Working with computer
Working with computer monitors could cause various health complaints such as headaches, neck pains, with similar symptoms in the wrists, arms, back and eyes. This folder explains the origins of health complaints and how one can recognise and perhaps prevent such symptoms. Additionally, you will find information on what to do if you experience such problems.
What causes have health complaints? Much research has gone into finding the
nature and cause of such disorders. At
present, we know that health complaints can
develop by repeating the same motions too
frequently while working. These motions are
common in certain professions, for example,
in painters, packers, plasterers, musicians,
hairdressers and people who work with
monitors. The chances of developing health
complaints are greater with heavy workloads,
poor posture and incorrect work procedures.
A combination of work and hobbies, such as
painting your house or surfing the Internet,
could cause health complaints. Whether one
actually develops complaints will depend on
ones physical fitness and work procedures.
Some people suffer such disorders; others do
not. At first, the pain goes away, only to return
at a later stage when it continues during the
evening and, ultimately, beyond the weekend.
Recuperation is often time consuming and the
symptoms reappear quickly.
The following sections describe what you can
do to prevent or limit health complaints.
Health complaints and Working with
In tackling health complaints for people who
work with monitors, the following aspects are
Work tasks Working times Workload Workstations Work procedures
Work tasks and times
To reduce possible symptoms, it is important
to alternate regularly between working with
monitors and other tasks. Examples of other
activities include answering the telephone,
delivering the post, holding progress
discussions or making photocopies, reading
and writing. For those who cannot alternate
tasks, it is important to take a ten-minute
break once an hour. Taking half-hour breaks
would be even better! If it were possible to
alternate between working at a monitor and
doing other jobs, then a short break every two
hours would be desirable. Tasks involving the
use of computer monitors should not exceed
five or six hours a day.
Various factors can cause one to feel the pressures of work. The pressure of work occur, for example, when the work is tied to
deadlines or when the task at hand requires more from you than you can handle. Other causes are work relationships with colleagues and managers and frequent interruptions during work. If you suffer from these, discuss the problem areas with your manager and try
to resolve them together Occasionally experiencing work pressure is not a problem. This works to dispel the
days boredom. In such situations, try to do your work in a relaxed manner. If this does not work, a training course in learning to cope with the pressures of work could help.
Arrange your workstation so that you can assume a relaxing working posture. Points of interest are the desksize, the chair, the position and settings of the monitor, along with the keyboard, mouse, incoming daylight and the location of lighting fixtures. It is also important to organise the material on ones desk, so there are no unnecessary items and so you do not have to search endlessly for the items you need. Below is a discussion of things to bear in mind when buying or using various work materials. This folder includes a checklist for an individual assessment of how to set up your workstation.
1.1.1 The Desk
Your desk should be spacious enough to accommodate a monitor with a keyboard and a mouse. In addition, should provide sufficient space for other materials. When working with computer monitors, the lower arms should have ample room to rest on the desktop.
In order to work directly in front of the
monitor, it is important that there are no
obstacles under the desk that restrict leg
movement or keep you from stretching your
legs. You should be able to sit with your chair
close to the desk, so you dont have to sit on
the edge of your seat. This requires a desk
whose right side is at least 60 centimetres and
a desk chair with short armrests. There are
additional requirements for the layout of CAD
workstations. Although these are not
discussed here, you can obtain information on
these requirements from the AMD.
The Desk Chair
A good desk chair will have vertically
adjustable seats and armrests. The seat depth
should be capable of being adjusted by the
seat itself. Some chairs also have horizontally
adjustable armrests. Adjust the chair to
provide adequate support for your thighs, the
small of the back and your arms. Make sure
that the back support does not interfere with
your shoulders. The adjustment you choose
should depend entirely on your height and
posture. Slender people should always choose
chairs with horizontally adjustable armrests.
This means that the distance between the
armrests can be reduced. A more active sitting
posture is possible using chairs with synchro-
mechanisms (wobble position). However, not
everyone finds this comfortable. Desk chairs
should meet the minimum standards of the
Dutch standard (NPR 1813, 2004). Among
other things, this standard prescribes the
adjustment reach of the seat, chair back and
armrests, along with the required
1.1.2 The Monitor Nowadays desktop monitors are increasingly larger. Besides larger screens, such monitors have greater depths. The required reading distance is also greater. The recommended viewing distance for a 15-inch monitor is between 55 and 75 centimetres; for a 19-inch screen, between 70 and 95 centimetres. In general, one can say that the larger the monitor, the deeper the desk should be. In such cases, a standard desk of 80 centimetres will not be wide enough. When desks are wider or deeper, they could interfere with the walking space around your desk. Before buying a new monitor, find out whether you really need such a monitor for the work that you do.
Place the monitor directly in front of you, with
the top edge of the screen at eye level.
Smaller monitors will have to be elevated.
Larger monitors can usually be placed on a
desk without raising the height.
The ideal contrast is one in which no daylight
or light from other sources reflects on the
screen. Looking directly into the light will
make reading from the screen more difficult.
The Keyboard and Mouse In general, standard, rectangular qwerty keyboard is satisfactory. Avoid hitting the keys with too much force. This could cause problems.
The mouse should fit comfortably in the hand.
This is usually the case if the mouse is not too
thick or when it is symmetrical in shape with
no sharp edges. The speed of the mouse
should be aligned to personal use and the
cord should be sufficiently long. Regularly
clean the mouse mechanism to avoid
unnecessary hand or arm movements. It is
difficult to say whether a so-called ergonomic
mouse, a trackball, or pen would be more
suitable for you personally. If necessary,
consult your company doctor or your ARBO
Notebook/laptop If you work longer than two hours a day with a notebook / laptop, additional accessories such as a laptop support and a separate keyboard and mouse are required.
Other Risk Factors Avoid working in cold air currents. Do not position your desk too close to a window or other supply air defuser. If noise is a problem at your place of work, try to find out what causes it. Consult your colleagues and supervisors on ways to solve the problem.
Work Procedures Here are several brief tips for developing good work habits. First, adjust your chair to suit your height.
Do not worry about the height of your desk. The thighs should be horizontal and your feet on the floor directly in front of you.
Adjust the seat depth of the chair and the height of the chair back and armrests. Make sure that the backs of the knees remain free with good support in the small of your back. The armrests should not push the arms up.
Then adjust the desk chair for the correct working height. The armrests will be at the same level as the desktop. If your feet do not rest flatly on the floor, use a footrest. Do not use the frame of the chair as a foot support!
Your lower arms should rest on the armrests or on the desktop. Make sure that this does not push your shoulders up.
Keep your hands and wrists in a neutral position, if possible. Do not turn your hands too much in one direction or the other and do not lift your hands when using the mouse or typing.
Do not use excessive pressure when hitting the keys!
Sit straight and make sure that the monitor is not too low or too high. The top edge of the screen should be at eye level.
Consider using a document holder beside or under the screen. This will do away with the need to bend the neck for long periods.
Do not clamp the telephone between your head and shoulder. You sh