Years ago when working on an automobile engine I noticed that I would unconsciously lean over the engine for up to an hour at a time. When I went to straighten up the pain was intense. The result of this was that I eventually learned to force myself to stand upright and stretch a bit every 15 or 20 minutes. Unfortunately when we are working at an office environment sitting in an office chair we may not have the opportunity every half hour to go on walkabout.
With this in mind office chairs must be designed so that the back and other parts of the body are properly supported. An office chair without proper lumbar support results in the body being slumped over much like mine was when working on the car. Other important choices to be made when purchasing office chairs are the use of fabric, leather or vinyl as a seat material and the amount of seat and back adjustment available in that chair.