Office chairs are essential to have around an office, yet they offer so many features. For people of all sizes, adjusting an office chair is something we all should know.

You should adjust the height of the chair so that your feet are able to rest comfortably on the floor, with your thighs horizontal. If your feet cannot rest on the floor, you'll need a footrest.

If your office chair has a pneumatic level, height adjustment can be accomplished from a seated position. In order to raise or lower the height of older office chairs, you'll need to stand in front and rotate the seat clockwise or counter clockwise. You'll know the height is right when the height of the seat pan is just below the height of your knee caps.

You should always avoid situations where your feet dangle, as this will compress the tissue on the back of your thighs and behind your knees, also leading to aches and discomfort in the lower legs. There should be a space about the width of a clenched fist between the back of the knees and front of the chair.

If there isn't, lower the chair slightly. If the chair has the ability, tilt the seat pan forward to slightly relieve the pressure. You may need a foot rest. The rounded edge on many office chairs will also help to prevent uncomfortable pressure behind the knees.

At your desk, your office chair should be adjusted to accomodate the working surface. What this means, is that your chair should be raised high enough to keep your sitting comfortably at your desk.

Adjusting the backrest You should adjust the backrest so that it supports the lumbar area of your lower back. As this is the most important contact point, taking care of your lower back is very important.

In most situations, and especially where your job requires you to sit in your chair for an extended period of time, your backrest will need to have an adjustable height so that you can get the maximum amount of support for your back. There are some backrests that can even be moved forward or backwards.

If the seat pan is deep, these features can be even more useful. Whatever you do, never sit in a chair for a long period of time without back support. You should adjust the chair instead, as this will protect your back while you work.