Do you mean the comfort chairs?
http://www.hslchairs.com/advice/comfort-chairs/
par of my job used to be helping people with disabilities to find a suitable chair so I know a bit about it....The best that anybody can do when assessing and suggesting chair size and shape is to suggest one that is the most anatomically correct in terms of chair height, width, lumbar curve seat depth and so on. What NO ONE can guarantee is that the user will find the chair comfortable no matter how much care is taken with measurement and assessment.
Make of that what you will :)