Where to find a good and cheap ergonomic chair?

An ergonomic work chair is a famous catchy name of a good if not the best kind of office chair. But what does exactly stand behind the best ergonomic computer chair?

A popular dictionary defines something ergonomic as a product designed to minimize physical effort and discomfort and in this way maximize efficiency of your working process. In other words, in ergonomics office chair I designed to keep a person extremely comfortable so he can fully concentrate on his job. There are a few parameters that help a simple cheap chair to be an affordable ergonomic chair.
First of all, an important factor is height of a chair. The best chair should have both seat and arms rests adjustable to have a perfect natural posture that will feel comfortable. Some really good chairs also have adjustable back rests.

Another factors of an inexpensive ergonomic chair is sizing and back support. Seat width and depth as well as back rest width are very important and must fit your body well. A bigger or a smaller seat, for example, won’t give enough support to the person’s back and the rest of the body.