Office Ergonomics Handbook
Fourth Edition
Your Workstation
What is Ergonomics?
Office Products
How Should I Sit at my Computer Workstation?
Your Chair
Your Chair
What makes a Chair Ergonomic?
How do I Adjust my Chair?
Your Workstation
Adjustable Desks
Adjusting a Non-Adjustable Working Surface
Your Overall Office
How Should I Hold my Telephone
Your Keyboard and Mouse
How do I Adjust My Keyboard and Mouse?
What About all Those “Ergonomic” Keyboards?
Keyboard Trays
Adjusting your Keyboard
Adjusting your Mouse
Wrist Rests
Setting up Your Keyboard and Mouse
Your Monitor
How do I Adjust my Monitor?
Adjusting Your Monitor
Monitor Arms
Document Holders
What Should I do About My Glasses?
Your Office Equipment
Your Office Lighting
What is Glare?
How Can I Reduce Glare?
Anti-Glare Screens
Muscle Recovery Are You Giving Your Body a Break
How should I Arrange My Office?
Short Term Fixes
Putting it all Together
What About Indoor Air Quality?
What About Thermal Comfort?
What Should I know About Electro Magnetic Fields?
What Precautions Should I take to Reduce EMF Exposure?
What is Noise?
How do I Reduce Annoying or Distracting Noise?
Stressed ???
How Does My Body React to Stress?
What are Some Sources of Stress in the Workplace?
Office Ergonomic Handbook
Your Workstation
What can be Done to Reduce Workplace Stress?
What Else can I do to Reduce Stress in my Life?
Putting it All Together
Appendix A: Legislation
Appendix B: Additional Resources/References
This handbook is intended to be a guideline only. If you have questions concerning the use of this
handbook please contact the Ergonomist at the Occupational Health Clinics for Ontario Workers nearest
Office Ergonomic Handbook
What is Ergonomics?
Ergonomics can be defined as fitting the job to the worker. All workers are not the
same size and everyone has limits. Ergonomics aims to design workstations, work
processes, equipment, and tools to fit you. As a worker, it is important that you know
how to adjust your office workstation to suit you.
If a job does not fit a worker, the worker is more likely to be exposed to risk factors that
may lead to musculoskeletal injury. The main ergonomic risk factors in the office include
the following:
repetition: tasks or body movements carried out over and over again.
awkward postures: body positions that are not considered neutral or "ideal" such as
twisting your neck to view your monitor or reaching forward or to the side to use your
static forces: maintaining a position for a long period of time (i.e. prolonged sitting,
viewing the monitor with a bent neck, or reaching for the keyboard).
Every person responds to ergonomic risk factors in different ways. For example, one
worker may have symptoms of an injury while another worker performing the same tasks
may not have symptoms. Ergonomic risk factors should be identified and reduced to
lower the risk of injury.
Office Products
When selecting office products, adjustability is the most important feature. Even though a
product claims to be "ergonomic" it may not suit your needs. Therefore, BUYER
BEWARE. You can use the information in this workbook to determine what equipment
you need to make your office fit you.
• Find out what you need
• Try Before You Buy - arrange to get some samples of equipment from different
• Make sure the supplier explains and demonstrates adjustment features to the
Office Ergonomic Handbook
How Should I Sit at My Computer Workstation?
"Preferred" sitting posture for computer work:
Naturally straight position; not bent up, down, or from side to side
Bent approximately between 90 and 100 degrees (right angle), close to
your body, and supported if possible
Relaxed (not slouched or raised)
Facing forward and not looking up, down, or to either side
Bent around 90 degrees with your thighs roughly parallel to the floor
Low back:
Supported to maintain its natural curve
Bent at approximately 90 degrees with enough space between the back of
your knees and the chair to place your fist. To test if correct, you should
be able to place your closed fist between the space.
Placed flat on the floor or supported by a footrest.
Many short breaks are better for the body than fewer, long breaks. These breaks, often
called "Micro-Breaks", last from 2 to 95 seconds and should be taken throughout the
day. During these Micro-Breaks, look away from the computer screen and focus on
objects in the distance, remove your hands from the keyboard and/or gently stretch
muscles. An example of an "active micro break” is taking 5-15 seconds every 5
minutes to rest the eyes and upper body.
Office Ergonomic Handbook
Your Workstation
Try to alternate your computer work with other tasks. For example, rather than typing
continuously for an hour, stop and deliver a fax or do some filing. When you break up
computer work with other office tasks, eyes and muscles in your arms, neck and back can
You may need to plan breaks into your day until you are used to taking breaks away from
the computer. Use the following table and worksheet as an example to help you organize
some well needed breaks.
8:00 to 8:30
Computer Work
8:30 to 9:00
9:00 to 9:30
Computer Work
9:30 to 9:35
9:35 to 10:00
Computer Work
Office Ergonomic Handbook
Your Chair
Your Chair
Your Chair
Your chair is the most important part of your office workstation. The
chair has to fit you and suit the tasks that you do. One chair may not suit
every worker so make sure you try it out before you buy. For example,
the “average” chair is designed in some instances to fit the average male
and may not suit some female users.
The chair is one of the most expensive pieces of office furniture. It is vital
that the chair be obtained initially on a trial basis, to test its suitability, with no obligation
to buy. If this is absolutely impossible, the purchase agreement should allow for the
return of the chair with a full refund. The trial period should be long enough to allow all
users an opportunity to try the chair and give their comments (i.e. several weeks).
What Makes a Chair “Ergonomic”?
The following features are part of a good office chair. A chair is only "ergonomic" if you
can adjust it to fit you. Get to know your chair by experimenting with the controls, so you
can make adjustments quickly and confidently.
• 5- caster swivel base
• Adjustments can be made easily while sitting in the chair
Seat pan
• Rounded front edge
• Wide enough and deep (long) enough to fit you comfortably
• Adjustable in angle
• Firm padding covered with non-slip, breathable fabric
When seat is too high, the front edge of the seat cuts into the back of the lower leg.
Source: Croney, J. 1980.
