Introduction to Health and Safety at Work

Musculoskeletal problems
Tenosynovitis is the most common and well-known prob-
lem which affects the wrist of the user. The symptoms 
and effects of this condition have already been covered. 
Suffi ce it to say that if the condition is ignored, then the 
tendon and tendon sheath around the wrist will become 
permanently injured. Tenosynovitis, better known as RSI, 
is caused by the continual use of a keyboard and can 
be relieved by the use of wrist supports. Other WRULDs 
are caused by poor posture and can produce pains in 
the back, shoulders, neck or arms. Less commonly, pain 
may also be experienced in the thighs, calves and ankles. 
These problems can be mitigated by the application of 
ergonomic principles in the selection of working desks, 
chairs, foot rests and document holders. It is also import-
ant to ensure that the desk is at the correct height and 
the computer screen is tilted at the correct angle to avoid 
putting too much strain on the neck. (Ideally the user 
should look down on the screen at a slight angle.)
The keyboard should be detachable so that it can 
be positioned anywhere on the desktop and a correct 
posture adopted while working at the keyboard. The chair 
should be adjustable in height, stable and have an adjust-
able backrest. If the knees of the user are lower than the 
hips when seated, then a footrest should be provided. 
The surface of the desk should be non-refl ecting and 
uncluttered but ancillary equipment (e.g. telephone and 
printer) should be easily accessible.
Visual problems
There does not appear to be much medical evidence that 
DSE causes deterioration in eye sight, but many users 
suffer from visual fatigue which results in eye strain, sore 
eyes and headaches. Less common ailments are skin 
rashes and nausea.
The use of DSE may indicate that reading spec-
tacles are needed and the Regulations make provision for 
this. It is possible that any prescribed lenses may only be 
suitable for DSE work since they will be designed to give 
optimum clarity at the normal distance at which screens 
are viewed (50–60 cm).
Eye strain is a particular problem for people who 
spend a large proportion of their working day using 
display screen equipment. A survey has indicated 
that up to 90% of DSE users complain of eye fatigue. 
Unnecessary eye strain can be reduced by the following 
additional steps to those already identifi ed in this section:
➤
Train staff in the correct use of the equipment
➤
Ensure that a font size of at least 12 is used on the 
screen, and
➤
Ensure that users take regular breaks away from the 
screen (every 20 minutes).
The screen should be adjustable in tilt angle and 
screen brightness and contrast. Finally, the lighting 
around the workstation is important. It should be bright 
enough to allow documents to be read easily but not too 
bright so that either headaches are caused or there are 
refl ective glares on the computer screen.