It is recommended for the user to try out the chair for comfort and fit over an extended period of time prior to purchase. The following criteria may not accommodate all individual body types.
1. The chair should be easily adjustable.
2. The chair should have a sturdy five-legged base with proper chair casters that roll easily over the floor or carpet.
3. The chair should swivel 360 degrees so it is easier to access items around your workstation without twisting.
4. Seat height should adjust from 15 to 22 inches.
5. Seat pan length should be 15 inches to 17 inches.
6. Seat pan width should be at least as wide as the user's thighs. A minimum width of about 18 inches is recommended.
7. Seat pan tilt should have a minimum adjustable range of about 5 degrees forward and backward.
8. Front edge of the seat pan should be rounded in a waterfall fashion.
9. Material for the seat pan and back should be firm, breathable, and resilient.
10. The seat pan depth should be adjustable. Some chairs have seat pans that slide forward and backward and have a fixed back. On others the seat pan position is fixed and the backrest moves horizontally forward and backward so the effective depth of the seat pan can be adjusted. Beware of chairs where the back only tilts forward and backward. These may not provide adequate adjustment for many users.
11. The backrest should be adjustable and should provide lumbar support that matches the curve of the lower back. The top of the backrest should be at least 17.7 inches above the compressed seat pan and 14.2 inches width (ANSI).
12. The backrest should allow a recline of at least 15 degrees and should lock into place for firm support.
13. If the backrest reclines more than about 30 degrees from vertical, a headrest should be provided.
14. Armrests should be removable and the distance between them should be adjustable. They should be at least 16 inches apart.
15. Armrest height should be adjustable between 7 inches and 10.5 inches from the seat pan. Fixed height armrests are not desirable, especially for chairs that have more than one user.
16. Armrests should be large enough (in length and width) to support the forearms without interfering with the work surface.
17. Armrests should be padded.
18. Most chairs are designed for weights under 275 pounds. If the user weighs more than 275 pounds, the chair must be designed to support the extra weight.