Office Ergonomic Handbook
Your Chair
• Curved to fit the shape of your back
• Padding for the low back area Height adjustable (separate from seat pan)
• Adjustable angle with locking mechanism
• Wide enough and high enough to fit your back comfortably while yo u work
Changes in the curvature of the spine when
Source: Grandjean, E. 1987
Example of lower back conforming to different
seat backs.
Source: McCormick, E.J., and Sanders, M.S. 1982
When we sit, our back adopts an unnatural posture, the lumbar support acts to maintain
the normal curvature of our spine when sitting.
• Allow chair to slide under work surface
• Ideally height and width adjustable
• Easily removed if in the way while you work
If armrests too high, they lift the individual out of the chair, or cause pressure at the shoulder joints.
Source: Croney, J. 1980.
Office Ergonomic Handbook
Your Chair
Recommended Chair Dimensions from the CSA Guideline on Office Ergonomics (CSAZ412)
Office Ergonomic Handbook
Your Chair
Office Ergonomic Handbook
Your Chair
How Do I Adjust My Chair?
How you adjust your chair depends on the other pieces of your workstation. You should
understand how to adjust your chair independent of the other work station components.
Chair adjustments should be made while sitting in your chair.
Raise or lower the chair until the edge of the seat pan is just below your kneecap
when you are standing (Figure 1).
Sit with your feet resting flat on the floor and your legs at a 90-110 degree angle
(Figure 2).
Allow enough space for a closed fist between the edge of the seat pan and the back of
your legs (Figure 2).
Adjust the backrest to support your lower back. You may need to move the backrest
up or down as well as towards or away from you (Figure 3).
Figure 1
Figure 2
Figure 3
Adjust the backrest so the low back support contacts the curve in your back and gives
you support in that area.
If your armrests are height adjustable, place them so your elbows can rest
comfortably on the rests, and your shoulders are level and relaxed.
Adjusting the chair height
If your keyboard is placed on a height and angle adjustable support.
• Lower the seat pan so your feet rest comfortably on the floor.
• Check for pressure points. You should feel even pressure from the seat pan. If you
feel more pressure near the back of the seat (buttock region), raise the chair. If you
feel more pressure under your thighs, near your knees, lower the chair.
If only your chair is adjustable.
• Adjust your chair height so you can type comfortably with "ideal" wrist and arm
• Use a footrest if your feet do not rest flat on the floor after you have adjusted your
Stand up and place your hand in the small of your back. Notice the inward curve in your
lower back. Sit down on your chair while keeping your hand on your lower back. Notice
how your curve flattens out. This shows you how easy it is to change the shape of your
spine which can contribute to back pain (refer to figure 3).
Office Ergonomic Handbook
Your Chair
Checklist of workstation dimensions from the CSA Guideline on Office Ergonomics
(CSA-Z412)Your workstation
Office Ergonomic Handbook
Your Workstation
Your Workstation
Adjustable Desks
It is often possible to add adjustable accessories to your desk. If you are purchasing a new
desk you may want one with adjustability included. There are several methods of
achieving adjustability.
You can purchase a complete workstation that allows for both regular desk work
and space for the computer. The computer section should have an adjustable
portion for the keyboard and mouse, and a separate adjustable portion for the
monitor. The portion of the desk designed for the keyboard should have enough
space for the mouse to be placed at its side.
You can add attachments to your desk such as keyboard and monitor trays.
You can use a smaller separate computer workstation and continue to use
your desk for regular work.
If you have shelves above the workstation, ensure they do not interfere with adjusting the
monitor height or block overhead lights.
Sit with your arms hanging straight at your side (Figure 4).
Adjust the writing surface to be level with your elbows (Figure 4)
Raise forearms to create approximately a 90-degree angle at the elbow (Figure 5).
Figure 4
Figure 5
Some workers prefer sit/stand stations since it allows them to change their
posture depending on the tasks they are performing.
Adjusting a Non-adjustable Working Surface
Sit with arms hanging straight at your side (Figure 4)
Raise your chair until the desk is level with your elbow.
Use a footrest to support your feet. Remember to keep a 90110 degree angle at the knee (Figure 6).
Raise your forearms to create approximately a 90-degree
angle at the elbow (Figure 5).
Office Ergonomic Handbook
Figure 6
Your Workstation
Note: If you need to raise your chair so you can write with your wrists straight and your
forearms almost parallel with the floor, your feet may not be able to touch the floor. If
your feet cannot rest comfortably on the floor, you will need a footrest.
• Raise the desk using a stable support such as blocks under the desk to
raise it (Figure 7).
• Raise the desk until the working surface or keyboard is at the level of
the elbow (Figure 7).
• Raise the forearm to create approximately a 90-degree angle at the
elbow (Figure 5).
• Purchase desks in the future that are height adjustable.
Figure 7
Your Overall Office
Before you set up your computer and other office equipment, you should think about the
information provided in all sections of this workbook.
How should I arrange everything on my desk?
The items on your desk should be arranged based on the number of times the item is used
(frequency of use) and the weight of the item. Heavy items, such as reference books,
should be placed within easy reach, even if they are not often used. The table below
categorizes items found on a typical desk based on frequency of use. The diagram below
shows the zone where these items should be placed.
Office Ergonomic Handbook
Tissue box
Reference books
In/out box
Your Workstation
How Should I Hold My Telephone?
If you have to write or type while talking on the phone, you
should use a headset or speakerphone to keep your hands free.
This will help to reduce awkward neck and shoulder positions.
The phone should be placed within close reach if used often
(50-60 cm).
Move your phone to the other side of your desk at your lunch break. Moving your
phone will remind you to pick up the phone receiver with both left and right hand.
Office Ergonomic Handbook
Your Computer
Your Computer
Your Computer
How Do I Adjust My Keyboard and Mouse?
Your keyboard and your mouse should be slightly below elbow level
and close to your body. The mouse should be right beside the
keyboard, and in front of your mousing hand. To use your keyboard
and your mouse in the "neutral" position, you should adjust your
keyboard or your chair.
If you have an adjustable keyboard/mouse tray:
• Move the keyboard and mouse to elbow level.
If you do not have an adjustable keyboard/mouse tray:
• Adjust the height of your chair so the keyboard and
mouse are at elbow level.
