HEALTH AND SAFETY ISSUES IN A COMPUTER
ENVIRONMENT (ERGONOMICS)
Ergonomics is the science of matching workplace conditions and job demands
to the capabilities of the working population. An effective and successful match
assures high productivity, avoidance of illness and injury, and increased
satisfaction among the workforce.
Ergonomics, further, refers to assessing those work-related factors that may
pose a risk of musculoskeletal disorders and recommendations to alleviate them.
Common examples of ergonomic risk factors are found in jobs requiring
repetitive, forceful, or prolonged exertions of the hands, prolonged awkward
postures etc.
Ergonomic stress areas in computing environments include:
1 . Eyes
2. Neck
3. Shoulders
4. Elbow
5. Wrist
6. Hand
7. Back/Spine
Resulting injuries are called Cumulative Trauma Disorders
(CTD) or Repetitive
Strain Injuries
(RSI) or Musculoskeletal Disorders (MSD).
EXAMPLES OF MSDs
1 . REPETITIVE STRAIN INJURIES WHICH INCLUDE:
CARPAL TUNNEL SYNDROME- Irritation of the median nerve, which
runs through a bony channel in the wrist called the carpal tunnel.
Usually results from excessive flexing or twisting of the wrist.
TRIGGER FINGER SYNDROME- Tendons in the fingers become
inflamed, causing pain, swelling, and a loss of dexterity.
HAND/ARM VIBRATION SYNDROME- Stinging, numbness, paleness,
loss of dexterity in the hand/arm. It is related to a condition caused by
repeated and frequent use of hand-held vibrating tools.
TENDONITIS- An inflammation of the tendon. Typically occurs in the
shoulder, wrist, hands, or elbow.
PRECAUTIONARY MEASURES
o Adjust keyboard height so that shoulders can relax and allow arms to rest
at the sides.
o The keyboard should be close to the user to avoid extended reaching.
o Forearms should be parallel to the floor (approximately 90 degree angle at
elbow).
o Mouse should be placed adjacent to the keyboard and at the same height
as the keyboard (use articulating keyboard tray if necessary).
o Do not rest the hand on the mouse when you are not using it. Rest hands
in your lap when not entering data.
2. EYE STRAIN
The eyes become strained as a result of poor lighting, glare or viewing
from uncomfortable positions. Focusing on the screen at close range and
for long periods can cause eyestrain, headaches, and double vision.
PRECAUTIONARY MEASURES
o Take a 1 5-minute break every hour or two
o Minimize reflected glare on the screen by keeping the screen away from
windows and other sources of bright light or tilted at right angles from
windows.
o Purchase an antiglare screen/shield for your screen
o The screen should be three or four times brighter than the room light.
o Bigger monitors cause less eyestrain than small ones.
o Clean the screen regularly.
o Position the monitor directly in front of user to avoid excessive twisting
of the neck.
o Position the monitor approx. 20-26 inches (arm’s length) from user.
o Tilt the top of the monitor back 1 0 to 20 degrees
o The top of the viewing screen should be at eye level when the user is
sitting in an upright position.
3. BACK AND NECK PAIN
Sitting for long periods of time can cause increased pressure on the
intervertebral discs. Sitting is also hard on the feet and legs. Gravity tends to
pool blood in the legs and feet and create a sluggish return to the heart.
PRECAUTIONARY MEASURES
o The monitor should be able to tilt and swivel
o The keyboard should be detachable such that you can sometimes place it
on your lap.
o Don’t stay in one static position for extended periods of time i.e. “Dynamic
sitting”.
o Adjust height of backrest to support the natural inward curvature of the
lower back.
o Adjust height of chair such that the feet rest flat on the floor.
o Sit upright in the chair with the lower back against the backrest.
EFFECTS OF ELECTROMAGNETIC FIELDS
Video display terminals generate electromagnetic fields (EMF) emissions,
which can pass through the human body.
MEASURES
Use low-emission monitors especially the modern screens
SYMPTOMS OF MUSCULOSKELETAL DISORDERS
Muscle fatigue or pain
Aching
Burning
Numbness
Stiffness
Tingling/stinging
