Office Ergonomics Manual

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Office Ergonomics Manual

Concordia University

Collaborators: Christine Durant, Lina Filacchione, Rosa Gullo

Revised August, 2006

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CONTENTS 1 INTRODUCTION .............................................................................................................4 2 SETTING UP YOUR WORKSTATION............................................................................5

2.1 CHAIR ........................................................................................................................5 2.2 MONITOR ...................................................................................................................7 2.3 KEYBOARD AND MOUSE ..............................................................................................9 2.4 LAYOUT/DESK/EQUIPMENT AND ACCESSORIES ...........................................................11 2.5 LIGHTING .................................................................................................................13 2.6 ENVIRONMENTAL CONTROLS .....................................................................................14

3 USE OF LAPTOPS AND PERSONAL DIGITAL ASSISTANTS (PDAS)......................14 3.1 LAPTOPS..................................................................................................................14

3.1.1 Laptop Accessories.............................................................................................14 3.1.2 Laptop design features associated with musculoskeletal symptoms ..................15 3.1.3 Laptop Tips .........................................................................................................15 3.1.4 Transporting Laptop............................................................................................16

3.2 PDAS ......................................................................................................................16 3.2.1 Tips and recommendations for PDA use.............................................................16 3.2.2 PDA Product Add-Ons ........................................................................................17

4 ERGONOMIC HEALTH ISSUES...................................................................................17 4.1 CUMULATIVE TRAUMA DISORDERS (CTDS) ................................................................17

4.1.1 CTD Symptoms...................................................................................................17 4.1.2 Prevention...........................................................................................................18

4.2 COMMON AILMENTS/DISORDERS................................................................................18 4.2.1 Carpal Tunnel Syndrome ....................................................................................19 4.2.2 Stress..................................................................................................................19 4.2.3 Visual fatigue ......................................................................................................20

4.3 POPULAR CONCERNS................................................................................................21 4.3.1 Radiation.............................................................................................................21 4.3.2 Pregnancy...........................................................................................................21

5 BREAKS AND STRETCHING.......................................................................................22 5.1 BREAKS ...................................................................................................................22 5.2 STRETCHING.............................................................................................................23

6 RECAP ..........................................................................................................................24 7 RESOURCES................................................................................................................27 APPENDIX: OFFICE ERGONOMICS SELF-ASSESSMENT CHECKLIST .........................29

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1 Introduction Computerization has resulted in increased job demands and mental stress, which can be associated with muscle tension and physical strain that can eventually lead to a Cumulative Trauma Disorder (CTD) complaint. Computers, while increasing productivity in the office have resulted in ergonomic stressors that can be directly linked to increased CTDs including tendonitis, carpal tunnel syndrome, and some forms of back pain. Ergonomics is the study of the way in which we work and interact with the characteristics of the environment; it includes finding ways to be more efficient, as well as ways to protect people from sustaining injury. The purpose is to design the job to fit the worker rather than physically forcing the worker’s body to fit the job by creating a comfortable environment with the application of ergonomic principles, such as:

♦ avoiding overreaching, repetition, awkward posture, direct pressure, fatigue and force; ♦ understanding how to adjust our work environment to accommodate our individual needs; ♦ applying principles of good posture and habits.

Common injuries associated with poor office ergonomic habits include the following:

Injury Cause Tendonitis Repetitive movements

Carpal tunnel syndrome Repetitive work with a bent wrist

Back strain

Slumped positions, bending, lifting

Neck/shoulder tension

Forward head posture, swayed back position

Circulatory problems Static posture

The afore-mentioned injuries are a result of risk factors/abnormal body motions such as:

♦ Non-ergonomic workstation design. ♦ Repetitive movements – e.g. typing for long periods without rest. ♦ Awkward postures – e.g. neck bent too far forward or wrists bent too far back. ♦ Static postures – e.g. sitting for long periods without getting up or stretching.

Restricts blood flow to working tissues ♦ Reaching- e.g. reaching awkwardly such as down into a side drawer or behind chair, multiple

times a day.

The purpose of this manual is to highlight risk factors/ abnormal body motions related to office work tasks and work environment, solutions to common physical problems related to computer use and presentation of health issues. This will in turn attempt to facilitate employee behavioural modifications and injury prevention through instruction on proper ergonomic computer workstation set up, proper posture, identification of risk factors and exercise/stretching instructions.

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2 Setting Up Your Workstation It’s important to be aware of how the design and arrangement of your equipment can impact your comfort, health, and productivity. Your computer workstation is the environment around your computer which includes furniture (chair and desk), computer equipment (computer, monitor, keyboard, and mouse), accessories (document holder, footrest, telephone, palm rest) and ambient factors (noise, lighting, temperature, etc.). 2.1 Chair It all begins with the chair as the chair may be the most important part of the workstation. The chair must fit you and be appropriate for your tasks. Sitting properly in a well-fitted chair helps to limit back strain and discomfort. Since more than one person may be using the computer, it’s important to know how to select a chair with several ergonomic features. The features of a "good" ergonomic chair are as follows:

♦ Adjustability ▪ Seat height range: Seat height should be adjustable to the height recommended for the worker(s) who will use it. ▪ Backrest: The backrest should be adjustable both vertically and in the frontward and backward direction.

♦ Seat depth - Seat selection should be based on that which suits the tallest and the shortest users.

♦ Stability - A five-point base is recommended for stability of the chair.

