Cushion Function
One of the most important factors relating to any cushioning product is understanding how it works. What added function does one product have compared to another and how does this relate to the proposed user?
There are a few basic principles that are used during the design of a product and one or more of these principles will be found in every cushion. Sumed provide three cushion types to achieve the same end ie protection for the individual, against unwanted and unnecessary seating problems.
The Principles
- Envelopment
- Added function
Following will be found descriptions relating to the use of different designs to address the same challenges. Choice is an essential part of user satisfaction and it should be remembered that regardless of whether a product works correctly for an individual, if it isn't liked, it isn't working.
The Nest Range
Envelopment
The Nest range of cushions approaches the basic principles in a different fashion. Envelopment is catered for by using foam of different thicknesses depending on the user's needs. This function is enhanced by using a contoured ADS base. This helps to redistribute the load over the maximum area possible, which leads to a reduction in tissue stress. An added benefit is that the ABS base helps to eliminate the wheelchair canvas sling effect resulting in a lower transfer height. The anatomical shape of the base with its integral pommel also helps to promote a stable neutral sitting position with natural leg separation. The contoured base also helps to eliminate sacral sitting.
Added Function
The foam pad has on its top surface an Akton® viscoelastic polymer pad. This provides an important added function to the performance of the product. Akton® like a fluid, giving uniform support, yet Is actually a soft solid, which will not bottom out. When pressure is applied at an angle to the skin surface, the various layers move over each other causing tissue distortion. This is called shear and different areas of the skin have different tolerances to shear forces. Deformation due to shear occurs where there is friction between the skin and the surface with which it is in contact, eg clothes. The frictional force will hold the upper layers of the skin stationary while the deeper layers move across one another. The Akton® pad acts like a second skin and provides a reduction in shear across the seating area. Akton® quickly adjusts to the shape of the body, however it will return to and permanently hold its original shape when not under load.
