The following are the top important things to consider when selecting an office chair:
All office chairs should have a pneumatic mechanism to easily lower or raise your seat pan. You should be able to adjust the height so that the front of your knees are level to the ground, and your feet are firmly on the ground
Chairs should have a cushioned lumbar support to help stabilize your low back
Seat Pan Shape
As you sit in your office chair, the seat pan should be at least one inch wider than your thighs and hips on each side. It should be contoured for even weight distribution. It should also have a waterfall-like contour at the front, for comfort on your thighs
Your chair should have sufficient depth so that you can sit all the way back in the chair. If the seat is too shallow, you will sit too far forward putting undue pressure on your thighs.
Test Your Chair Long-Term
When trying out office chairs, test them for longer than 1 minute in the store. You will be using these chairs for literally days, and comfort can change after a period of time
No matter what brand of chair or its features, if a chair (or any product) is not comfortable, seek an alternative. Studies show your level of discomfort and fatigue using office chairs is directly related to low back and neck pain. The more comfortable the product, the less pain!