Understanding Ergonomics
Understanding Ergonomics
Here are some tips for setting up a healthy work environment.
Keyboard
When you use the keyboard, your shoulders should be relaxed. Your upper arm and
forearm should form an approximate right angle, with your wrist and hand in roughly
a straight line.
Change hand positions often to avoid fatigue. Some computer users might develop
discomfort in their hands, wrists, or arms after intensive work without breaks. If you
begin to develop chronic pain or discomfort in your hands, wrists, or arms, consult a
qualified health specialist.
Mouse
Position the mouse at the same height as the keyboard and within a comfortable reach.
Chair
An adjustable chair that provides firm, comfortable support is best. Adjust the height
of the chair so your thighs are horizontal and your feet are flat on the floor. The back of
the chair should support your lower back (lumbar region). Follow the manufacturer s
instructions for adjusting the backrest to fit your body properly.
You might have to raise your chair so that your forearms and hands are at the proper
angle to the keyboard. If this makes it impossible to rest your feet flat on the floor, use
a footrest with adjustable height and tilt to make up for any gap between the floor and
your feet. Or you can lower the desktop to eliminate the need for a footrest. Another
option is to use a desk with a keyboard tray that s lower than the regular work surface.
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Display
Arrange the display so that the top of the screen is slightly below eye level when you re
sitting at the keyboard. The best distance from your eyes to the screen is up to you,
although most people seem to prefer 18 to 28 inches (45 to 70 cm).
Position the display to minimize glare and reflections on the screen from overhead
lights and nearby windows. If possible, use a tiltable display stand. The stand lets you
set the display at the best angle for viewing, helping to reduce or eliminate glare from
lighting sources you can t move.
Thighs tilted
slightly
Shoulders
relaxed
Screen positioned to
avoid reflected glare
Forearms and
hands in a
straight line
Forearms level
or tilted slightly
Lower back
supported
Feet flat on the floor
or on a footrest
Top of the screen at or
slightly below eye level
(You may need to adjust
the height of your display
by raising or lowering
your work surface)
Clearance under
work surface
18–28 in. (45–70 cm)
More information about ergonomics is available on the web:
www.apple.com/about/ergonomics
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Avoid Hearing Damage
WARNING:
Permanent hearing loss may occur if earbuds or headphones are used at
high volume. You can adapt over time to a higher volume of sound that may sound
normal but can be damaging to your hearing. If you experience ringing in your ears
or muffled speech, then stop listening and have your hearing checked. The louder the
volume, the less time required before your hearing can be affected. Hearing experts
suggest that to protect your hearing:
Limit the amount of time you use earbuds or headphones at high volume
Avoid turning up the volume to block out noisy surroundings
Turn the volume down if you can t hear people speaking to you