• The keyboard should be angled so your wrists remain naturally straight.
Get a co-worker to check your wrist posture as you type and help you make adjustments
if required. Read Appendix B on Arranging Your Keyboard and Monitor.
What About All Those "Ergonomic" Keyboards?
“Ergonomic” keyboards are designed to help you keep your wrists in a neutral (straight)
position when typing. It is important to first make as many improvements to your
workstation as possible before thinking of changing your keyboard.
Things to look into if you are thinking of changing your keyboard:
• The adjustability of the keyboard.
• How long it will take you to learn to type at your current typing speed.
• The force required to depress the keys.
• Some “ergonomic” keyboards are not adjustable and rely on a one-size- fits-all theory
however, this may not be appropriate for all users since people often have different
sized hands.
And remember the most important issue before you buy any office product:
"TRY BEFORE YOU BUY." And ensure that they comply with the CSA-Z412 Office
Ergonomics document.
Office Ergonomic Handbook
Your Computer
Keyboard Trays
Keyboard trays come in different sizes, adjustability levels and desk top connections.
The keyboard tray should:
Be big enough for both the keyboard and the mouse.
Be easily adjustable in both height and angle (in all
• Be free of attachments under the tray that can cause
bruising, scrapes or contact pressure with your thighs or
• Be easily moved under the desk and out of the way if
attached to your regular desk.
Allow enough space for a wrist rest if desired.
Adjusting Your Keyboard
Place the keyboard directly in front of you (Figure 5).
Type with your wrists “floating” over the keyboard (Figure 8).
Maintain a straight wrist position when you are typing (Figure
Figure 8
Adjusting Your Mouse
Place the mouse in front of your “mouse hand”. You should NOT
have to reach away from your body in order to operate the mouse
(Figure 9).
• Position the mouse at the SAME height as the keyboard.
Remember to maintain approximately a 90-degree elbow
Figure 9
• Maintain a straight wrist position when you are using the
mouse (Figure 10).
• Use your whole arm to move the mouse.
• If you are a dedicated mouse user try to work with your forearm supported. An Lshaped desk surface (Figure 9) or an armrest can be used to
support your forearm.
Figure 10
Mouse Pads
A mouse pad should be used, in order to keep the mouse clean and moving easily.
Office Ergonomic Handbook
Your Computer
Mouse Tips
To reduce stress on the hand you use most often, try to use the
mouse with the opposite hand provided you are using a universal
mouse and not one that has been contoured to a specific hand. This reduces the stress
placed on one arm and frees the dominant hand to perform other tasks. Try moving your
arm and shoulder rather than only your hand when mousing.
When using the mouse for long periods of time, your lower
arms should be supported. To support your arms:
• Rest your mousing arm on one side of the desk if your
desk is "L" shaped and the height is around elbow level.
• Rest your elbows on your armrests. Make sure the
armrests do not restrict your arm movement when
There are also other forms of inputting devices that can be used for actions similar to
a mouse on the market, it is recommended that you first try before you buy.
Wrist Rests (Keyboard and Mouse)
Padded wrist rests are often used in front of keyboards and mice to support your wrists.
Wrist rests also reduce the contact pressure on your wrists from sharp work station edges
when you are taking a break from typing. However, these rests can also inc rease the
pressure on your wrists, thus increasing the risk of injury, especially if used while typing.
Typing should be performed with the hands "floating" above the keyboard. The wrists
should only be resting on the wrist pads when pausing. Touch typing may also
improve your neck posture by reducing the number of times you have to look down at
your fingers on the keyboard.
Wrist rests used when taking a typing break should:
• Be long enough to be in front of the entire keyboard and possibly the mouse.
• Be high enough to keep your wrist in a straight neutral position. Slightly bent
back is okay!
• Be made of moderately firm material.
Resting surfaces should be flat with curved edges on the front and back edges to avoid
pinch points.
Office Ergonomic Handbook
Your Computer
Setting up Your Keyboard and Mouse
To keep wrists, elbows and shoulders in the “preferred
position” for computer work.
What is the position of your elbows and wrist when you are
typing and/or using the mouse? If it is similar to the one shown above, you should be able
to work in a comfortable position.
Do the height of your keyboard and mouse allow for the "ideal" wrist and elbow
posture? If not, compare your set up with the pictures below.
Are your hands below
your elbows when typing?
If yes, try raising your
Are your hands above your
elbows when typing? If yes,
try lowering your keyboard
or raising your chair.
You should adjust your workstation so your hands are at elbow height, or slightly lower
than elbow height, when using the keyboard or mouse. When a keyboard sits on the desk
it is usually too high. You may need a keyboard tray to lower the keyboard.
Your keyboard angle should not force your wrists to bend forward (flex) or
backward (extend).
The angle of the keyboard/mouse tray should allow your wrists to stay in a
straight posture.
When the keyboard feet at the back of the keyboard (towards monitor) are
elevated, the wrists may bend backward (extend) when typing.
In contrast, if a wrist rest is used and is too high, the wrists tend to bend forward
when typing.
Office Ergonomic Handbook
Your Computer
What is the angle of your keyboard?
Does it allow your wrists to be straight when typing?
The Natural, Straight Line – CORRECT
Arching-Wrist Position – INCORRECT
What is the position of your mouse? If it is similar to the picture shown below (close to
the keyboard-picture A) you should be able to keep your arms close to your body in a
comfortable position. If not, compare your set up with the pictures below.
Do you have to reach to use your mouse?
If yes, put your mouse directly beside your keyboard or support your lower arm while
using the mouse.
Office Ergonomic Handbook
Your Monitor
Your Monitor
How Do I Adjust My Monitor?
The monitor and keyboard should be directly in front of you.
The top of the monitor and document holder should be around eye level when you are
sitting comfortably.
The monitor should be about arm's length away from you at a comfortable reading
The monitor should be angled slightly up toward your eyes. Angling the monitor up
too high can increase glare (see the lighting section).
Since your eyesight naturally falls about 20 degrees down
from the horizontal, the top of the screen should be placed
around eye level. You should not have to bend your neck
forward or backward to view the screen in this position. Your
line of sight should naturally fall to the middle of the screen.
