HP Pavilion XT545 Manual

Safety & Comfort Guide
Also available at www.hp.com/ergo
Document Part Number: 297660-002
This guide describes proper workstation setup, posture, and
health and work habits for computer users. In addition, this
guide contains electrical and mechanical safety information
applicable to all HP products.

© 2002 Hewlett-Packard Company
Product names mentioned herein may be trademarks of their respective companies.
Hewlett-Packard Company shall not be liable for technical or editorial errors or omissions
contained herein or for incidental or consequential damages in connection with the
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ÅWARNING: Text set off in this manner indicates that failure to follow directions could
result in bodily harm or loss of life.
ÄCAUTION: Text set off in this manner indicates that failure to follow directions could result
in damage to equipment or loss of information.
Safety & Comfort Guide
Second Edition (September 2002)
Document Part Number: 297660-002

Safety & Comfort Guide iii
WARNING
Å
There may be a risk of serious physical injuries from
working at your computer workstation. Read and follow
the recommendations in this Safety & Comfort Guide to
minimize the risk of injury and to increase your comfort .
Some studies have suggested that long periods of typing,
improper workstation setup, incorrect work habits,
stressful work conditions and relationships, or problems in
your personal health may be linked to injuries. These
injuries could include carpal tunnel syndrome, tendinitis,
tenosynovitis, and other musculoskeletal disorders.
The warning signs of these disorders can occur in the
hands, wrists, arms, shoulders, neck, or back, and can
include:
❒Numbness, burning, or tingling
❒Soreness, aching, or tenderness
❒Pain, throbbing, or swelling
❒Tightness or stiffness
❒Weakness or coldness
Symptoms may be felt during typing, while using a mouse,
or at other times when no work with the hands is being
performed, including during the night when these
symptoms might awaken you. If you experience these
symptoms, or any other persistent or recurring pain or
discomfort that you think may be related to using a
computer, you should promptly consult a qualified
physician and, if available, your company’s health and
safety department. The earlier a problem is properly
diagnosed and treated, the less chance there is that it will
progress to a disabling condition.
The following pages describe proper workstation setup,
posture, and health and work habits for computer users.
In addition, this Guide contains product safety information
applicable to all HP products.

iv Safety & Comfort Guide
Warning

Safety & Comfort Guide v
Contents
Warning
1 Promoting a Safe and Comfortable
Work Environment
Important Choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2
2 Finding Your Comfort Zone
A Range of Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2
Feet, Knees, and Legs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3
Back. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–4
Shoulders and Elbows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–5
Forearms, Wrists, and Hands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–6
Eyes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–8
3 Arranging Your Work Area
Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–2
Keyboard and Pointing Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–4
Arm Supports and Palm Rest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–6
Papers and Books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–8
Phone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–9
4 Working in Comfort
Using a Notebook Computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–2
Typing Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–3
Pointing Style. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–4
Using a Keyboard on a Sofa or Bed . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–5
Taking Breaks and Varying Your Tasks . . . . . . . . . . . . . . . . . . . . . . . . 4–6
Monitoring Your Health Habits and Exercise . . . . . . . . . . . . . . . . . . . . . 4–7
5 Organizing Your Adjustments
From the Ground Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–1
From the Top Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5–1
6 Your Safety & Comfort Checklist
Seated Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–1
Shoulders, Arms, Wrists, and Hands. . . . . . . . . . . . . . . . . . . . . . . . . . . 6–1
Eyes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–2
Typing Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–2
Keyboard and Pointing Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–3

vi Safety & Comfort Guide
Contents
Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–3
Notebook Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–4
General Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6–4
7 Electrical and Mechanical
Safety Information
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–1
Product Safety Policy and General Practice . . . . . . . . . . . . . . . . . . . . . 7–1
Installation Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–2
General Precautions for HP Products . . . . . . . . . . . . . . . . . . . . . . . . . . 7–3
Precautions for Portable Computer Products . . . . . . . . . . . . . . . . . . . . 7–6
Precautions for Server and Network Products. . . . . . . . . . . . . . . . . . . . 7–7
Precautions for Products with Hot-Pluggable Power Supplies . . . . . . . 7–9
Precautions for Products with External Television Antenna Connectors 7–9
Precautions for Products with Modems,
Telecommunications, or Local Area
Network Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–11
Precautions for Products with Laser Devices . . . . . . . . . . . . . . . . . . . 7–11
Symbols on Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7–13
Appendix
For More Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A–1

Safety & Comfort Guide 1–1
1
PROMOTING ASAFE AND COMFORTABLE
WORK ENVIRONMENT
Adjust into Your Comfort Zone
Whether you are an adult sharing a computer at work,
or a student sharing a computer at school or at home,
each time you sit down, adjust the environment to your
needs. Adjust the tilt of your monitor, use a box as a
footrest, a blanket on the seat to raise your chair
height—whatever you need to adjust into your comfort
zone.