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In setting up your chair you should be able to: ♦ Adjust the seat height so your feet rest flat on the floor or use

a supportive footrest. Sit upright in the chair with the lower back against

the backrest and the shoulders touching the backrest.

Thighs should be parallel to the floor and knees at about the same level as the hips (equal to or slightly lower).

Back of knees should not come in direct contact with the edge of the seat pan. There should be 5.08-10.16 cm (2-3 fingers) between the edge of the seat and the back of the knee.

Use a footrest when attempts to adjust your chair and the rest of the workstation fail to keep your feet on the ground.

Ensure that you have some space (5-7 cm) between the top of your thighs and the underside of your workstation.

Have enough space under your work surface so that you can pull yourself all the way up to the edge of the desk with room for your legs and knees to fit comfortably.

♦ Check that the seat pan depth is such that the user can maintain contact with the backrest in the lumbar area and avoid increased pressure on the back of legs and behind the knees.

Sit in the chair and push your hips back as far as they can go against the chair back.

♦ Check that the adjustable arm rests do not impede access to the work station or arm movement. The arm rests should be removable and the distance between the arm rests should be adjustable.

Adjust the height and/or width of the armrests so they allow the user to rest arms at their sides and relax/drop their shoulders while keyboarding. o If the armrests are too high, they will elevate the shoulders which can cause

stiffness or pain in the shoulders and neck. Don’t use the armrests to slouch.

o If the armrests are too low, they promote slumping and leaning to one side.

Elbows and lower arms should rest lightly on armrests so as not to cause circulatory or nerve problems.

If your armrests are in the way, remove them.

♦ Adjust the height of the backrest to support the natural inward curve of

the lower back (100-119 degree reclined angle). The upper and lower back must be supported.

A chair that maintains the normal alignment of the spine (S-curve) will relieve fatigue and discomfort.

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Tips and recommendations: ♦ The ability to swivel 3600 and move the chair around improves access to work materials,

eases sitting down and standing up and reduces twisting stresses on the spine. ♦ Avoid static positions; don’t stay in one position (sitting or standing) for extended periods of

time. ♦ When performing daily tasks, alternate between sitting and standing or take small walking

breaks throughout the day. ♦ The chair back should have lumbar support. It may be useful to use a rolled towel, lumbar roll

or cushion to support the low back. Be sure it fits properly and fits the size of your curve. Improperly fitted pillows or cushions may be worse than no cushion at all.

♦ A foot rest should be provided if your feet cannot rest comfortably on the floor while seated at the workstation.

Health Notes:

♦ Sitting properly in a well-fitted chair helps to limit back strain and discomfort. Chairs that have an adjustable seat, backrest and armrest are preferable.

♦ Sitting for long periods of time can cause increased pressure on the intervertebral discs (spongy discs between the vertebra).

♦ Sitting is also hard on the feet and legs. Gravity tends to pool blood down into the legs and feet and create a sluggish return of blood to the heart.

♦ Change your position every 20-30 minutes to increase blood circulation, and avoid muscle fatigue.

♦ Footrests raise the knees and take much of the strain off the pelvis. Each time you adjust your chair, you should adjust your footrest as well. This allows you to shift to another position, which will prevent fatigue caused from sitting for long periods of time.

♦ Avoid using the base of your chair as a footrest, as doing so can cause your knees and trunk to bend down and forward, forcing you to hyperextend your back in order to stay erect and see the computer screen.

2.2 Monitor

The monitor is an integral part of a computer workstation. When placed in the wrong position the user is forced to work in a variety of awkward positions which may lead to discomfort and injury such as eye irritation, blurred vision, dry burning eyes and headaches. Common complaints include discomfort, aches and pains in the neck and shoulder, and eye strain. ♦ Sit directly in front of the monitor and keyboard/mouse to avoid excessive twisting or bending

of the neck.

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♦ Once the chair and work surface height are properly adjusted, the computer monitor should be placed so the top of the screen is at or just below eye level (approximately 5-7 cm below seated eye level) when seated in an upright position.

If the monitor is too low, use monitor risers or unused binders or books to elevate. Individuals who wear bifocals and trifocals may need to place the monitor lower

than this to maintain comfortable (neutral) neck posture. (See Health Notes)

♦ Monitor viewing distance should be about one arm’s length away from the screen (46-76 cm

from user) when seated comfortably in front of the keyboard. Tips and recommendations: The following suggestions can help prevent the development of eye strain, neck pain and shoulder fatigue while using your computer workstation: ♦ Make sure the surface of the screen is clean. Dust buildup can make distinguishing

characters difficult and may also contribute to glare and reflection problems. ♦ Adjust brightness and contrast to optimum comfort. ♦ Reduce glare by careful positioning of the screen.

Place screen at right angles to windows. Adjust curtains or blinds as needed. Adjust the vertical screen angle and screen controls to minimize glare from

overhead lights. Other techniques to reduce glare include use of optical glass glare filters, light

filters, or secondary task lights. ♦ Use screen scroll bars to ensure that what is being viewed most is in the center of the monitor

rather than at the top or bottom of the screen.

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Health Notes: ♦ Get regular eye check-ups. ♦ Individuals who wear bifocal and trifocal lenses have to pay

particular attention to the placement of their monitor. They often unknowingly tilt their heads backwards so they can read the screen through the lower portion of their glasses. This can sometimes lead to neck, shoulder, and back discomfort. Potential solutions include either lowering the computer monitor or purchasing glasses designed specifically for working at the computer.

