|Lower back support is very important. Sitting for long periods without proper support can lead to slouching (which flattens the natural curve) and strains the structures in the lower spine. An ergonomic chair should have a lumbar adjustment (both height and depth) so each user can get the proper fit to support the inward curve of the lower back.
The backrest of an ergonomic office chair should be 12 to19 inches wide. If it is separate from the seat, it should be adjustable in height and angle. It should be able to support the natural curve of the spine, again with special attention paid to proper support of the lumbar region. If the office chair has the seat and backrest together as one piece, the backrest should be adjustable in forward and back angles, with a locking mechanism to secure it from going too far backward once the user has determined the appropriate angle.
The material on the seat and back of the ergonomic office chair should have enough padding to be comfortable to sit on for extended periods of time. Having a cloth fabric that breathes is preferable to a harder surface.
Armrests should also be adjustable. They should allow the user's arms to rest comfortably and shoulders to be relaxed. The elbows and lower arms should rest lightly, and the forearm should not be on the armrest while typing.