It is often much easier to raise the monitor than to lower it. If
the monitor cannot be lowered enough, so your neck is
straight when looking at the screen, you may have to raise your chair. If your chair is
raised, the keyboard height may have to be re-adjusted along with your footrest height if
you use a footrest.
Desks often do not have enough space to move the monitor at arm's length distance from
your eyes. If this is the case, other changes may be needed such as keyboard trays and rearranging furniture.
Adjusting Your Monitor
Adjust the monitor height until the top of the monitor is at or just slightly below eye
level (Figure 11).
Position the monitor approximately one arm’s length away from you when you are
sitting (Figure 11).
To keep your neck in the “preferred” position for
computer work.
To keep your eyes in their natural line of vision.
Figure 11
Office Ergonomic Handbook
When the monitor sits on top of the hard drive, it is usually
too high. Monitors are usually too low when they sit on
the desk. Check the height of your monitor.
Your Monitor
Documents placed flat on the desk require your neck to bend forward while reading. A
document holder will enable you to work with your head upright.
What is the placement of your monitor and documents? If they are similar to those
shown in the above picture, you should be able to type with your head upright and your
eyes in their natural line of vision. If your monitor and document arrangement is not
similar to the one shown above, compare your set up to the following three work stations.
Is your neck bent back,
even slightly, when
viewing the screen
and/or document(s)? If
yes, try lowering your
monitor and/or
Is your neck bent
forward when viewing
the screen and/or
document(s)? If yes, try
raising the monitor
and/or documents.
Is your neck twisted to either side when
viewing the screen?
If yes, try placing the monitor directly in front
of you.
Office Ergonomic Handbook
Your Monitor
Monitor Arms
Monitor arms should allow the monitor to move in all directions and allow you to push
the monitor completely out of the way when not in use. When buying monitor stands or
arms ensure that:
The monitor can be located at the proper height. Movable
arms may not go low enough for some operators.
The stand is not too high. Computer hard drives are often used
to raise the monitor but this often forces the operator to look up
to see the monitor.
The arm must be strong enough to support the weight of the
Document Holders
You should use a document holder if you enter information from papers. Document
holders help keep papers vertical or angled so you do not have to bend your neck to read
them, as you do when papers are flat on the desk.
The document holder should be the same distance from your eyes as the computer screen.
When the document is close to the monitor, it is easier for your eves to refocus between
the paper and screen. By refocusing less, strain on muscles in the eyes is reduced.
Various types of document holders are available including the
• Those that sit on desks;
• Those that can be attached to the side of the monitor;
• Those that are on a movable arm which attach to or sit
on the work surface. If you choose a document holder
that sits on the desk, ensure there is enough space beside
your monitor.
When buying document holder ensure the holder has the
following features:
• Large enough for the different sizes and types of papers,
books, files and documents you use.
• Strong enough to hold the weight of items that are used
frequently such as books, binders and thick documents.
• Easily adjustable (forward, backwards and sideways) to
accommodate differences in print sizes and copy quality.
• The mechanism to hold the paper must be firm enough to
prevent the paper from slipping out of the holder, adaptable to
various sized documents, and easy to operate.
• The paper should remain straight (not curl up) and be easy to read.
• Easily moved to either side of the monitor.
Note: If you cannot find a suitable document holder, you could attempt to design your
own! Be creative!
Office Ergonomic Handbook
Your Monitor
What Should I Do About My Glasses?
Vision problems can lead to eye strain and headaches. If you work in an
office, you should have regular eye examinations to correct vision
problems. You should explain the work you do with computers to your
eye doctor. If you wear bifocals, you may have trouble when working
on computers since the lenses are generally designed for reading at a
viewing distance of 40 to 50 cm and a downward gaze of about 25
degrees. The monitor should be lower and closer to a person who wears
bifocal glasses depending on which portion of the glasses is used to read the monitor. If
work station design changes do not correct bifocal glasses problems, special computer
glasses can be purchased.
Your ophthalmologist or optometrist will gain a better understanding about your office
with a sketch or photograph. Mark the distance from your eyes to the monitor,
documents, and the keyboard on the sketch.
Cables are usually available in varying lengths so you can position your monitor
wherever necessary.
Some hard drives or central processing units (CPUs) can be placed on their side.
Check with your computer technician before turning your hard drive on its side.
You may need a co-worker to watch you to determine if you are working in an
awkward position. It is often difficult to tell if your neck is slightly bent. Even if
your neck is only slightly bent back, your neck and shoulder muscles may ache
and tire faster than when in an "ideal" position.
Your monitor and document holder should be at eye level or slightly lower than
eye level. When sitting comfortably in your chair, your eyes should fall naturally
on the middle of the screen without having to bend your neck forward or
Bifocal wearers have special needs. Those who look through the bottom part of
their glasses tend to look up at a screen that is around eye level. If your neck is
bent back, try lowering your monitor further. The monitor should be lower and
slightly angled up towards your eyes. When the monitor is angled up, it may be
affected by glare from overhead lights. An anti- glare screen can be used to reduce
Office Ergonomic Handbook
Your Monitor
Checklist of workstation dimensions from the CSA Guideline on Office Ergonomics
Office Ergonomic Handbook
Your Monitor
The use of laptops is increasing as prices decrease. Originally designed for easy transport
and short-term use, the portability of laptops is a popular feature. Since many people
now travel as part of their job, the laptop is starting to replace the traditional computer in
some offices. There are a variety of problems that can arise from prolonged laptop use:
The worker may place the laptop at an angle which is comfortable for the hands and
arms, but can result in neck fatigue from bending to view the screen.
Conversely, the worker may raise the laptop to view the screen, thereby placing the
hands and arms in awkward postures.
The small screen size can result in difficulty with reading and can lead to bending of
the neck and upper back.
Small key spacing results in cramped and awkward postures of the hands, arms, and
Worker can experience awkward postures of the wrist when manipulating the
trackball or guiding device.
Angling of the monitor to compensate for low height of the laptop can result in
increased glare upon the screen.
• Use a computer docking station when in the office. This normally consists of a full
size monitor, keyboard, and mouse with the laptop basically serving as the hard drive.