♦ Incorrect positioning of the screen and source documents can result in awkward postures. Adjust the monitor and source documents so that your neck is in a neutral and relaxed position.

2.3 Keyboard and Mouse

Adjusting the keyboard and mouse properly can help to prevent the development of ergonomic problems occurring in the shoulder, elbow, forearm, wrist, and hand. ♦ The keyboard and mouse should be located at a height that allows

the user’s forearms, wrists, and hands to be parallel to the floor (elbow is approximately at a 900 angle).

♦ The surface of the keyboard should generally be lower than a typical writing surface in order to permit the best posture.

Underdesk adjustable height keyboard/mouse trays should be used to accommodate this need when the work surface height cannot be adjusted.

♦ Adjust keyboard height so that the shoulders can relax and allow arms to rest at sides.

♦ The slope of the keyboard may need to be adjusted so that it is flat in order to ensure that your wrists are straight and not bent back while you are typing.

♦ Press the keys gently; do not bang them or hold them down for long periods. Keep your shoulders, arms, hands, and fingers relaxed.

♦ The mouse should be located next to the keyboard, as close as possible and at the same height, to minimize reach.

♦ The back of the wrist should be kept flat (in a neutral position) and your hand, wrist, and forearm should be straight and slightly above the mouse.

♦ Do not rest the hand on the mouse when you are not using it. Rest hands on your lap when not entering data.

♦ A padded wrist rest will help to keep your wrist in a straight and neutral position while typing and keep your arms off the sharp edges of the work surface.

♦ Do not rest your wrists or hands on wrist rest when typing. Wrist rests are designed to provide support only during breaks from typing.

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Tips and Recommendations: ♦ An articulating keyboard tray may provide the best possible positioning of input/ pointing

devices. It should accommodate the mouse, provide leg clearance, and have an adjustable height and tilt mechanism. The tray should not push you too far away from other frequently used items, such as your telephone.

♦ Adjust the keyboard height so that your shoulders are relaxed, your elbows are in a slightly open position (100 to 110 degrees) and your wrists and hands are straight.

♦ Use the keyboard “legs” (adjustable tabs located underneath keyboard) to find an angle that allows your wrists to be in a neutral position.

♦ If you sit in a forward or upright position, try tilting your keyboard away from you at a negative angle. If you are reclined, a slight positive tilt will help maintain a straight wrist position.

♦ Wrist rests can help to maintain neutral postures and pad hard surfaces. Wrist rests should

only be used to rest the palms of the hands between keystrokes. Resting on the wrist rest while typing is not recommended.

♦ Avoid using excessively wide wrist rests, or wrist rests that are higher than the space bar of your keyboard.

♦ Place the mouse/ pointing device as close as possible to the keyboard.

♦ Placing the mouse on a slightly inclined surface, or using it on a mouse bridge placed over the # keypad, can help to bring it closer.

♦ Use your whole arm to move the mouse and not just your wrist.

Negative Slope Keyboard Positive Slope Keyboard

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Health Notes:

♦ Placing the mouse or keyboard too far away, too low, or too much on one side can cause shoulder, wrist, elbow, and forearm discomfort. Placing the keyboard directly in your immediate reach zone offers natural comfort and maximum hand-to-eye coordination.

♦ If your work surface is too high, then you’re straining your arms and shoulders in order to “reach” the keyboard. This requires continuous muscular effort and it may also hinder blood flow, which adds to further discomfort and risk of injury. It also causes you to bend your wrists forward and place stress on the forearm muscles. If your workstation is too low, then you are placing stress on your arms and back in order to “bend” to a closer position.

♦ Pounding the keys harder than necessary can cause tingling in the fingertips and pain in the finger joints. Pressing the keys rather than lightly touching them, strains the tendons of the fingers, hands and forearms. Pecking at the keys instead of touching them lightly usually requires lifting the remaining fingers and thumb, which over time, such repetitive movements can lead to forearm tendonitis and de Quervain’s disease (inflammation of tendons in thumb).

2.4 Layout/Desk/Equipment and Accessories All aspects of your workstation play a role in your health. The positioning of your tools is as important as the manner in which you use them. Office equipment can range from computers and telephones, lights, staplers to even paper clips. Consider all the reaching you do in a given day while sitting at your desk. Perhaps you can rearrange your belongings in a manner that will reduce the amount of reaching, straining and twisting you do to your body. The following suggestions should help you organize your office workstation.

♦ The work area should be large enough to accommodate you, allowing the full range of motions involved in performing required tasks, and provide room for the equipment and materials that make up the workstation.

♦ The desktop should be organized so that frequently used objects are stored close to the user to avoid excessive extended reaching and should only be on the work surface if they are in constant use.

♦ Place items that you use frequently in the primary zone and items that you use occasionally or for short periods in the secondary work zone.

♦ Place material that you use occasionally farther away. Use storage areas such as overhead shelves, filing cabinets, and desk drawers for items that you use infrequently.

♦ The area underneath the desk should always be clean and uncluttered to accommodate the user’s legs and allow for stretching.

♦ Position your desk lamp (if you use one) so that it illuminates source documents without causing either glare on the computer screen or direct illumination to your eyes.

♦ If a document holder is used, it should be placed at approximately the same height as the monitor and at the same distance from the eyes to prevent frequent eye shifts between the monitor screen and reference materials.

