Finding a Chair
The best way to find a good chair is to have it tested by the person who will be using it. To check for a proper fit, start by ensuring that the person's feet can rest firmly against the ground while the thighs remain level on the seat cushion. The chair should be rounded in front to avoid reducing circulation below the knee. The seat cushion, or seat pan, should feel comfortable, and the person's weight should feel evenly distributed throughout the seat. In addition, the back rest should feel comfortable; a contoured backrest will often provide greater lumbar support.
Also, check that a number of different seated positions can be accommodated comfortably. If the user often leans back, make sure that doing so does not result in any neck tension. To promote good posture when leaning forward, it can be helpful to have a chair that has a forward tilt, which will place the hips a few degrees higher than the knees. Finally, arm rests, if available, should be designed in a manner so the chair can be pulled up close to a computer keyboard or desk surface.
You should also consider the work environment in which the chair will be placed. There are different types of chair casters depending on the floor surface. While hard wheel casters are appropriate for a carpeted office, soft wheel casters are preferable for other floor materials to avoid damage.