A short course on using ergonomic principles while using computers in ways that avoid injury to eyes, back, arms and nerves.

1. Ergonomics Training
Lesson 1 – Using Computers Safely
Designed by:
Wayne Pascall

2. Ergonomics – Using Computers Safely
Objectives

3. Ergonomics – Using Computers Safely
Objectives
• Use a desktop computer and its accessories
following safe ergonomic guidelines.
• Adopt the proper posture and equipment when
using the personal computer.
• Use the computer repeatedly in a manner that
will avoid injury to back, hands, nerves and
eyes.
At the end of this course you will be able to:

4. Ergonomics – Using Computers Safely
Lesson 1

5. What is Ergonomics?
• The science of designing and using resources
to maximize safety, efficiency, comfort and
prevent injuries to the human anatomy.
• “Ergonomics, also known as human
engineering or human factors engineering, the
science of designing machines, products, and
systems to maximize the safety, comfort, and
efficiency of the people who use them.
Ergonomists draw on the principles of
industrial engineering, psychology,
anthropometry (the science of human
measurement), and biomechanics (the study of
muscular activity) to adapt the design of
products and workplaces to people's sizes and
shapes and their physical strengths and
limitations.”
http://en.wikipedia.org/wiki/Ergonomics

6. Importance of Ergonomics
• “One of the primary goals of ergonomics is
prevention of workplace illness and accidents.
According to the United States Bureau of
Labor Statistics, more than 60 percent of the
workplace illnesses reported each year are
associated with repetitive stress injuries
Repetitive Strain Injury (RSI). These
injuries result from continuous repetition of
the same motions, for instance screwing or
twisting items on an assembly line. The injury
may be exacerbated by awkward postures,
such as bending or reaching.”
• According to the Bureau of Labor Statistics
(BLS), each year 600,000 workers suffer
serious workplace injuries caused by repetitive
motion and overexertion that require them to
miss time from work.

7. Importance of Ergonomics
• According to the National Academy of Sciences, these injuries cost the
country $45 - $54 billion annually.
http://www.ufcw.org/issues_and_actions/stop_the_pain/how_it_effe
cts_you/ergo_problem.cfm
• The three most common work-related injuries associated with bad
practices in using computers are:
1. Repetitive Strain Injury (RSI),
2. Carpal Tunnel Syndrome
3. Back Injuries

8. Repetitive Strain Injury (RSI)
• This is damage to the nerves in the
arms and hands as a result of
repetitive motions during long
durations (e.g. mouse clicking). The
symptoms are pain in the arms and
hands.
• A group of disorders that most
commonly develop in workers using
excessive and repetitive motions of
the head and neck extremity.

9. Repetitive Strain Injury (RSI)
• Repetitive Strain Injury occurs when
the movable parts of the limbs are
injured. Repetitive Strain Injury
(RSI) usually caused due to
repetitive tasks, incorrect posture,
stress and bad ergonomics. Repetitive
Strain Injury generally causes
numbness, tingling, weakness,
stiffing, and swelling and even nerve
damage. The chief complaint is the
constant pain in the upper limbs,
neck, shoulder and back.“
http://www.safecomputingtips.com/repetitive-strain-injury.html

10. Carpal Tunnel Syndrome
• “A pinched nerve (called the Median
nerve) in the wrist. Carpal Tunnel
Syndrome (CTS) is the inflammatory
disorder that is caused due to
repetitive stress, physical injury or
any other condition that causes the
tissues around the median nerve to
inflated…This ultimately results in
pain, numbness, and tingling
sensation in the wrist, hand, and
fingers.”
http://www.safecomputingtips.com/carpal-tunnel-
syndrome.html

11. Musculoskeletal Disorders
• Injuries to the spine and muscles due
to an unnatural or unhealthy posture
while using the computer.

12. Other Disorders and Injuries
• Eyestrain, Eye fatigue, Poor blood
circulation, Swollen ankles.

13. Positive Work Habits When Using The Computer
Eyesight
1. Position monitor 18” to
24” Away (approximately
arm’s length) and about
15° to 30° below your
line of sight.
2. Reduce glare - Don’t let light
shine in your eyes or
on your screen.
3. Adjust the angle of screen to
your line of vision.
4. Blink! Look away from the
screen and focus on distant
objects periodically.

14. Positive Work Habits When Using The Computer
Posture
1. Get a chair that properly
supports your back from
pelvis to shoulder blades. Sit
all the way back in the chair
against the backrest for
support.
2. Let your arms fall
naturally (sometimes a chair
without an arm rest is
better), elbows bent slightly
more than 90°.
4. Keep your knees equal to,
or lower, than your hips with
your feet supported
3. Adjust the chair height so
that feet are flat on the floor
and legs bent slightly more
than 90°.

15. Positive Work Habits When Using The Computer
Keyboard and Mouse
• Strike the keys softly.
• Glide your hands over the keyboard.
• Rest your palms on a palm rest in
between keystrokes, but don't fix your
wrists or palms on the palm rest while
keying.
• Keep your wrists straight and relaxed.
• Reduce risk of RSI by limiting
repetitive motions - avoid Excessive
clicking of mouse by using the aid of
voice recognition software and
macros.
Negative tilt - Slope keyboard
slightly down away from you

16. Positive Work Habits When Using The Computer
Pace, Duration and Exercises
• Don't sit in one position at the
computer for extended periods. Take
stand and stretch breaks occasionally.
• Occasional breaks accompanied with
simple stretches can help prevent
fatigue and injury:
• Stretches:
Neck and Shoulders
Hands and Wrists
Upper and Mid-Back
Lower Back
Legs
Hips
Ankles

17. Positive Work Habits When Using The Computer
Lifting
• Prevent back injuries by lifting heavy
articles properly.
• Since the thigh muscles are stronger
than the back muscles, lift using the
legs rather than the back.

18. Positive Work Habits When Using The Computer
For More Information
• OSHA (Occupational Safety & Health Administration) U.S. Department
of Labor
http://www.osha.gov/SLTC/etools/computerworkstations/index.html
http://www.osha.gov/SLTC/etools/computerworkstations/checklist.html

19. Ergonomics – Using Computers Safely
Summary

20. Ergonomics – Using Computers Safely
Summary
• How to use a desktop computer and its
accessories following safe ergonomic
guidelines.
• How to adopt the proper posture and
equipment when using the personal computer.
• How to use the computer repeatedly in a
manner that will avoid injury to back, hands,
nerves and eyes.
You have just learned:

21. Ergonomics – Using Computers Safely
Quiz

22. Ergonomics – Using Computers Safely
Quiz
• Carpal Tunnel Syndrome (CTS) and Repetitive Strain Injury (RSI) are
injuries to the nerves caused by repetitive motions of the arms and
hands during long durations.
True or False?

23. Ergonomics – Using Computers Safely
Quiz
• What can a computer user do to prevent Carpal Tunnel Syndrome and
Repetitive Strain Injuries?
Question

24. Ergonomics – Using Computers Safely
Quiz
• While using the computer, sitting upright all the way back in the chair
against the backrest will prevent injury to:
 Eyes
 Spine and back
 Fingers
 Arms
Multiple Choice

25. Ergonomics – Using Computers Safely
Quiz
• What can a computer user do to prevent eyestrain and other eye
injuries?
Question

26. Ergonomics – Using Computers Safely
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