♦ When working at a sit-stand workstation, remember that standing in a static posture is even more tiring than sitting in a static posture. Movement is important, so change positions regularly (e.g., sit/stand/ walk), wear comfortable shoes and use a foot stool.

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♦ When working at a student/client services workstation you want to check the monitor height, reaching (vertical and horizontal) and neck posture.

Stand up if students/clients are infrequent. Organize the transaction counter to create a service

location that does not require leaning over the computer. Place objects on counter rather than into the hand.

Tips and recommendations: ♦ If the work surface cannot properly accommodate a keyboard/mouse and monitor (i.e. the

surface is too high or too shallow) then an adjustable under desk keyboard/mouse support device should be used.

♦ If telephone use is a major component of the job (such as reception areas), especially in combination with computer work, a telephone headset should be provided.

For individuals who do not use the telephone quite as much, a telephone handset attachment is an alternative solution to minimize “cradling” the handset between the ear and shoulder.

Place the phone on the side of your non-dominant hand (i.e., left side if right-handed, right side if left-handed)

♦ A document holder should be used if documents are referred to during typing. The document

holder should: Be stable and adjustable (height, position, distance, and angle of view). Support your document on either side of the monitor. Be at the same height and distance from your eyes as the screen to avoid frequent

changes of focus and you should be able to look from one to the other without moving your neck or back.

Health Notes: ♦ If materials that you use often are too far away, repetitive reaching can add to neck, shoulder, and upper back discomfort. Materials that are disorganized and scattered about may contribute to a stress related state of mind. ♦ Prolonged stationary standing can result in decreased

blood flow to the tissues causing swelling, muscle fatigue and pain; sore feet; poor posture, and increased low back pressure.

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2.5 Lighting Lighting not suited to working with a computer is a major contributing factor in visual discomforts including eyestrain, burning or itching eyes, and blurred or double vision. Lighting for computer work stations should be set up to minimize glare and visual discomfort.

Tips and recommendations:

♦ Use the following recommendations to reduce eyestrain and eye fatigue: Close drapes/blinds to reduce glare Adjust lighting to avoid glare on screen (light source should come at a 90 degree

angle, with low watt lights rather than high). Avoid intense or uneven lighting in your field of vision. Place monitor at a 90 degree angle to window (where possible). Use a good quality anti-glare filter, monitor shield, or light diffusers to reduce glare

from overhead lighting. Dim or turn-off overhead lights and use a task light. Position computer work stations between rows of overhead lights rather than

directly below. Position computer work stations at right angles to windows (e.g. operator does not

face window or have back to window). Utilize partitions to block light from windows and overhead lights. Tilt the monitor slightly downward to reduce reflection from overhead lights.

Health Notes:

♦ Straining to view objects on the screen can lead to eye fatigue.

♦ Eye strain can result from dry eyes and looking at the monitor for prolonged periods of time. Blinking helps lubricate your eyes.

Post a “Blink” post-it note on your monitor to remind you to blink while working.

Take regular breaks to rest eye. Look around and look away from the screen for a few seconds. Focus vision on distant objects

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2.6 Environmental Controls Two main factors are to be considered: Thermal Comfort and Acoustic Factors. For thermal factors, make sure that the temperature range and air movement are acceptable, draughts are absent, and humidity levels are acceptable. For more information, you can refer to http://ehs.concordia.ca/ih/iaq.html Annoying noise from computers and other workstation equipment, even at low levels, creates stress that tenses your muscle which can increase injury and lower productivity. High noise levels can also reduce concentration. Sources of noise include keyboard typing, computer fans, photocopy machines, printers and building ventilation systems. To know if the acoustic factors are acceptable, make sure that normal conversation can be held without difficulty, and that equipment noise is minimized at the source. The objectives of limiting office noise are to prevent interference with verbal communication; prevent stress and annoyance; and minimize interference with concentration. Use low volume music such as light classical music to mask the hum of any fan or other sound sources. 3 Use of Laptops and Personal Digital Assistants (PDAs) 3.1 Laptops Laptop computers have several advantages for users in terms of being lightweight and highly portable. The portability of the laptop enables users to take their work anywhere- to clients, work, home offices and on the road. However, laptop computers are not recommended as primary computers. The laptop design features present inherent ergonomic problems because the keyboard and the screen are attached, forcing the user to endure awkward and unhealthy wrist, arm, shoulder, and neck postural compromises which may lead to discomfort or injury. The attached design means that using a laptop is a tradeoff between poor neck/head posture and poor hand/wrist posture because you cannot have both the screen and the keyboard in a satisfying position. Laptop computers are not designed for prolonged use.

3.1.1 Laptop Accessories To use your laptop like a PC on your desk and increase comfort while using a laptop consider using the following accessories:

♦ An adjustable height and tilt laptop stand or laptop drawer or docking station to position the top line of the screen a bit below eye level which will allow you to see the screen without bending or rotating your neck enhancing a neutral posture and reducing stress and strain to the musculoskeletal system.

Laptop Swivel Stand Laptop Desk Stand Holds and raises laptop, swivels and tilts, Holds and raises laptop to adjustable height, offering comfortable viewing height and angle. base platform has storage for keyboard and accessories.

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♦ An external mouse and keyboard with a negative-tilt keyboard tray

Position them at a height that allows your upper arms to hang loosely from the shoulder and your forearms to extend horizontally to the floor towards the keyboard.