• When on the road, pack a light-weight keyboard and mouse
Office Ergonomic Handbook
Your Office Environment
Your Office Environment
Your Office Lighting
Lighting is important in offices where computers are used.
The amount of light affects eye strain and postures. Light
levels must be high enough for paper work, but not too bright
for computer work. If light levels are too low for paper work,
muscles of the eyes are strained and you are more likely to
work in an awkward posture to see the paper. When light
levels are too high for computer work, you may be forced
into an awkward posture in order to see the screen.
Since computer and paper work are performed at the same time in most offices, light
levels must suit both types of work. It is preferred if light levels can be controlled by a
dimmer switch. A desk lamp, is also useful because you can turn it on for paper work and
off for computer work. You can also redirect a desk la mp when working on the computer.
What is Glare ?
Glare is a common problem with lighting in offices. It makes it
difficult to see the computer screen and strains the eyes. In
order to see the screen when there is glare, you may move into
awkward postures.
There are two forms of glare: direct and indirect.
Direct glare occurs when light shines directly in your eyes. If an
overhead light is in front of the computer monitor in your field
of view, it may cause direct glare.
Indirect glare occurs when light is reflected from a surface.
For example, sunlight from the window behind your desk
may hit the monitor and reflect into your eyes.
To find out if your computer work station is affected by glare, turn the monitor off and
look at the screen in a mirror. Any objects or lights reflected back into the mirror are
sources of glare. Even bright clothes at work can cause glare on the monitor.
Office Ergonomic Handbook
Your Office Environment
How Can I Reduce Glare?
Locate your monitor parallel to the windows and in between overhead light panels.
• Use curtains and blinds to control the amount of natural light entering your office.
• Eliminate light sources that shine directly into your eyes.
• Eliminate light sources that reflect into your eyes.
• Control light sources that shine directly above your computer monitor. Lights directly
above a monitor can create glare.
• Dim overhead lights.
• Locate your workstation beside windows and overhead lights, not in front, behind, or
directly below them.
• Angle the monitor away from the light.
• Use dark curtains or blinds to cover windows or skylights.
• Place filters or fixtures on overhead lights.
• Cover the monitor with an anti-glare screen.
Office Ergonomic Handbook
Your Office Environment
Sit in your chair as you do while working. Notice where the lights are positioned. If there
are lights or windows directly in front of or behind your computer, think of ways you
could move your desk and computer to reduce glare. Keep in mind your goal is to sit
beside lights and windows, rather than in front of or behind them. Get help to move your
desk and computer, so lights and windows are beside you.
Anti-Glare Screens
Anti- glare screens can be used to reduce the glare on your computer screen. These
screens are available in varying styles.
The most common anti-glare screens are made of mesh or glass. Polarized glass provides
the best protection, as well as the most comfort, when viewing the screen. Mesh screens
are available but they tend to distort the words and are more difficult to clean. Therefore,
glass anti-glare screens are preferable. Once a glare screen is purchased, it is important to
clean it regularly to remove dust that may blur the screen.
Office Ergonomic Handbook
Your Office Environment
Muscle Recovery
Are You Giving Your Body a Break?
It is important to stand up and get away from your desk and/or computer regularly
throughout the day even if your work station is designed to suit your body. A five minute
break away from the computer every hour allows your eyes, neck, back, shoulders, and
arms to rest.
The previous description of the "ideal" sitting position is
provided only as a general guideline because the muscles work
best when the body joints are in "neutral" positions. However,
you should not remain in any one position (seated or
otherwise) for long periods of time. Changing positions
throughout the day will help to reduce the stress and strain that
builds up from staying in one position for a long time. For
example, adjusting the angle of the back rest of your chair even slightly will help change
the position of your spine, giving certain muscles a "break”.
Movement is also necessary to reduce the stress that builds up from sitting. Getting up
and walking around, even short distances, throughout the day helps to
reduce stress by improving circulation in the muscles and the spine.
If your computer workstation can be adjusted, one option is to stand
while working at your computer. Even if your work station is not fully
adjustable, tasks like talking on the phone, can be done while
standing. It is preferable to break up sitting and standing tasks throughout the day.
Other daily tasks, such as filing and delivering, can be done when you take a break away
from your computer. Avoid remaining seated for extended periods of time. Try to stand
up and change your position every hour.
Office Ergonomic Handbook
Your Office Environment
How Should I Arrange Everything in My Office?
Printers, faxes etc. should not obstruct movement.
Adequate space should be available for maintenance on any
piece of equipment.
You should use filing cabinets with a locking system so that
no more than one drawer can be opened at once. If more than
one drawer is opened there is a risk of the cabinet tipping.
Files and books that are used most often should be kept within
easy reach.
Files should be arranged in a filing cabinet so frequently used
files are in the middle drawer or closest to elbow level. This
should reduce the amount of bending and reaching required.
Filing cabinets should be located so you have to stand up from
your chair and walk to them. If the cabinet is far enough away
you may have to stand to reach it. You will be less likely to twist and reach which
may result in injury.
There should be enough space between the cabinet and the wall to pull open the
drawers (approx. 107 cm for vertical files and 81 cm for lateral files).
File and desk drawers should be kept closed when not in use to avoid trips, bumps
and scrapes.
Frequently used books or binders should be within easy reach when you are sitting at
your desk. This is very important, especially if these books are often used while you
talk on the phone.
Heavy books should be obtained while standing and placed on the middle shelf or
around elbow level.
Shelf depth should allow for a comfortable reach.
Short Term Fixes
If any of the above products are not available, experiment with the following:
Wrist rests can be made from pieces of foam or rolled up towels.
A stable surface such as text books, a pad of photocopy paper or monitor trays can
be placed under monitors in order to adjust the height. They can also be used as
File folders make good document holders when placed between the function keys
of the keyboard and the front of the monitor. One to two sheets of paper can rest
on the folder when being viewed.
Documents can be taped to the side of the monitor when typing from only one
Clip boards can be used as document holders and work best if they can be placed
between the keyboard and the monitor.
Office Ergonomic Handbook
Your Office Environment
Various boxes can be used as footrests. For example, an empty orange crate can be turned
upside down. If you are creative, it can even be padded for a more comfortable rest.
