Almost all office chairs have a height and arm adjustment; however, these are not the most important adjustments to look for when shopping for an office chair. The best office chairs have at least five adjustments with some having up to 14 different adjustments.

Important features that should be adjustable include lumbar support, arm width and height, seat back width and height, seat and back angle, and tension control. Many of the supports are dial controlled while a few are controlled with a hand-held bulb pump, similar to a blood pressure cuff pump.

Picking the right chair for desk can often be an afterthought, but it is advisable to take a little time to ensure you make the right choice, as you can easily end up spending a lot of time on it.

Lumbar support
Lower back support in ergonomic office chairs is very important. The lumbar spine has an inward curve, and sitting for long periods without support for this curve tends to 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.

Backrest
The backrest of an ergonomic office chair should be 12 to 19 inches wide. If the backrest 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.

Position and height
The position of your body changes throughout the day, and your office chair should make this change easy. Adjusting the tension controls for your body weight and changing the angle of the seat will put some of the upper body weight on the backrest. Swivel office chairs will ease tension caused by twisting at your workstation or desk. Ideally, you want your keyboard at elbow height, feet flat on the floor and your upper calves about 4 inches from the seat cushion.

Armrests
Fixed armrests are fine for occasional use, but for extended use, adjustable armrests are better. Adjustable armrests not only help to reduce the strain on your wrists and shoulders, they also reduce the tendency to slouch into your chair. They can also be lowered so you can pull your chair closer to your desk and still stay sitting in a comfortable position. Padded armrests could help you avoid putting uncomfortable pressure on the undersides of your forearms and elbows.

Headrests
A headrest can be particularly helpful for people who need extra neck or head support, such as those with back problems. They allow the muscles to relax and increase the blood flow. A headrest is usually only used when the chair is slightly reclined.