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Does the use of laptops violate the display screen equipment regulations?

Display Screen Equipment Regulations have been in force since 1 January 1993. Since then, employers should have been undertaking risk assessments of computer (Display Screen Equipment) workstations. The equipment in use at these workstations should comply with the minimum requirements as set out in the Schedule to the regulations. Employers should have been complying with the obligations set out in the regulations, such as provision of eye tests and training.

In April 2003, the Health and Safety Executive (HSE) published amended guidance on these regulations, entitled 'Work with display screen equipment: Health and Safety (Display Screen Equipment) Regulations 1992 as amended by the Health and Safety (Miscellaneous Amendments) Regulations 2002' . One of the key changes has been that portable display screen equipment (DSE) such as laptop computers is now subject to the DSE Regulations. The reason for this is that portable DSE was being used for long periods and as replacements for desktop computers. A large number of laptops were no longer being used only as ïportable' equipment. Users were facing specific musculoskeletal disorders associated with the prolonged use of laptop computers.

Laptop computers were introduced into the workplace for reasons of portability. They were initially designed to be taken 'on the job' where they were used for small data entering tasks, requiring only short periods of computer input. Use of laptop computers has been increasing rapidly since the 1990s. This increase has been happening both in the number of laptop computers being used and in the number of hours individual people have been using laptop computers.

The increase in the popularity of laptops has been due mainly to two key factors. The first factor is technological improvements in the performance of laptops and communication technologies that have made it possible for people to be able to work away from traditional office environments. This has been accompanied by a reduction in prices. The second factor is the changes in working practices, such as hot desking, linked to the increased cost of office space.

It is easily noticeable from advertising in the media that there is a trend being set to replace desktop computers with laptop computers, initially in offices and then in the home environment.

According to IDC,, which is the premier global market intelligence and advisory firm in the information technology industry, unit shipments of laptops have doubled from about 3.6 million in the first quarter of 1998 to about 7.2 million in the first quarter of 2002. In the first quarter of 2003 worldwide shipments of laptops reached 8.57 million. This trend is not slowing down. The year on year gain in laptop sales is now nearly 1 million units whilst the sale of desktop computers (in office environments) is declining steadily by about 12% annually.

Laptop computers may not be suitable for prolonged use because of the smaller size of screen and keyboard, and the lack of separate keyboard and screen position adjustment. The independent adjustment of screen and keyboard is important to allow users to position the tactile and visual interaction components in a way,, which encourages a good posture. A large industry has developed around research to supply adjustable furniture for the office situation. Desktop computers have separate screens and keyboards to allow independent adjustment of their heights and distances. However, it appears that computer manufacturers may have taken a retrograde step with laptop designs. Unlike desktop computers, laptop screens are usually fixed to the keyboard with a hinge. This allows for the angle of viewing to be adjusted but does not allow independent adjustment of screen and keyboard distance and height. Given these physical constraints, it was assumed that the user would be required to compromise their typing posture either by increased neck flexion, in order to see a lower screen, and/or by increased shoulder and elbow flexion, in order to reach a higher keyboard.

Unless checked, the current habitual prolonged use of laptop computers is likely to cause postural problems and consequently result in significant increases both in the number of musculoskeletal disorders (MSD) and in their severity.

The Health and Safety Executive in their revised guidance document to the Display Screen Equipment Regulations (April 2003) have recognised the problem of laptops being used as permanent computing equipment. On page 52 this document states:

'Portable (DSE), such as laptop and notebook computers, is subject to the DSE Regulations if it is in prolonged use.

Increasing numbers of people are using portable DSE as part of their work. While research suggests that some aspects of using portable DSE are no worse than using full-sized equipment, that is not true of every aspect. The design of portable DSE can include features (such as smaller keyboards or a lack of keyboard separation), which may make it more difficult to achieve a comfortable working posture. Portable DSE is also used in a wider range of environments, some of, which may be poorly suited to DSE work.

As with full-sized DSE, portables in prolonged use (and the workstations and working environments where they are used) are required to comply with the Schedule (to the Regulations).

Potential problems with the use of Laptop Computers

The rapid spread of laptop computers ran ahead of the scientific research into the health and safety aspects of their use. However, Leon Straker at Curtin University in Australia cites a recent study, which found that 60% of laptop users reported musculoskeletal discomfort.

Features of laptop computers differ from those of desktop computers in key human machine interaction respects , which create the potential problems. These are: the screen, the input device, the connection of screen to keyboard and finally the environments in, which they are used.

Screen

Laptop screens are flat screens, which until very recently had poorer clarity and a restricted lateral angle of viewing. The results of these are common complaints of difficulty in viewing laptop screens. This can lead to visual discomfort and, as the visual and musculoskeletal systems are closely linked, it can also lead to musculoskeletal discomfort.

Keyboard and Input Devices

Most laptops currently available use a reduced size keyboard on a thick flat base, , which raises it relatively high above the worksurface yet with no slope or difference in height between keys in each row. This often requires users to raise their wrists and hands to reach keys in the back row as shown in the following picture. This put strains on wrist, hand and shoulder muscles.

Laptops use a track pad or mini joystick as pointing devices. Pointing devices in laptops require more accurate but smaller and finer control movements than those in desktop computers. These in turn can put greater strain on hand muscles for movement control, and forearm muscles for stabilising hands.

Fixed connection of screen to keyboard

Most current laptops have the screen attached to the main body of the keyboard of the computer. This presents a severe restriction to the user in choosing a comfortable position for the keyboard (laterally) and the screen (laterally and height wise).