Makeshift footrests may not last as long as those commercially produced but they may be
more accessible.
Cables are available so you can move computer components and telephones.
Office Ergonomic Handbook
Putting It All Together
Putting it all Together
Office Environmental Concerns
Other office environmental concerns include indoor air quality, thermal comfort,
electromagnetic fields, and noise.
What About Indoor Air Quality?
Poor indoor air quality can cause many health problems. Common concerns in the office
environment associated with poor indoor air quality can include:
• Eye, nose and throat irritations
• Headache
• Dry mucous membranes
• Dry skin
• Mental fatigue, trouble concentrating
• Nausea and dizziness
• Increased incidence of respir atory infections
When would I suspect that Indoor Air Quality may be a problem in my workplace?
• Many of your co-workers have had most of the symptoms listed above on a weekly
• The building ventilation system is deficient
• The building has musty or chemical odours and/or has a history of water leaks.
Symptoms similar to those associated with poor indoor air quality can also be related to
the following:
• Poor ergonomic design of workstations,
• Problems with lighting and noise,
• Occupational or organizational stress.
Ways to avoid indoor air quality issues:
Regular maintenance of the ventilation system and regular duct cleaning
Providing air purifiers in different areas of the office
Identifying possible sources of mold, i.e. wet spots on ceiling tiles
Office Ergonomic Handbook
Putting it all Together
What About Thermal Comfort?
Do you feel hot, cold, or both? Is your skin dry? Is there a draft
that makes you feel cold? If you answered yes to these questions,
there may be temperature, humidity, and/or draft problems in
your workplace. Thermal comfort is affected by your heating,
ventilation and air conditioning (HVAC) system, the work
activities you are doing, and personal preference.
The recommended temperature range is 20 to 23.5 C in the winter
and 23 to 26 degrees C in the summer with a relative humidity
between 30% and 60%. The temperature range is lower in the
winter because people tend to dress in warmer clothes.
Feeling cold can lead to increased muscle tension, increased stress levels, and awkward
working postures, such as hunched shoulders.
What can be done about thermal comfort in my work place?
Discuss the following issues with your Joint Health and Safety Committee:
Varying temperatures throughout the office
Static shocks
Possible Causes
Vents may not be positioned properly
HVAC system may not be working
Humidity level may be too low
Agree on one temperature setting at your work place. Workers can then dress
according to their personal preference.
If temperatures vary or you do not have control over the temperature, dress in layers.
As a temporary solution, investigate the use of heaters or fans to accommodate
personal preferences.
What can I do if I have concerns about indoor air quality or thermal comfort in my
If you are concerned about indoor air quality or thermal comfort, talk to your Joint Health
and Safety Committee members or contact an Occupational Health Clinics for Ontario
Workers Inc. (OHCOW )Occupational Hygienist at the Clinic nearest to you.
Office Ergonomic Handbook
Putting it all Together
What Should I Know About Electromagnetic Fields?
Electromagnetic fields (EMFs) are invisible lines of force that
occur wherever there is electricity. They are made up of
electric and magnetic fields. Electric fields can be blocked, but
you cannot block magnetic fields. There is no conclusive
evidence that EMF emissions from a computer cause negative
health effects.
What are some sources of EMFs?
Some other sources of electromagnetic fields in the office are:
• Ceiling fluorescent lights
• Photocopy machines
• Wiring
• Computers
Another problem associated with computer workstations is electrostatic emissions, or
static fields. Static fields attract dust to the computer screen. Some skin problems that
have occurred in computer users may be due to the attraction of electrically charged dust
particles to the skin.
To help control static, use a grounded glare screen or keyboard pad. Anti-static acrylic or
plastic chair mats are also available.
What Precautions Should I Take to Reduce EMF Exposure?
Sit at least arm’s length 71cm (28 inches) away from the computer monitor, and
approximately 4 feet from the backs and sides of co-workers' monitors.
Electromagnetic emissions are reduced with distance; magnetic fields are not blocked
by baffles or walls.
Avoid sitting next to electrical equipment (fax machines, laser printers, photocopiers).
Take regular breaks away from computer work. This will reduce the exposure time to
the electromagnetic fields.
Radiation-reducing glare screens (or shields) may reduce the electric component of
the electromagnetic fields. Do not use a shield that distorts the clarity of print on the
Turn off the computer when not in use.
Use equipment manufactured after 1983. Regulations were issued requiring that the
radio frequency radiation from all computers be shielded to minimize interference
with radio transmissions. Equipment manufactured prior to 1970 should never be
used because it may emit X-ray radiation.
Turn your radio to an AM frequency so you hear static. Put the radio close to your
monitor and move it away slowly. Notice how the noise decreases as you move away
from the monitor. The EMFs drop off as you move away from the monitor and interfere
less with the AM frequency.
Office Ergonomic Handbook
Putting it all Together
What is Noise?
Noise is any unpleasant sound. We tend to call it "sound" when it is not
annoying and "noise" when it is! Noise levels in your office are probably
not high enough to damage your hearing, but noise ma y still cause
Noise may:
• Interfere with communication.
• Annoy or distract people nearby.
• Increase the level of concentration required and in turn, increase the level of fatigue.
• Cause stress.
Where Does Noise Come From in My Office
Some sources of noise in an office environment are co-workers, the
ventilation systems, fans, computers, photocopiers, fax machines,
telephones, and the everyday outdoor noises, such as traffic.
How Do I Reduce Annoying or Distracting Noise?
Noise reduction is a specialized field in itself, but there are a number of techniques that
may be used to reduce noise.
Sound-absorbing tile, carpet, and barrier walls can be used.
Noisy equipment can be isolated. For example, place the photocopy machine
in a separate room to reduce noise.
Use ear plugs as a temporary solution while investigating noise reduction
Follow a regular maintenance schedule for the office equipment.
Office Ergonomic Handbook
Putting it all Together
Is your head pounding? Stomach upset? Feeling cold and
clammy? You may be experiencing stress.
