Office chairs are ordinary enough. Everyone knows what one looks like. Many of us have sat in one and many of us have one. There are various types, sizes, colours and shapes. However, the one that most promptly springs to mind is the one that most people would call the executive office chair. These are usually black leather executive reclining chairs.

These executive black leather reclining chairs look very comfortable and high status. The best ones also have various adjustable devices on them. However, in spite of the familiarity of these chairs, how many people know how to utilize these adjustments to their full advantage? I will run through the different best settings in the next few paragraphs.

The most important feature to get correct is the height of the seat off the floor. This depends on the length of your calves and the height of the desk. The desk should be roughly the same height as your elbows and your feet must be able to rest flat on the floor. If they cannot do that, then you will need a foot rest, otherwise you do not. The thighs will be more or less parallel to the floor

The height should be variable from the sitting position, so that you can get it right without difficulty. People tend to give up when it is 'about right', if they have to keep getting up to fiddle with the chair. Older chairs are sat on a spindle and they are wound up and down by turning the seat to the left or the right. Modern chairs have a lever to alter the height pneumatically or hydraulically.

The worst scenario is to have your feet unsupported, because this puts the full weight of your legs on the back of your thighs. This will cause the veins there to compress against the seat pan, which will reduce the blood flow, causing cramp and pain. This can be caused also if there is insufficient space between the edge of the seat and the back of your knees.

If this ideal position cannot be achieved by the changes noted above, you can compensate by allowing the chair to dip forward a little until your feet are flat on the floor. You may have to drop the seat a little in order to accomplish this. We all naturally assume that office chairs recline so that the boss can lay back and put his feet on the table, but they 'recline' forward too so that you can get your posture correct.

The back rest must support your back and there ought be a lumber support as well. The lumber support may be adjustable upwards and downwards and can also be inflatable. Make sure that it fits comfortably into the small of your back. Some chairs have electrically operated massage units built into this lumber support and they are fantastic.

Adjust the back rest forward or backward to be comfortable, do not just put up with the existing settings. Likewise, adjust the head rest upwards or downwards so that you can rest your head on it when you lean back.

If there are arm rests, they should be broad enough for your arm and be set at the right height. They should come up to your elbows, so that you do not have to slump into your chair to use them.

If you use the settings on your office chair properly to suit your body size, you will find that you will not get so tired so quickly, but you should get up and move around for a few minutes every hour as well in order to keep your circulation good.