♦ An external mouse allowing movement of hand. ♦ An external monitor.

3.1.2 Laptop design features associated with musculoskeletal symptoms Comparisons are made with to standard desktop computer systems.

Health Note: • Laptops can put strain on the user’s neck and back and lead to eye strain and shoulder

fatigue.

3.1.2 Laptop Tips Here are some tips to increase comfort while using a laptop:

♦ Attach an external mouse instead of using the small constricted touchpad or trackball. ♦ Add an external keyboard. ♦ Avoid pounding on the keys when typing. ♦ Angle the screen so that it is perpendicular to your line of sight, if lighting permits. ♦ Position the keyboard at elbow height, and keep your wrists

straight while typing. Experiment with table height, chair height and keyboard angle to maintain neutral wrist postures.

♦ Be aware of your posture: Avoid rotating or bending your neck and head forward

to see the screen.

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The hands and wrists should be kept in a straight wrist posture when typing and should not be resting on a palm rest, table, or lap while typing. Wrist and palm rests are designed to provide support during breaks from typing.

♦ Maintain a comfortable viewing distance from your screen; about 45-75 centimeters. ♦ Use a chair with proper lumbar support or roll up a towel and place behind lower back. ♦ Clean the screen regularly using appropriate antistatic cleaning materials. ♦ If you are seated in a side chair or couch, use a pillow to support your arms while typing. This

will help you maintain neutral arm, wrist, and hand postures. ♦ Incorporate mini-breaks every 20 to 30 minutes to break up repetition and static postures. ♦ Give your eyes a break every 15-20 minutes by closing them or looking off in the distance. ♦ Stay fit as regular exercise can improve your posture and reduce stress.

3.1.3 Transporting Laptop Backpacks can cause neck, shoulder, and back discomfort if not selected and worn properly. You may want to: ♦ Eliminate unnecessary baggage from your briefcase/ backpack, the less demand placed on

the body the better. Reducing the number of peripherals you carry will greatly

reduce your bag’s weight and the subsequent stress and strain on your shoulders.

Use multiple compartments. Arrange items so they don’t shift around. Place heaviest items close to your back.

♦ Carry your laptop in a case with a wide padded shoulder strap; air filled cushions and a handle.

♦ Keep the load close to you by wearing snug shoulder straps over both shoulders and positioning the backpack between your shoulders and hips to reduce muscle strain on your shoulders and back.

♦ Use backpack waist belt to shift work to your trunk and hip. ♦ Use a wheeled luggage cart when possible for heavy loads and long distances.

3.2 PDAs PDAs can store, organize and retrieve information quickly, but like all computing devices, PDAs can also lead to discomfort if used repetitively. As with computers, reducing the amount of repetitive motions can reduce the chances of injury.

3.2.1 Tips and recommendations for PDA use Reduce the risk of injury by reducing the amount of repetitive motions by performing the following:

♦ Most repetitive motions come from entering text or information into your PDA. Since the area to enter text is small, inputting of large amounts of text subject users to hand or wrist pain. Therefore, avoid entering data on your PDA. Use a comfortable keyboard and big screen to enter all your contacts, appointments, and information, then synchronize using your PDA for information retrieval.

♦ Learn PDA shortcuts. Many PDAs offer combinations for copying and pasting text which is much easier than retyping all that information.

♦ Some software programs let you configure the entire screen to accept stylus input, instead of just a small area at the bottom of the screen. (Bigger hand motions means less stress)

♦ Clean screen. A clean screen will help ease your eyes and may prevent

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eyestrain.

3.2.2 PDA Product Add-Ons The following products can assist in making your PDA more ergonomic:

♦ An external portable keyboard Allows you to enter information by typing on a

standard keyboard instead of writing. Often used by those who use their PDA as a

replacement for their laptop while traveling. ♦ Stylus with wider ergonomic grip

Since styluses are built thin to fit easily into the PDA casing, a tight pinched grip is required to hold them. Individuals experiencing hand or finger pain from prolonged usage may appreciate a stylus with a wider grip that makes it much easier to hold on to.

♦ Screen magnifiers to enlarge view of text on small screens. ♦ Thin-film screen protectors to protect screen from scratches.

4 Ergonomic Health Issues

4.1 Cumulative Trauma Disorders (CTDs)

Cumulative trauma disorders are also known as Repetitive Strain Injuries (RSI’s) or Work-Related Musculoskeletal Disorders (WRMD). They are disorders that are caused by over-use or misuse of the muscles, nerves, and tendons of the human body. Contributing factors for CTD include any or a combination of the following: ♦ Repetitive Tasks - Performing the same movement over and over, such as typing or using

a mouse, e.g., sitting in the same position while typing with bent or flexed wrists. ♦ Awkward or Static Postures- Working in an awkward position or holding the same

position for a long time. ♦ Fast Pace- Having to work quickly. The faster the pace, the shorter and less productive the

recovery time becomes. ♦ Duration of Task with Insufficient Recovery Time- Inadequate work breaks.

4.1.1 CTD Symptoms ♦ Tingling or numbness in the hands or fingers ♦ Pain in fingers, hands, wrists, or shooting pain up into the

arms and forearms. ♦ Loss of strength or coordination in the hands. ♦ Numbness or discomfort in the hands which wakes you up at

night.

