken area is much more remote and therefore more accurately follows the contours of the pressure source. There are differences in the techniques used to create Pocket Springs, but more or less they remain the same.

• Pressure Points

  Pressure Points are created in the body when lying on a mattress which is not suitable for a persons physique. The Pressure Points are caused by putting stresses through the body. When the spine is not aligned correctly (i.e, straight), it can cause pressure to build up in the back, hips or shoulders (etc).
  
  When a bed is too soft, the body sinks in, causing certain areas to be under the strain of the rest of the body. When a mattress is too hard/firm, then the weight applied can cause the body to flex/bend in the opposite way - causing a similar problem. Hips, shoulders and so on, are requried to be sunken into the mattress slightly more than the surrounding areas, as they carry the weight. When this is not the case, the lower back may be bent to compensate. The ideal mattress is one which will keep the spine straight.

• Turn / No Turn

  Some mattresses require turning over, to aid even settlement. Others do not require turning, but will still require rotating.