Man and machine in perfect harmony?
Many of us sit in front of PCs for hours on end - in many cases for much of the working day - and often don't consider the potential impact on our health. So what are the risks of prolonged PC usage - and what can be done to minimise these?
26 July 2005
The question of getting your workstation ergonomics right - and your working practices - isn't a trivial one. Incorrect posture can lead to non-trivial injuries, such as repetitive strain injury (RSI) and back problems such as a slipped disc. Such injuries can be very hard to correct and can severely reduce the quality of a person's life. Eyesight problems are also an issue - our eyes weren't designed to stare at one focal point all day long, nor were they designed to handle images that constantly flicker. And again, degradation of eyesight can be a one-way street.
So what can be done?
Seating
We're not a sitting animal - we're a standing animal. Our bodies don't take kindly to slouching postures. Although we may not realise this, incorrect or lazy postures put a lot of stain on a back.
So, getting your workplace chair right is very important. A chair should be height-adjustable, tilt-adjustable and the back position should be adjustable too, providing firm support to the lower back. A good sitting position should be to sit up straight, with your knees level with your hips. A chair should hold you comfortably in this position.
Your feet should be flat on the floor, otherwise you're too high up. However, your height may be dictated by the height of your desk, so adding a footstool can compensate for this. Your legs should not be crossed, nor should you sit with one of your legs (or indeed both of them) twisted beneath you.
It's easy to slip into a bad posture, so you need to be mentally checking yourself throughout the day and correcting your posture until it becomes habit. Interestingly, many back experts also recommend that, if possible, you vary your working position. There are some (expensive) desks available which can be raised electronically to enable you to work standing up for part of the day. Although this seems to be an odd idea, it's actually quite natural in practice - indeed, Winston Churchill used to do this.
Your monitor
It's important to position a monitor correctly. The ideal distance from the eye is between twelve and thirty inches. For most people, this is approximately an arm's length away. The top of the screen should be roughly at eye level (although for those with larger monitors, the eye often more comfortably lines up with the top half of the screen).
Glare on the monitor should be avoided - and this usually means making sure that direct sunlight isn't cast onto the monitor. Having a monitor at right-angles to a window is about right, but if you can't manage this, blinds can help direct light away from a screen, and, in some circumstances, an anti-glare screen can help. The monitor refresh rate should be checked - if this is too slow, it can cause a visible flicker which is very uncomfortable in prolonged use. To check this, right-click on your desktop and select 'properties'. Then select the 'settings' tab. Then select 'advanced' and then select the 'monitor' tab.
If you are using a CRT monitor (not a flat panel) then the screen refresh rate should be 80 Hertz or above. However, don't change this unless you are sure that the monitor can handle a higher refresh rate - check with your IT department before doing it. LCD monitors don't need such a high refresh rate to hold a rock-steady image, especially if they use a DVI digital connection. An LCD monitor is preferred - indeed, Boots Opticians recommends their use above CRTs.
Keyboard and mouse
Your wrists should be straight when using a keyboard and the mouse should be within easy reaching distance - as close as possible, so you don't have to stretch for it. A mouse mat with a wrist pad will help to keep your wrist straight, holding it in the correct position and relieving strain on the arm.
Laptops
Laptops are more and more popular computing devices. However, their design is fundamentally different from desktop PCs, as are the ergonomics. In fact, the ergonomics of laptops violate the basic requirements of a computer user - to separate the keyboard and screen. This has resulted in a significant increase in musculoskeletal problems.
Typically, a laptop monitor is at lower than the ideal height, people tend to sit closer to the screen than is ideal, the keyboard is close to the monitor than is ideal (and often can't be changed) and this engenders very poor posture - almost hunching over the laptop with an arched back. Using a laptop in this way is OK for short periods, but if you're working on one all day long, you should consider one or more of the following.
An external monitor enables you to separate the keyboard from the monitor and get the screen at the right height. A less expensive alternative is an external keyboard and mouse, which then allows you to raise the laptop up on a stand. For those who carry a laptop around a lot, it obviously makes sense to get the lightest device possible - larger laptops create real strain on the neck and can cause injury.
Take a break
This is the hardest one, but important for several reasons. It's important for your eyes that they don't stare at the same distance all day and important for your back that you don't sit in the same position. For every hour worked, you should take a five- or ten-minute break. For many, this happens naturally, as meetings and the like break up the day - but otherwise make sure that you do this. When you do, try to focus on something in the distance rather than close by.
The telephone
If you spend a lot of time on the telephone, a headset can be a terrific boon. The common practice of cradling the standard headset between the head and shoulder creates a lot of strain on the neck - which a headset totally alleviates. This is especially useful for those who need to use their PC while they are on the telephone.
So, while we might be tied to our PCs, there's a lot that we can do to minimise the risk to our health. Most of this is simple and inexpensive - and while it's easy to put off making changes, you may well regret it if you don't.
Disclaimer
This article should not be treated as a substitute for the medical advice of your own doctor or any other health-care professional. e-academy is not liable for any actions undertaken based on the content of this Web site. Always consult your own GP if you're concerned about your health.
