Most companies take care to provide their staff with good seating that complies with health and safety standards. But what about the self-employed or office seating in the home?
Choosing a good chair
Firstly, make sure that the chair is appropriate for your working environment and the tasks you carry out. For instance, a meeting room chair is not designed to work well at a computer desk.
The secret to a good chair is adjustability. We all have different-sized legs, arms and spines, so try to find a chair which can be adjusted to support you in a good sitting posture. Your spine should be in an S-shape with your lower back supported in an arched position. It can be difficult to maintain good posture, so it's all the more important that the chair does the work of keeping you in a good posture.
Tips for choosing a computer workstation chair:
• Make sure the chair has a five base support and swivels through 360 degrees. This is important to give you freedom of movement and to allow you to get in and out of the chair easily.
• The seat-pan height must be adjustable to allow you to sit at the correct height.
• The seat-pan depth should be a few centimetres short of your thigh length, thus supporting most of your thigh but not compressing the back of your knee. This means that you can sit right back on your seat and get the full support of the backrest.
• The backrest should offer good lumbar support. It may need to be height-adjustable in order to fit you correctly i.e. the bulge of the backrest should fit into the small of your back.
• The backrest/seat-pan angle should be adjustable, preferably independent of one another, so that you can find a comfortable position
• Ensure the glides/castors are appropriate for the floor on which the chair is used – you should be able to move the chair around easily whilst still seated but you shouldn’t slide around either.
• Armrests should not obstruct access to the desk. This causes you to reach to use your input devices which in turn causes a poor spinal posture.
• The seat-pan should distribute your pressure evenly. If the seat-pan is cushioned, you shouldn’t make direct contact with the hard seat base.
• The chair should feel sturdy and robust.
If you're unsure about the suitability of a chair get the advice of an ergonomist or physiotherapist or contact your Occupational Health, Safety or Personnel department for help.
The sitting demands of someone with a bad back or a disability are very different to those of someone who has no physical difficulties. If you fall into this category get advice.
Adjust your chair
It’s all very well to have a chair that can be adjusted- but not if the adjustments aren't used! Familiarise yourself with the adjustments on your chair: you will probably need to experiment a little to find a position that is comfortable. Once you've found it there is no need to feel that the settings should remain fixed in that position. Your postural needs change throughout the day. You might want to recline the seat more while reading documents or interacting with other people, and then sit more forward when using your PC. At all times aim for an s-shaped spine, with a well supported lower back.
Change your posture frequently
So, you have a good chair and you use the adjustments properly. Unfortunately that's still not enough. The reality is that the human body is just not designed to keep still for prolonged periods of time, regardless of how good your postural support is. Breaking your sitting posture is essential to prevent the onset of fatigue and discomfort.
Taking a complete break away from the desk is ideal. However, not all breaks need be this disruptive to your work. Mini breaks are a very useful way of changing your posture. These can take the form of moving while remaining sitting to change your posture, e.g.: rolling your pelvis back and forward.
Most people see the sense in frequent breaking but find it difficult to remember to do so. A good way of overcoming this problem is to incorporate breaks into the normal routine of your job. Offer to get the morning and afternoon drinks for your colleagues, for example, or move your printer further away so you have to get up from your desk. Another way of designing in postural breaks is to alter the tasks that you carry out at work. The message is really: be a fidget at work! Some people set programmes or reminders on their PCs to remind them to break and there are special software packages to help with breaking.
Make sure that the other furniture and equipment you're using is appropriate and well arranged
The benefit of using a good chair can be undone by having to twist to see a poorly positioned PC screen. Make sure your chair fits under your desk. Don't perch on the edge of your chair to reach forward to your desk and ensure your feet are well supported.
How to Adjust your Office Chair
Your chair should be comfortable whilst supporting your spine in an s-shaped posture. A good office chair will offer you adjustability and adequate support of your lumbar arch (the “small” of your back). Most chairs have instructions on how to adjust them attached (they are sometimes well hidden so look underneath) or you can find the instructions on the internet.
Take the time to familiarise yourself with your chair’s adjustments, then follow these easy steps to set up your chair:
- Raise the seat-pan height so that your elbows are just above desk height when you are sitting with your arms by your side. When you place your fingers on the home keys of your keyboard, your forearms should be about horizontal.
- Adjust the depth of the seat-pan. Your back should be in contact with the backrest and there should be about an inch or more between the front of the seat and the back of your lower legs.
- Adjust the backrest height so that the backrest bulge fits into your lumbar arch.
- Adjust the tilt of the backrest so that it is comfortable; this is usually a few degrees into a reclined position.
- If you have an unlocked synchro or free-float chair, set the backrest tension (resistance) to suit your weight. The backrest should not feel like it is pushing you forward nor should it collapse backwards when you lean back against it.
- Adjust your armrests so that they don’t prevent access to the desk. They shouldn’t cause your shoulders to hunch up.
- You will need a footrest if your feet are not well supported on the floor.
Remember to pull your chair well into the desk so that you do not have to reach for your input devices.