Stress is a serious workplace problem. You may experience
stress as you drive through traffic to get to work, when you look
at your "to do" list, or after your boss asks you to finish typing a
letter which must be faxed immediately. It is no wonder you
may be feeling tired by the end of the work day.
How Does My Body React to Stress?
Upset stomach.
Increased heart rate and blood pressure.
Cold, clammy hands.
Increased muscle tension.
Rapid and shallow breathing.
To feel physical stress, make a fist with your right hand. Squeeze tightly for several
seconds. Notice the tension in yo ur hand, wrist and arm. To feel relaxation, open your
hand gradually and pay attention to how light it feels in comparison to when you made a
fist. This exercise can be performed with all muscle groups. Stress at work can play an
important role in injury development. Stress can cause increased tightness in the shoulder
and neck muscles and increase the risk of injury. Therefore, a reduction in stress may
reduce the risk of injury.
What are some sources of stress in the workplace?
Stress levels at work can be affected by the following:
• A lack of job security
• A lack of control over how you do your job
• Having too much or too little to do
• Monotonous, repetitive work
• Not knowing what is expected of you
• Conflicting expectations or task demands
• Not being able to predict what people expect from you
• A lack of help, cooperation, and support from co-workers
• A lack of conversational privacy, distractions from noise
CSA-Z412 states:
“Poorly designed working conditions therefore place a stress load on workers both
physically and psychologically. When people feel stresses, they often carry extra tension in
their muscles. They may use excessive force to accomplish a task, or move in a jerky
fashion rather than in a smooth, controlled fashion. This can exacerbate the physical job
demands and contribute to work-related musculoskeletal disorders.”
Office Ergonomic Handbook
Putting it all Together
What Can Be Done to Reduce Workplace Stress?
There are several things that can be done within your office environment to help reduce
stress. Some examples are as follows:
• Good communication, including regular
staff meetings, is the key to reducing stress
in the work place.
• Control over everyday activities.
• There should be an open-door policy so
workers can freely talk to supervisors about
tasks to be performed and job expectations.
• If there are threats to job security, workers
should be informed as soon as information
about the future is known.
• Roles and responsibilities should be dearly defined when tasks
are assigned.
• Every effort should be made to create a socially supportive work
place where all workers feel they are an important part of the
• Workers should be given a chance to use and develop their skills.
• Reduce monotony through job enlargement and/or enhancement.
What Else Can I Do to Reduce Stress in My Life?
Some other things you can do to reduce stress include regular breaks, breathing and
stretching exercises, and living a healthy life style.
Living a healthy lifestyle strengthens your body. Along
with regular exercise, a healthy lifestyle includes the
• Not smoking or being exposed to smoke
• Eating a balanced diet from the Canada Food Guide
• Getting enough rest and relaxation
Stretching can give your body a break and reduce stress.
For stretching exercises that suit your needs, talk to a health professional.
When you feel stress, your breathing becomes rapid and shallow. By concentrating on
deep breathing, you can reduce your stress level.
Sit or stand comfortably with your hands on your stomach. Breathe in through your nose
slowly and deeply. Once you have inhaled as much as you can, hold your breath for a few
seconds before breathing out. Exhale slowly through your mouth with your lips
positioned as if you were going to whistle. When you are finished exhaling, breath in
again slowly and repeat the cycle until you start to feel better.
Office Ergonomic Handbook
Putting it all Together
Putting it all Together
In order to be comfortable at your computer workstation the following steps should be
used to ensure the workstation fits your needs. If you feel fatigued or start to experience
muscle pain use this checklist to re-evaluate your workstation. Do not be afraid to adjust
your workstation. Remember, prevention is the best cure for musculoskeletal injuries!
Adjusting Your Chair
Raise or lower the chair until the edge of the
seat pan is just below your knee cap when you
are standing (Figure 12).
Sit with your feet resting flat on the floor and your legs at a
90-110 degree angle (Figure 13).
Allow enough space for a closed fist between
the edge of the seat pan and the back of your legs
(Figure 13).
Figure 12
Adjust the backrest to support your lower back.
You may need to move the backrest up or down
as well as towards you, or away from you
Figure 14
Adjusting and Adjustable Working Surface
Sit with your arms hanging straight at your side
(Figure 15).
Adjust the desk or keyboard tray to be level with
your elbows (Figure 15).
Figure 15
Raise your forearms to create a 90 degree angle
at the elbow (Figure 16).
Figure 16
Office Ergonomic Handbook
Putting it all Together
A: The working surface is too high
Sit with your arms hanging straight at your side
(Figure 15).
Raise your chair until the desk or keyboard tray
is level with your elbow.
Use a footrest to support your feet. Remember to
keep a 90-110 degree angle at the knee (Figure 17).
Figure 17
Raise your forearms to create a 90 degree angle
at the elbow (Figure 16).
B: The working surface is too low
Place blocks under the desk to raise it (Figure 18).
Raise the desk until the working surface or keyboard
is at the level of the elbow (Figure 18).
Figure 18
Raise the forearm to create a 90 degree angle at the
elbow (Figure 16).
Adjusting Your Keyboard
Place the keyboard directly in front of you
(Figure 16).
Figure 19
Type with your wrists “floating” over the keyboard
(Figure 18).
Maintain a straight wrist position when you are typing (Figure 16).
Adjusting Your Mouse
Place the mouse in front of your “mouse hand”
You should NOT have to reach away from your
body in order to operate the mouse (Figure 20).
Figure 20
Position the mouse at the SAME height as the
keyboard. Remember to maintain a 90 degree
elbow angle.
Office Ergonomic Handbook
Putting it all Together
Maintain a straight wrist position when you are
using the mouse (Figure 21).
Use your whole arm to move the mouse.
If you are a dedicated mouse user try to work with your
forearm supported. An L-shaped desk surface (Figure 20)
or an armrest can be used.
Figure 21
Adjusting Your Monitor
Adjust the monitor height until the top of the
monitor is at or just slightly below eye level
(Figure 22).
Position the monitor approximately one arm’s
length away from you when you are sitting
(Figure 22).
Figure 22
Adjusting Your Document Holder
Place the document holder at the same level
as the monitor (Figure 23).
Place the document holder the same distance away from
you as the monitor (Figure 23).
