It’s a familiar sight: the computer user hunched over his keyboard, eyes inches from the screen, back curved in a C shape, legs crossed under the desk. His right hand is moving the mouse around but the rest of his body is frozen in one position.

It’s also a recipe for muscular skeletal injury; severe enough to affect his ability to do everyday tasks, such as making a cup of tea or dressing himself. Potentially, he could lose the use of the affected limb or limbs and there’s a chance his disability won’t be covered by ACC.

There are two forms of OOS. Type one includes conditions such as like epicondylitis (tennis elbow) and carpal tunnel syndrome. It involves a discrete injury site, is relatively easy to diagnose and is likely to be covered by ACC. With the second type it is harder to pinpoint the exact site of the injury. It may affect multiple parts of the body and may even move from one part to another. And because it’s hard to diagnose, it will not necessarily be covered by ACC.

There are a few simple steps you can take to help avoid computer-induced injury. The first is a workstation assessment.

ACC and Occupational Health & Safety both provide a list of companies that offer this service. In an assessment, an occupational therapist will look at the fit of your chair and workstation equipment, and ensure everything is set up to optimise comfort. An assessment costs around $80.

They may recommend replacing furniture or computer equipment. You need a desk that’s of the right height for your size (the average desk height is 720mm) and an adjustable chair that provides lumbar support. Your angle to the window is also important, as is your

Some companies are now training people on their staff in workstation assessment, and there’s a wealth of information on ACC’s Web site (see boxout), with diagrams and exercises for deskbound workers.

Ideal posture at the computer begins with maintaining the natural curve of the spine. Your head should be directly over your shoulders and your shoulders over your pelvis. Your chair should be at such a height that your feet are flat on the floor.

But that’s only part of the equation, according to occupational therapist Janelle Aitken from Ergo Design.

The way in which you work is also of vital importance: you need to take breaks and you need to change your position regularly, Aitken says. Try to avoid the “ready, steady, go” position, she advises, by which she means having your hand constantly resting on the mouse, and your fingers over the keyboard.

“If you’re thinking about what you’re doing or if you’re on the phone, try to use that as an opportunity to change your posture and get out of that keying mode. Rest your arms beside you or in your lap. Take your hands off the keyboard,” she says.

It’s not an easy habit to get into, especially for people used to concentrating on a task for long periods of time, but it actually increases productivity, rather than the reverse.

For people doing intensive, repetitive work such as data entry, in particular, micropauses are essential. That means resting your arms for a few seconds, every five minutes. There’s a certain type of person who’s more prone to developing OOS, Aitken says: “They seem to have an ability to concentrate for longer periods of time and they seem to have a stronger work ethic than most of us. They don’t cope as well with work stress as others do. They tend to keep going and going and going and they have the ability to switch off from pain and everything that’s going on around them and become very focused on what they’re doing.”

If you recognise yourself in that description, it’s time to make changes to the way you work.

Working with companies to promote healthy computer use, Aitken says she comes across people from all walks of life and all professions who are affected by OOS. It’s more prevalent, however, in contact centres, where workers are tethered to their workstations; people who get out of the office or away from their desk regularly are less prone such to injuries.

If you do start to feel discomfort or pain associated with computer use, the first thing you should do, advises Aitken, is get your workstation assessed.

If you’re suffering from ongoing pain that lasts outside of work, it’s time to see a doctor, who may prescribe a course of anti-inflammatories and possibly refer you to a physiotherapist.

Regular, low-intensity cardiovascular exercise is also important. Exercise promotes circulation to muscles that may be tense and tight from long periods at the computer – walking, running and swimming are all useful. It’s a good idea to get expert help on the right exercise for you if you do have an injury since the wrong type of exercise may make things worse.

It’s not just office workers who are at risk from muscular skeletal injury, either. There has been a lot more focus on ergonomics in schools recently, and many more children reporting discomfort. At home, too, children are often at computers for long periods of time, at desks that are too high for them, which results in them sitting with their shoulders raised and their arms in awkward positions. The height of the desk is as important as that of the chair, Aitken says.

There’s a lot of information available about what is a good, ergonomic chair and what isn’t, she says. It’s essential, when buying a chair, to try several out and see whether you’re getting the right level of lumbar support. If you can feel the back of the chair contacting your back, and it’s comfortable, you’re on the right track. “You need to take the time to understand how to adjust them and then spend some time fiddling with the bits and adjustments,” Aitken says. “If they’re not adjusted properly you might as well sit on a cardboard box.”

Lastly, focusing for long periods of times can cause eyestrain. Your eyes, too, are controlled by muscles, which need regular rests. If you’re focusing on your screen, every now and then you should move your focus to something further away. LCD screens have made a big difference to the incidence of eyestrain, Aitken says, with less reflection than the old CRT models. Lighting in modern workplaces is also a vast improvement over old-style fluorescent lights. These days, most offices use diffusers on lights, projecting a certain amount of light upwards and a certain amount downwards. The type of light bulbs in use now are also gentler on eyes, with less flicker.

Under the Health and Safety Employment Act 1992, employers have a responsibility to prevent injury at work, and to manage cases where employees are injured. You can find more information on ACC’s site (www.acc.org.nz) on what those responsibilities are. There’s also useful information on the site for employees, who are encouraged to report any discomfort as early as possible and also to be proactive about addressing the problem themselves - taking rest breaks, using micropauses and keeping active.