The problem is that since the sensations tend to pass within minutes or hours of occurrence, people do not consider them as a serious medical problem. However, continuous exertions beyond normal fatigue levels can result in muscle damage, discomfort and impaired performance. Pain or discomfort that persists or impairs your normal activities should be evaluated by a qualified medical practitioner for diagnosis of the disorder, assessment and prescription of appropriate treatment and identification of causal and aggravating factors.

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4.1.2 Prevention Increased awareness of your posture and work habits are necessary to enable you to work safely and avoid the problems associated with CTDs. The use of proper keyboard and pointing device techniques, rest breaks, and proper workstation set up can significantly reduce the risks of developing an overuse injury such as CTD. Proper use of your computer must be considered as just one element as the effects of repetitive movements associated with using a computer can be compounded by other work or leisure activities to produce or aggravate physical problems or disorders.

4.2 Common Ailments/Disorders The following table illustrates common categories of Cumulative Trauma Disorders.

Common Forms Common Symptoms and Common Body Areas Affected

Common Causes

Muscle Pain Persistent pain, especially in the hands.

Work place design/ Layout

Tendonitis

Inflammation of the tendons resulting in pain, swelling, tenderness and redness of hand, wrist and/or forearm. Difficulty in using hand.

Job activities/ Habits/ Repetitive movements

Epicondylitis Inflammation at the elbow causing pain.

Repetitive work/ Work Layout

Carpal Tunnel Syndrome

Compression of median nerve in hand causing tingling, pain and numbness in thumb and fingers, especially at night. Can cause sleep interruption.

Constant constraint on wrists/ Repetitive work with bent wrist

Tenosynovitis Inflammation of tendons and/or tendon sheaths of the hand/wrist causing aching, tenderness, swelling, pain, and difficulty using hand.

Stress/ Repetitive movements/ Sudden increase in workload or introduction of new task

Ganglion Cyst

Lump under the skin on the back of the hand and inside wrist causing pain and weakness.

Repetitive hand movement/ excessive bending and/or deviating wrist

Bursitis Inflammation in the shoulder and elbow Kneeling/ pressure at the elbow/ repetitive shoulder movements

Plantar Fascitis

Inflammation in the arch of the foot Pronation (the foot rolls outward at the ankle, causing a break down of the inner side of the shoe).

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4.2.1 Carpal Tunnel Syndrome In the center of the wrist is a space called the carpal tunnel where a major nerve and tendons pass from the forearm into the hand. When swelling occurs in the carpal tunnel, pressure is put on the median nerve, causing carpal tunnel syndrome. Symptoms:

♦ Pain ♦ Numbness ♦ Tingling ♦ Burning in the hand, fingers, wrist

Prevention:

♦ Keep the wrist straight as much as possible. ♦ Reduce repetition by performing different activities or

taking mini breaks. ♦ Do not rest on the desk or the wrist rest while typing. ♦ Position keyboard and mouse so there is a 90-110 degree angle in the elbow while

working. ♦ Place the palm of your hand on the mouse to keep your wrist straight.

Signs that your condition requires attention: ♦ Painful tingling in the hand during the night, frequently painful enough to disturb sleep. ♦ A feeling of uselessness in the fingers, which you can sometime describe as feeling swollen,

even though little or no swelling is apparent. ♦ Tingling during the day, commonly in the thumb, index, and ring fingers. ♦ A decreased ability and power to squeeze things. ♦ A loss of strength in your fingers. ♦ Unable to differentiate hot from cold by touch. ♦ Trouble performing simple tasks such as tying your shoes or picking up

small objects. ♦ Symptoms that persist after a night’s rest. ♦ Symptoms that interfere significantly with work or daily living activities. Typing and RSI: Many people spend a great part of the workday typing. Some sit down and peck at the keyboard until they finish their work, even if it takes several hours. Most RSI’s are the result of untrained workers and unhealthy work patterns. We routinely force the muscles of our hands and arms to repeat unnatural and dangerous movements, hyper-extending our wrists, twisting our hands to one side or the other, over and over again, all day long. A great tip is to learn to type.

4.2.2 Stress A number of studies have indicated that occupational stress, both physical and mental are an increasing problem in workplaces. The impressive speed with which information technology has been integrated into the workplace has brought with it new levels of stress that create a cumulative effect: ♦ The pace of office work has become more intense; a fast pace

of work does not allow the body adequate recovery time between repetitive or forceful movements.

♦ There is more pressure for perfection. ♦ Work processes have changed.

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The above causes resulting from the changing relationship between the worker and his or her immediate surroundings has become a major contributor to the increase of reported injuries in the office. Below is an outline of possible causes and effects of stress.

Causes

♦ Lack of job satisfaction and job mobility

♦ Repetitive, demanding work without rest breaks

♦ Discrimination or harassment

♦ Muscular or mental fatigue

Effects

♦ Migraines ♦ Insomnia ♦ Fatigue ♦ Ulcers ♦ Heart

problems

Tips and Recommendations: ♦ Become aware of stress management facilities in the organization. ♦ Allow for self pacing. ♦ Acquire greater control over job tasks. ♦ Take frequent breaks. ♦ Participate in group discussions and events. ♦ Take action on problem areas. ♦ Seek help from a professional.