1–2 Safety & Comfort Guide
Promoting a Safe and Comfortable Work Environment
Important Choices
Posture, lighting, furniture, work organization, and other
work conditions and habits cay affect the way you feel and
how well you work. By adjusting your work environment
and personal practices, you may be able to minimize
fatigue and discomfort, and reduce the risk of resulting
strains that some scientists believe can lead to injury.
Whenever you use a computer, you make choices that
can affect your comfort and potentially your safety. This is
true whether you use a desktop keyboard and monitor in
an office, notebook computer in a college dormitory,
wireless keyboard on your lap, or handheld at the airport.
In every case, you choose your working posture and your
body’s position relative to your computer, phone,
reference books, and papers. You may also have some
control over lighting and other factors.
Take Action for Safety and Comfort
Many factors in our work environment determine whether
we work efficiently and in a manner that promotes good
health and safety. By considering, acting on, and
periodically reevaluating the recommendations in this
Guide, it is possible to create a safer, more comfortable,
healthful, and efficient work environment.
Students and Teachers
The recommendations in this Guide apply to students of
all ages. Learning to adjust your work area and finding
your comfort zone when you first learn to use a computer
is a lot easier than trying to break incorrect work habits
after years of computer use. Teachers, have your
students work in teams to find inventive solutions when
adjustable furniture designed for computer use is not
available.
IMPORTANT
Some scientists
believe that working
intensely, or for a
long time in
uncomfortable or
unnatural positions,
may pose risks,
such as those
mentioned in the
Warning at the
beginning of this
Guide. The
information included
in this Guide is
designed to help you
work more safely by
recommending ways
to work more
comfortably and
effectively.
TIP
Self check
After reviewing the
information in
Chapters 1 through
5, double-check your
postures and habits
using Chapter 6,
“Your Safety &
Comfort Checklist.”

Safety & Comfort Guide 1–3
Promoting a Safe and Comfortable Work Environment
Key Principles
To promote safety and comfort, follow these principles whenever
you use your computer.
ADJUST
◆Adjust your body position and your work
equipment.
◆There is no one “right” position. Find your
comfort zone, as described in this Guide,
and when working at your computer,
frequently adjust within this zone.
MOVE
◆Vary your tasks so that you can move
around; avoid sitting in one posture all day.
◆Perform tasks that require walking.
RELAX
◆Build positive relationships at work and
home. Relax and strive to reduce sources of
stress.
◆Stay aware of physical tension such as
clenching your muscles and shrugging your
shoulders. Continually release tension.
◆Take frequent, short breaks.

1–4 Safety & Comfort Guide
Promoting a Safe and Comfortable Work Environment
LISTEN
◆Listen to your body.
◆Pay attention to any tension, discomfort, or
pain you may feel, and take immediate
action to relieve it.
REMEMBER
◆Exercise regularly and maintain general
fitness; this will help your body withstand the
rigors of sedentary work.
◆Respect any medical conditions you may
have or other known health factors. Adjust
your work habits to accommodate them.

Safety & Comfort Guide 2–1
2
FINDING YOUR COMFORT ZONE
Vary Your Posture
Depending on your tasks, you may find a range of
sitting and standing postures that are comfortable.
Within your comfort zone, change postures often
throughout the day.
Reclined Upright Standing

2–2 Safety & Comfort Guide
Finding Your Comfort Zone
A Range of Positions
Rather than working in a single posture, find your comfort
zone. Your comfort zone is a range of positions that is
generally appropriate and comfortable for your given work
situation.
Move
Sitting still for long periods can cause discomfort and
muscle fatigue. Changing postures is good for many parts
of your body, including your spine, joints, muscles, and
circulatory system.
❒Within your comfort zone, change postures often
throughout the day.
❒Take frequent short breaks: stand up, carefully stretch,
or walk around.
❒Frequently switch to brief tasks that require getting up,
such as retrieving output from a printer, filing
paperwork, or consulting a colleague down the hall.
❒If your furniture offers a wide range of adjustments,
you might find it comfortable to switch back and forth
between sitting and standing positions.
Different Tasks, Different Postures
Your choice of posture within your comfort zone may vary
with your task. For example, you may find a slightly
reclined posture most comfortable for computer tasks,
and a more upright posture more comfortable for tasks
requiring frequent reference to papers or books.
Organizing Your Adjustments
The order in which you make various adjustments to your
body position and work area may vary depending on the
adjustability of your furniture. For tips on how to order your
adjustments, refer to Chapter 5, “Organizing Your
Adjustments.”
TIP
That afternoon
slump
Pay particular
attention to adjusting
your posture in the
afternoon when you
may tend to get
fatigued.
AVOID!
◆Do not sit in one
fixed posture all
day.
◆Avoid slouching
forward.
◆Be sure not to lean
back too far.

