The selection of a suitable chair is a critical step in preventing health problems in people who work in a sitting position. With the ergonomics approach, sitting is viewed as a specific, specialized activity which is influenced by the way that a sitting person interacts with the working environment.

Several basic concepts should be considered:

• One chair does not fit everyone. The users' body dimensions must be used when selecting a chair so that it does not strain one part of the body while fitting another.
• Collect data about the user's body height. The optimal seat height is about one quarter of the body height. This is only a rule of thumb since the torso-to-leg ratio can vary widely..
• No one chair is suitable for every activity. For example, dentists require a different chair than do industrial workers or computer operators
• Consider maintenance and repair costs. Check with the manufacturer for items to inspect for and how often inspection should be done.