Type of activity Polyvalent activities: taking notes, making phone calls, meetings, computer work. The chair should allow a large variety of movement, therewith a constant maintenance of the back. Office activities: working at the desk more than 50% of your time. To sit in the chair long amount of time is very exhausting for your back. The desk chair must permit sitting in a correct position like respecting the natural curve of the spine. User type Every one is unique: tall or short, tight or thin. The desk chairs must have the possibility to be personalized through operative and easy adjustements. By waist: in sitting position, the back side of the chair must be able to be adjustable in elevation, without any distorsion, for placing lumbar area sustained. By weight: the pressure and bent of the back side of the chair must be effective. Such as, the user, must be able to move his chair without any surplus effort, remaining in, the same time, well sustained. Qualitative criterion Foam rubber comfort: a high density foam rubber has more durability in time than an usual one. A durable comfort must be ensured. The resistance and solidity of all our chairs have been tested in order to establish the guaranty term from 1 to 5 years.