4.2.3 Visual fatigue Visual fatigue can occur when the eyes are focused on a nearby object for a long time. This occurs because the eye muscles must work harder to view an object that is closer than about 6 meters. Improper lighting can also hasten the development of visual fatigue. Though eyestrain is an annoying symptom, it does not mean that continuing to work at a computer will damage your eyes. If you are still experiencing blurred vision or eye irritation and fatigue even after you have adjusted the lighting, glare and monitor screen in your workstation, you should visit an optometrist. Also if your job requires you to use a computer for more than one hour each day, be sure to have a complete yearly visual assessment.

Common computer-related eye problem and solutionsComplaint Possible Problem Possible Solution/Treatment

♦ Incorrect glasses/spectacles or contact lens prescription

♦ Eye examination

♦ An accommodative spasm ♦ Gaze away from the monitor every 15 minutes

Blurred Vision

♦ Tear film abnormality ♦ Artificial tear drops ♦ Air currents (from ventilation system) on

work station ♦ Air supply deflectors

♦ Lid or eye inflammation ♦ Eye examination

Aching, burning, and stinging eyes

♦ Improper spectacles or contact lens prescription

♦ Eye examination

Headache ♦ Poor monitor resolution ♦ Large (not over 48 cm), high quality monitor or increase font size.

Neck, shoulder and back pain

♦ Poor posture - leaning forward or tilting head back to see/focus on the screen

♦ Eye examination

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Health Notes:

♦ Set the monitor as far from the eye as comfortable. ♦ Give your eyes frequent breaks by looking up and focusing on distant objects. ♦ Have your eyes examined regularly.

4.3 Popular Concerns

4.3.1 Radiation Numerous studies have shown that ionizing radiation (such as X-rays) and non-ionizing radiation (such as ultraviolet) emissions from computers are negligible under normal operating conditions. All electrical equipment can produce non-ionizing radiation. Computer monitors have internal shielding that reduces non-ionizing radiation to safe levels. Computer users who sit at typical distances from their monitors receive extremely low exposures.

4.3.2 Pregnancy A study conducted by the National Institute for Occupational Safety and Health (NIOSH) and the American Cancer Society found no increase in the risk of spontaneous abortion (miscarriage) associated with using computers in the workplace. Working with computers does not increase a woman’s risk of delivering a baby of reduced birth weight or delivering prematurely. The conventional scientific opinion is that computer use is not a radiation hazard for the pregnant worker. However, computer workstations and work tasks may have to be modified to accommodate pregnant workers. Ergonomic principles that apply to non-pregnant workers also apply to pregnant workers throughout the duration of their pregnancy. Tips and Recommendations:

♦ Limit standing time and avoid prolonged sitting/standing. ♦ Vary tasks to avoid static postures. ♦ Use foot rests to comfortably shift weight. ♦ Reduce repetitive tasks as much as possible and keep wrists

straight. ♦ Adjust work surfaces to accommodate change in body structure.

Health Notes:

♦ The natural S- curve in the spine is modified during pregnancy as the curve in the lower back increases. As a result the pregnant worker’s lower back muscles have to work harder to maintain balance of the body and can increase stress on the spine. The muscles also have to work harder when standing, so the pregnant worker often feels discomfort and pain in the lower back after standing for long periods of time.

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♦ Moderate walking should be encouraged throughout the pregnancy. Walking causes the leg muscles and veins to pump blood upward from the feet and helps prevent minor swelling of the ankles.

♦ Approximately ¼ of all pregnant women experience Carpal Tunnel Syndrome because of the increase in fluids in the body. Thus, repetitive motion can increase the severity of the symptoms by irritating the tendons and placing added pressure on the median nerve.

5 Breaks and Stretching The importance of taking breaks and stretching during the workday should not be underestimated. They are just as important as having a proper workstation set-up. In fact, even working at the most ergonomic workstation is not a guarantee that the user will not experience any pain or discomfort. The human body is not designed to be in one position for hours at a time. 5.1 Breaks Repetitious static work such as working at the computer for a long period of time is very fatiguing on your upper extremities as well as your eyes. It is important that breaks from working at the computer be taken every 20 to 40 minutes in order for your body to rest and recover. Taking a short break (3 to 5 minutes) does not mean that you have to stop working. Such work breaks are one of the most effective actions you can take to prevent the discomforts of prolonged computer use. Tips and Recommendations:

♦ It is important to change positions periodically. Sitting in one position or leaning on your arms for an extended period of time can interfere with circulation.

♦ Retrieving a document from the printer, using the copy

machine, standing up while on the phone, walking down the hall to confer with a colleague, or getting a drink of water or coffee are simple, productive ways to break up your computer tasks. This allows you to rest and use different muscles.

♦ Make an effort to be away from the computer during lunch.

♦ If you type continuously, a good rule of thumb is to do other tasks for ten minutes every hour. ♦ If you perform lighter work at the computer, do other tasks for fifteen minutes every two hours. ♦ Both back and seat can tilt on modern chairs. It's good for the back if you sometimes lean

back and rest in this position, but not for too long as this can strain the neck muscles.

Health Notes: ♦ Prolonged, static postures will inhibit blood

circulation and take a toll on your body. Looking at the monitor for a prolonged period of time without taking a break can fatigue the muscles of the neck and shoulder that support the head.

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♦ Work breaks can help prevent RSIs by allowing you to rest, stretch or change positions when needed.

♦ Always try to maintain the natural curves in your back (S- curve). These curves provide strength and support for your back. This is especially important when sitting for long periods.

