Ergonomic chairs have a lot of controls and a huge range of settings. Ensure you get the most out of your investment by understanding what the controls do, and how to set them correctly. Not all chairs are the same, and won’t necessarily all have the features listed here.
First have a good look around and under your chair. Some controls are well hidden. Play with them all and understand what they do.
Various types of castors are available, and the wrong ones can cause problems. Soft castors are preferred for hard floors, and harder castors for soft floors. They can be ‘braked’ when loaded so the chair can not moved when sat in, but then getting it to the right position can be a problem. Other locking mechanisms are available, but are unlikely to found on a standard chair.
The base of a wheeled chair should have 5 legs, and the higher the chair is able to go, and the heavier the user, the wider the base will need to be. A good chair will be guaranteed to work for most people up to around 150kg.
The height of the chair should be adjusted so that when the seat is level, the feet are flat on the floor and the thighs are level with the ground. Ideally, the height of the desk should be altered so that the armrests (when themselves correctly adjusted – see below) meet the work top.
Shorter people may need a footrest to keep their feet planted, taller people may need to raise their equipment, ideally the entire desk.
Seat depth is crucial, and the lack of adjustment on cheaper chairs is possibly the biggest cause of back pain in ill fitting chairs.
With your backside firmly in the back of the seat, knees together and feet flat on the floor, adjust the depth of the seat so that there is a gap of between two and four fingers, between the front of the seat and the back of your knee. You may have to stand up to slide the seat.
If there is no gap, and no seat slide on the chair, it is not suitable for you. You could put a back support or cushion behind you, but you should not consider this a long term solution, any more than you would stuffing newspaper into large shoes to make them ‘fit’.
Too much gap isn’t so much of a problem, but if you can get more than a whole flat hand in the space, again, you need to look to finding a correctly fitting seat that better supports your legs.
Some chairs come with an adjustable lumbar support of some sort. Many use an air cell, pumped up with a small hand pump, some have a pad or cushion of some sort that is adjusted forward and back. Chairs with a mesh back may have a pad that slides up and down.
Everyone likes a different level of lumbar pressure, it’s a personal preference. Many people adjust the pressure through the day.
Some lumbar supports can be adjusted independently of the backrest, on others the entire backrest and lumbar will be height adjustable. Some will have height adjustment and no lumbar.
If you first pump up the lumbar so you can easily feel it’s presence, you can then adjust the height of the backrest or lumbar so that it is comfortable for you.
A neck or headrest is often an optional extra. It can enhance comfort and for some tasks improve support. It may be more useful for those with existing neck or shoulder issues.
Adjust it so that it is not intrusive. Most are designed to fit into the nape of the neck, but it should not be applying any pressure, or even touching you during normal screen work. If your relaxing back, watching video or talking on the phone for example, position the support so that it is comfortable.
An area of extreme importance that is often overlooked is armrests. Poor adjustment, or lack of available adjustment can contribute to upper limb disorders: shoulder and neck pain. Do spend a couple of minutes getting them correct.
The amount of adjustment available on armrests varies as much as the entire chair. If the chairs seat is particularly wide, it might not be possible to bring the top of the armrest in close enough to the body.
Adjust the width of the arm rest so that your elbows rest comfortably on them without having to reach out. Some are adjusted at the base of the arm, where it enters the chair, on others the top pads slide independantly of the arms. Your elbows should remain under your shoulders.
With your hands resting in your lap bring each armrest up so that they rest just onto your elbow. It’s important not to raise them too high.
Often there will be adjustment forward and back, usually just the top pad. When typing push the pads forward, not so far that they get in the way of the desk, but so that with your elbows rested on them, your wrists can comfortably reach and rest in front of your keyboard.
Some have turnable tops. When typing, turn the tops inwards to reduce lateral movement of the wrists.
Some armrests angle forward or back from the chair to the pad, and can be fitted either way. They should never impede access to the desk, so for slimmer people, the armrest will need to be fitted so that they angle back. Larger people may need them fitted so that they angle forward in order to benefit from them.
Now you have the chair correctly set for you, bring it to the desk. Ideally, you’ll have a height adjustable desk, and position it so that the table top is level with the armrests.
Most will not have this luxury. Shorter people will need to raise the chair, and use a foot rest. Taller people should avoid roudning the shoulders and bending their neck. Ensure screen are placed so that the top of the viewing area is at eye level. Desks raisers placed under the feet of the desk are a cheap an effective way of raising the enitre workstation.