Safety & Comfort Guide 2–3
Finding Your Comfort Zone
Feet, Knees, and Legs
Make sure your feet can rest solidly and comfortably on
the floor while sitting. Use an adjustable work surface and
chair that allow your feet to rest firmly on the floor, or use
a footrest. If you use a footrest, be sure it is wide enough
to accommodate different leg positions within your
comfort zone.
Providing Enough Leg Room
Be sure you have sufficient space under your work
surface for your knees and legs. Avoid concentrated
pressure points along the underside of your thigh near the
knee and the back side of your lower leg. Stretch your
legs and vary your leg posture throughout the day.
TIPS
Walk
Get up from your
desk frequently and
take brief walks.
Leg comfort
Vary your leg
positions throughout
the day.
AVOID!
Avoid placing boxes
or other items under
your desk that limit
your leg room. You
should be able to
pull yourself all the
way up to your desk
without interference.
RIGHT
Rest your feet
firmly on the floor
or a footrest.
WRONG!
Do not dangle your
feet and compress
your thighs.

2–4 Safety & Comfort Guide
Finding Your Comfort Zone
Back
Use your chair to fully support your body. Distribute your
weight evenly and use the entire seat and backrest to
support your body. If your chair has adjustable low back
support, match the contours of the chair’s backrest to the
natural curve of your lower spine.
Getting comfortable
Always make sure your lower back is well-supported.
Make sure it feels comfortable in the position in which you
are working.
TIP
Adjust often
If your chair is
adjustable,
experiment with the
adjustments to find
numerous
comfortable
positions, then
adjust the chair
frequently.
AVOID!
If you get a new
adjustable chair, or if
you share a chair
with someone else,
do not assume the
settings are properly
set for you.
RIGHT
Distribute your
weight evenly and
use the entire seat
and backrest to
support your body.
WRONG!
Do not slouch
forward.

Safety & Comfort Guide 2–5
Finding Your Comfort Zone
Shoulders and Elbows
To minimize muscle tension, your shoulders should be
relaxed, not elevated or drooped (refer to Chapter 3, in the
section “Supporting Your Forearms”), and your elbows
should be placed comfortably in relation to your keyboard
height. Position your elbows in a zone that is near the
height of your keyboard's home row (the row that includes
the letter L). Some find it most comfortable to position
their elbows slightly above the height of the home row and
to set the keyboard slope to the lowest (most flat) position.
TIP
Relax
Remember to relax,
particularly in areas
where muscle
tension often builds,
such as your neck
and shoulders.
RIGHT
Turn your chair to the
side to help
determine if your
elbow height is near
the height of your
keyboard's home row.

2–6 Safety & Comfort Guide
Finding Your Comfort Zone
Forearms, Wrists, and Hands
While typing or using a pointing device, keep your
forearms, wrists, and hands in their neutral comfort zone.
You are the best judge of what feels comfortable to you.
One way to find your comfort zone is to completely relax
your arms, wrists, and hands at your sides and notice how
they are positioned. When you lift them up to type, hold
them at or near these same relative positions (their
neutral comfort zone), avoiding bending your wrists
markedly up, down, in or out to the sides, especially
frequently or for long periods of time (refer to Chapter 3, in
the section “Keyboard and Pointing Device”). These
recommendations apply wherever you are—in the office,
at home, traveling—whether you are standing or sitting.
Do Not Anchor Your Wrists
When typing, do not anchor or rest your wrists on your
work surface, your thighs, or a palm rest (sometimes
called a wrist rest). Resting your palms while typing may
be harmful because it can cause you to bend and hold
your wrists and fingers back. It can also apply pressure to
the underside of your wrists. A palm rest is designed to
provide support during pauses, when you are not typing
(such as when you are reading from the screen).
TIP
Split keyboards
If you find it difficult
to type with a
comfortable, neutral
wrist position, you
may want to try a
split keyboard. Be
aware, however, that
improper setup or
posture while using
a split keyboard can
increase marked
bending in your
wrists. So if you try
using a split
keyboard, set it up
properly so your
forearms, wrists,
and hands are in a
comfortable, neutral
position.
AVOID!
Be sure not to rest
your wrists on sharp
edges.
RIGHT
Maintain a
comfortable, neutral
wrist position.
WRONG!
Do not rest your
palms or bend your
wrists markedly down
while typing.