Figure 23
Locate your monitor parallel to the windows
and in between overhead light panels (Figure24).
Use curtains and blinds to control the amount of
natural light entering your office.
Eliminate light sources which shine directly into
your eyes (Figure 25).
Eliminate light sources which reflect into your
eyes (Figure 25).
Control light sources which shine directly above
your computer monitor. Light directly above a
monitor can create glare (Figure 25).
Office Ergonomic Handbook
Figure 24
Figure 254
Putting it all Together
Install sound absorbing materials when possible.
(carpets, acoustical tiles, office dividers, rubber pads
under printers)
Locate photocopiers, fax machines and other noisy
office equipment in a separate room.
Follow a regular maintenance schedule for the office
Now that you have completed the workbook, you should be able to adjust your
workstation to suit you. It will take some effort for the principles from this workbook to
become a part of your everyday life. Refer back to this workbook periodically to refresh
your knowledge about office ergonomics.
Ergonomic equipment is only ergonomic if used correctly. Learn how to use your
Reduce repetitive movements, awkward postures and static forces. Be conscious of
your body positions and movements!
Take a break away from your computer at least once every hour. Remember to keep
All aspects of your office interact to affect your health (workstation design, stress, air
quality noise, etc.). Keep the communication lines open!
Office Ergonomic Handbook
Appendix A:
Appendix B:
Appendix A - Legislation
As a worker in Ontario, you may be covered by the Occupational Health and Safety Act
(provincial) or the Canada Labour Code (federal). Members of your Joint Health and
Safety Committee should know which legislation applies to you.
Under the Occupational Health and Safety Act and the Canada Labour Code, workers
have three basic rights:
The right to know about workplace health and safety hazards
The right to participate in making recommendations about health and safety concerns
The right to refuse work if they have reason to believe it endangers their health and
These rights can be used to protect office workers.
In Ontario while the only specific regulations that apply to ergonomics concern health
care workers, they may be of use to you as a guide. Specifically, Health Care and
Residential Facilities (Ontario Regulation 67/93) reads:
If a worker is required to use a video display terminal for a continuous period of
one hour or more, the worker shall have at least five minutes of time free from
such work in every hour.
Sections 22 through 27 deal with lighting and read in part:
If a glare from a direct lighting source is likely to be a
hazard to a worker, the source shall be shielded by louvres,
lenses, lens covers or diffusers which control the glare.
Lighting is also discussed in Section 6 of the Canada Occupational Safety and Health
Regulations. Some of the highlights are as follows:
Section 6.7(2)
Reflection glare on a VDT screen shall be reduced to the point where an employee at a
task position is able to
(a) read every portion of any text displayed on the screen and
(b) (b) see every portion of the visual display on the screen.
Section 6.7(3)
Where VDT work requires the reading of a document, supplementary lighting shall be
provided where necessary to give a level of lighting of at least 500 lux on the document.
Office Ergonomic Handbook
Appendix A - Legislation
Recently the federal government's Treasury Board has passed a series of policy, which
provide specific guidelines for office workers. These guidelines can be found on the
Treasury Board website They may be helpful to you when trying to
assess your needs and develop language for your own collective agreement.
British Columbia and Saskatchewan are the only provinces which has passed Ergonomic
Section 4.46 of BC regulations stated defines ergonomics as:
"musculoskeletal injury" or "MSI" means an injury or disorder of the muscles,
tendons, ligaments, joints, nerves, blood vessels or related soft tissue including a
sprain, strain and inflammation, that may be caused or aggravated by work.
The full text of the regulations, which includes risk factors and safety requirements may
be found on the B.C. W.C.B. website.
Office Ergonomic Handbook
Appendix B – Additional Resources/References
Guideline on Office Ergonomics
Canadian Standards Association
178 Rexdale Boulevard
Toronto, Ontario
M9W 1R3
Tel: (416) 747-4000 /1 800 463-6727
Fax: (416) 747-4149
Croney, J. Anthropometry for Designers. Tiptree, Essex. Anchor Press. 1980.
Grandjean, E. (1987). Ergonomics in Computerized Offices. Taylor & Francis:London.
Grandjean, E. Design of VDT Workstations. In: Handbook of Human Factors. Edited
by G. Salvendy. New York. Wiley and Sons. 1987.
ISO 6385,
Ergonomic Principles in the Design of
Work Systems
Standards Council of Canada
270 Albert Street, Suite 200
K1P 6N7
Tel.: (613) 238-3222
Fax: (613) 569-7808
Ministry of Labour (1995). VDT Workstations: Layout and Lighting. Ministry of Labour:
Toronto. MOL Publications tel. 1-800-268-8013
Workers' Compensation Board of B.C. (1994). Draft Ergonomics Regulations. WCB of
BC: Richmond. WCB tel. (604) 279-7586.
Some of the Diagrams are reproduced with the permission of the Canadian Standards
Association from CSA-Z412-00. While the use of this material has been authorized, CSA
shall not be held responsible for the manner in which the material is represented nor for
any interpretations thereof.
Office Ergonomic Handbook
If you need further assistance, call the Occupational
Health Clinics for Ontario Workers Inc. closest to you.
Provincial Office
15 Gervais Dr.
Don Mills On
M3C 1Y8
1-877-817-0336 (toll free)
970 Lawrence Ave, West
Main Floor
Toronto On
M6A 3B6
416-449-7772 (fax)
1-800-461-7120 (toll free)
3129 Marentette Ave.,
Unit 1
Windsor On
N8X 4G1
519-973-1906 (fax)
1-800-565-3185 (toll free)
848 Main Street, East
Hamilton On
L8M 1L9
905-549-7993 (fax)
1-800-263-2129 (toll free)
171 Kendall Street
Point Edward On
N7V 4G6
519-337-9442 (fax)
1300 Paris St. Unit 4
Sudbury On
P3E 3A3
705-523-2606 (fax)
1-800-461-7120 (toll free)
3-380 Adelaide St. North
London On
N6B 3P6
519-642-7834 (fax)
Every effort has been made to ensure the accuracy of the information in this workbook.
OHCOW assumes no responsibility for how this information is used.
Office Ergonomic Handbook
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