Both the visual system and hand movements have their own comfortable ïreach' zones,, which vary from one user to another. With desktop computers, where the keyboard and other input devices are separate from the screen, it is possible for the user to place these three components in comfortable reach zones. However, as the laptop screens are permanently attached to keyboards and input devices, users who prefer longer eye to monitor distance have to key with extended arms or compromise the visual distance in order to achieve a more comfortable arm posture.

The height of the screen is also fixed in relation to the worksurface. The low screen can cause a neck strain even though it results in less visual strain. This may create some musculoskeletal problems for some people. However the key problem is that users have no choice in selecting a screen height, which is comfortable for them.

Health and Safety (Display Screen Equipment) Regulations

It is generally agreed that, as can be seen from the picture above, people using laptops adopt a hunched posture where their neck is bent (flexed), head is lowered and protrudes forward, shoulders roll in and chest appears sunken. Consequently the spine loses its normal S-shape and is arched forward. Such postures are considered to give rise to musculoskeletal discomfort and disorders. It must be noted that screens positioned above eye level can cause greater problems such as neck and shoulder pain or disorder.

Environment

Often if the laptops are truly used as portable equipment, they will be used away from more controlled environments such as offices. In such environments the users may have to use the laptops on worksurfaces that are too high or too low, with too little lighting or with reflections and glare present. All such factors may force the user to adopt non-conventional postures to minimise the effects of these factors. For example in order to avoid glare the user may rotate the laptop,, which in turn can force the user to adopt a twisted back posture in order to use the keyboard.

Additional problems with laptops are that they have to be transported/carried by the users. Even though an average laptop weighs about 4kg, by the time the user has to carry power adapters and other accessories, the weight soon builds up. If they are carried in inappropriate bags, they can create other musculoskeletal problems such as back pain.

There is another unexpected risk associated with the laptop computers. HSE states that there is a risk of theft, possibly involving assault. Hence employers have to inform their employees how to minimise such risks.

In conclusion, the design and use of laptop computers can result in increased visual and musculoskeletal disorders compared with desktop computers. The main problems are likely to be visual discomfort and neck and upper limb complaints, all due to possible poorer clarity of display, restricted viewing angles, lack of tilt of keyboard, and lack of independent adjustment of position and height of keyboard and screen. All these problems are likely to be exacerbated when laptop computers are used away from controlled office environments.

What can be done to minimise the effects of risk associated with the use of laptop computers

The best solution is not to use laptops as replacements for desktop computers.

If laptops are to be used in the office environment (either as a replacement for desktop computers or when hotelling/hot desking) they need to be used with a separate high clarity height adjustable screen, a keyboard and an independent pointing device (such as an external mouse) at a docking station. Such an arrangement would probably be the best ergonomic way of avoiding many of the risks associated with the prolonged use of laptop computers. This solution is also advocated in the latest HSE guidance document.

Failing this option, there are other possibilities such as raising the laptop on a special stand or on raiser blocks to provide a more convenient height for the screen (instead of another independent screen) and using a separate keyboard and pointing device.

Fortunately there are also laptop stands, , which allow the user to place the laptop on the stand and use a separate keyboard and pointing device. Such stands are height adjustable and they facilitate a good screen position for the users, as shown below.

Health and Safety (Display Screen Equipment) Regulations

As discussed earlier, the prolonged use of laptops outside controlled office environments would place the user at a higher risk than when they are used in offices. Therefore, users such as executives, professionals, academics and sales people who are likely to use their laptops at other people's workplaces and in hotel rooms do need a portable height adjustable laptop holder with a slim keyboard. Such stands should be as light as possible, fit in the laptop computer case and provide a document holder between keyboard and screen.

Finally, if you must buy a portable computer, the following list includes important factors:

Look for a light weight one including accessories, if possible 3kgs or less.
Choose one with a large screen.
If possible, choose one with a detachable screen.
Specify a long life battery to avoid having to carry power transformers.
Provide light weight carrying cases with shoulder straps for ease of carrying but without computer logos on the outside to minimise the risk of theft.
Look for tilt adjustable keyboards on laptops.
Look for a casing, which incorporates a space (wrist pad) between keyboard and front edge.
Choose one with a docking facility.
Choose one with the ability to plug in both an external keyboard and a mouse simultaneously.
Choose one with non slip feet to avoid sliding on worksurfaces.
Choose one with large memory and high speed to suit needs of tasks and to avoid stress to the user.
If applications require significant input via a pointing device, choose one with an external mouse, roller ball or touch pad, rather than a 'nipple' trackball or isometric joystick.

The FIRA Ergonomics Unit carries out risk assessments to help companies comply with health and safety regulations. Identifying problems and offering ergonomics solutions not only ensures regulatory compliance but also increases efficiency and productivity. Ergonomics advice in furniture specification and selection and the planning of office layouts is also available.

In 2000 the FIRA Ergonomics Excellence award was introduced to give specifiers confidence that products marketed as ïergonomic' meet genuine criteria. To gain the award, products must be appropriately designed in terms of safety, comfort and well-being. They must also comply with health and safety regulations and meet or exceed the minimum European, British and FIRA standards on ergonomics. In addition, the manufacturer must have a quality management system and an environmental policy.

For further information on the services of the Ergonomics Unit or the Ergonomics Excellence Award, please contact FIRA's Senior Ergonomist, Levent Çaglar

on +44 (0) 1438 77 77 00.

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