Safety & Comfort Guide 2–7
Finding Your Comfort Zone
TIP
Handhelds
The information in
this section
regarding
comfortable, neutral
forearm, wrist, and
hand positions
applies to users of
handhelds as well,
whether you are
typing with a stylus
or thumb keyboard.
RIGHT
Maintain a
comfortable, neutral
wrist position.
WRONG!
Do not bend your
wrists markedly
inward.

2–8 Safety & Comfort Guide
Finding Your Comfort Zone
Eyes Eyes
Working at your computer for long periods can be a
visually demanding task and may cause your eyes to
become irritated and fatigued. Therefore, you should give
special attention to vision care, including the following
recommendations:
Resting Your Eyes
Give your eyes frequent breaks. Periodically look away
from the monitor and focus at a distant point. This may
also be a good time to stretch, breathe deeply, and relax.
Cleaning Your Monitor and Glasses
Keep your display screen and your glasses or contact
lenses clean. If you use a glare-reduction filter, clean it
according to the manufacturer’s directions.
Having Your Eyes Examined
To be sure that your vision is adequately corrected, have
your eyes examined regularly by a vision care specialist. If
you wear bifocals, trifocals, or progressive addition lenses,
you may find that you need to assume an awkward
posture to use your glasses at the computer. Mention this
to your vision specialist and consider having glasses
prescribed that are specifically suited for working with a
computer monitor. For more information, refer to Chapter
3, in the section “Monitor.”
TIPS
Think about your
blink
While looking at your
monitor, remember
to blink. Although
blinking your eyes is
something you
normally do without
thinking, you may be
blinking less often
when using your
computer (studies
have indicated that,
on average, people
blink 1/3 as
frequently at the
computer). Blinking
helps keep your
eyes naturally
protected and
lubricated and helps
prevent dryness, a
common source of
discomfort.
Eye break
Give your eyes
frequent rests by
focusing them on a
distant point.

Safety & Comfort Guide 3–1
3
ARRANGING YOUR WORK AREA
Positioning Your Monitor
You may find a range of monitor heights that allows
your head to be balanced comfortably over your
shoulders.

3–2 Safety & Comfort Guide
Arranging Your Work Area
Monitor
You will reduce eye strain and muscle fatigue in your neck,
shoulders, and upper back by properly positioning your
monitor and adjusting its angle.
Positioning the Monitor
Place the monitor directly in front of you (refer to Chapter
3, in the section “Papers and Books”). To determine a
comfortable viewing distance, stretch your arm toward the
monitor and notice the location of your knuckles. Place
your monitor near that location. If needed, move the
monitor closer or farther away, until you can clearly and
comfortably see the displayed text (refer to Chapter 2, in
the section “Eyes”).
Adjusting the Monitor Height
Your monitor position should allow your head to be
balanced comfortably over your shoulders. It should not
cause your neck to bend forward uncomfortably or
backward to any degree. You may find it more
comfortable to position the monitor so that the top line of
text is just below your eye height. Your eyes should look
slightly downward when viewing the middle of the screen.
Many computer designs allow you to place the monitor on
top of the system unit. If this places the monitor too high,
you may want to move the the monitor to the desktop. On
the other hand, if the monitor sits on your work surface
and you feel any discomfort in your neck or upper back,
the monitor may be too low. In that case, try using a block,
book, or monitor stand to raise the monitor.
Tilting the Monitor
Tilt the monitor so that it faces your eyes. In general, the
monitor screen and your face should be parallel to each
other. To check for correct monitor tilt, have someone hold
a small mirror in the center of the viewing area. When
sitting in your normal work posture, you should be able to
see your eyes in the mirror.
TIP
Eye height
Your eye height will
change considerably
whether you use a
reclining or upright
posture, or some
posture in between.
Remember to adjust
your monitor’s height
and tilt each time
your eye height
changes as you
move through your
comfort zone.
Adjusting
brightness and
contrast
Reduce the potential
for eye discomfort by
using brightness and
contrast controls on
your monitor to
improve the quality
of text and graphics.
AVOID!
If you look at the
monitor more than
you look at paper
documents, avoid
placing your monitor
to the side.