It is often assumed that sitting is a relaxed position for the body; however, sitting for long stretches of time actually puts enormous stress on your shoulders and back. The key to relaxing your body while sitting is to maintain good posture. The chair in which you sit has the single greatest impact on your posture and, eventually, your productivity.

Here are some helpful tips in choosing a desk chair that provides good sitting posture and minimizes discomfort:

First, consider the place where you sit, also known as the seat pan. When sitting in a chair, you should have plenty of room for your hips and a few inches to spare. Your weight ought to be evenly distributed across the pan to eliminate pressure points, and the chair should still be comfortable after one to two hours of sitting. Make sure that the seat isn't too deep for your upper legs and that it is properly sloped so it does not catch you behind the knees.

Secondly, look at the height of the chair. Any chair you will be sitting in for more than a few minutes must have an adjustable height. You will get the best height position if you can change the chair height while seated. For good posture, you chair height should allow both of your feet to rest firmly on the ground.

Thirdly, evaluate the backrest. It is imperative that an office chair have proper lumbar support. The chair is more flexible if the lower back support can be adjusted. But if it is not adjustable, make sure it properly fits the contours of your body. It is also helpful to have a chair that will easily recline for different positions; it is hard on your body to be in a single position for an entire day.

Lastly, determine if you need armrests. For computer users, it is important to support your arms and hands, without adding strain to your wrists. The more flexibility you have in the armrests, the better posture you can achieve. The height of the armrests should definitely be adjustable. When set correctly, your bent elbows should rest on them while your arms are in a relaxed position at your sides. It can also be helpful, but is not necessary, to be able to move them entirely out of the way. Occasionally typing without the armrests can decrease the pressure on the ulnar nerve in your elbow.