♦ Change positions frequently when sitting or standing for prolonged periods. When standing, use a footstool to prop one foot up, and switch sides every so often.

♦ Looking at the computer screen for a while causes you to blink less often, and exposes more of the eye surface to the air. Blinking your eyes rapidly for a few seconds refreshes the tear film and clears dust from the eye surface.

♦ Avoid eye fatigue by resting and refocusing your eyes periodically. Look away from the monitor for a minute or two and focus on something in the distance. This lets the eye muscles relax.

• Also, you can rest your eyes by covering them with your palms for 10-15 seconds. 5.2 Stretching It is important to stretch occasionally during the day. Vigorous exercises are not necessary, whereas, regular stretches can reduce muscle fatigue and reduce stress. Stretching and exercise can help ease the discomforts and harmful effects of repetitive motions and awkward or static postures by:

♦ Releasing muscle tension ♦ Reducing eyestrain ♦ Reducing the risk of aches and pain ♦ Improving circulation ♦ Improving flexibility ♦ Increasing strength and endurance ♦ Increasing energy levels ♦ Increasing resistance to illness ♦ Decreasing recovery time from illness

Tips when Stretching:

♦ Perform stretches gently; movements should be slow and controlled.

♦ Don’t do any stretches that cause pain; you should feel a gentle stretch of the muscle.

♦ Don’t worry about how far you can stretch. ♦ Once you feel a stretch, HOLD each stretch for 15-20

seconds to a minute; DO NOT BOUNCE. ♦ Repeat each stretch three to five times. ♦ Make sure to do stretch with each arm or leg. ♦ Do a variety of exercises or just those that relieve tension

in a particular area. ♦ Remember it is important to stretch frequently, in the opposite direction of the line of work. Ex., If you have been sitting during your work task, stand upright, place your hands on your lower back for support and bend backwards several times.

If you have concerns about an existing medical condition or injury, consult your physician before you do any of the suggested exercises.

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For further information on stretches you can do at the office visit our web-site at

http://ehs.concordia.ca/ih/ergo.html 6 Recap Remember that a properly adjusted workstation can help minimize awkward postures, as proper neutral postures allow you to work with minimal stress on the musculoskeletal system. Listen to the signals your body sends you. Examine your work practices, workstation set up, and work area and make the appropriate adjustments and changes. See the Self-Assessment Checklist in the Appendix to evaluate your workstation and make changes where possible. After spending a day in front of the computer, ask yourself, how do you feel? Do you have sore eyes or headaches? Do your wrists, arms, shoulders, back, legs or neck feels stiff or uncomfortable? Remember to:

♦ Place the monitor directly in front of you. ♦ Place frequently used items, such as keyboards and

pointing devices where you can reach them easily. ♦ Position keyboard and mouse in order to maintain neutral

wrist position. ♦ Adjust your chair so your feet and back are well

supported. ♦ Allow for regular breaks and stretches throughout the

day.

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Adjusting Your Workstation

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Maintain Neutral Posture

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7 Resources Concordia University Office Ergonomic Manual, November 2000 http://ehs/pdf/ih/Office_Ergonomics.pdf Websites: Office Ergonomics Standard: Ergonomic Requirements for Moderate and Intensive Computer Users http://www.utoronto.ca/safety/ergoweb/ergostd.htm CDC Computer Workstation Ergonomics http://www.cdc.gov/od/ohs/Ergonomics/compergo.htm Ithaca College Environmental Health & Safety Workstation Ergonomics: Make Your Work Environment Conform to You http://www.ithaca.edu/safety/ergonomics University of Victoria Occupational Health and Safety: Ergonomics http://ohs.uvic.ca/ergonomics/index.html Yale University Ergonomics: Computer Workstations Ergonomics http://www.yale.edu/ergo/cw.htm Healthy Computing http://www.healthycomputing.com/office U.S. Department of Labor OSHA: Computer Workstations http://www.osha.gov/SLTC/etools/computerworkstations/index.html Evaluating your Computer Workstation: How to make it work for you http://www.cbs.state.or.us/osha/pdf/pubs/1863.pdf http://www2.umaine.edu/SEM/Documents/MiscTrainingAndGuides/VDTguide.pdf Canada’s National Occupational Health & Safety Resource: Ergonomics http://www.ccohs.ca/oshanswers/ergonomics Ergonomics Fact Sheet: Working with Laptop Computers http://www.gov.ns.ca/enla/healthandsafety/ergonomics/docs/LaptopComputers.pdf Office Ergonomics http://www.pp.okstate.edu/ehs/modules/ergo/work.html CUergo: Computer Workstation Ergonomic Guidelines http://ergo.human.cornell.edu/ergoguide.html Musculoskeletal Disorder http://www.pc.ibm.com/ww/healthycomputing/vdt9-msd.html

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UCLA Ergonomics, Home of the Bruins http://ergonomics.ucla.edu/ How to create a comfortable working environment http://vertigo.hsrl.rutgers.edu/ug/ergonomics.html Healthy computing http://www.pc.ibm.com/ww/healthycomputing/index.html UMDNJ Ergonomics Guide and Tips for Computer Users http://www2.umdnj.edu/eohssweb/ergo/index.html International Labour Organization: Your Health and Safety at Work: Ergonomics http://itcilo.it/english/actrav/telearn/osh/ergo/ergoa.html Occupational Health Clinics for Ontario Workers Inc.: Ergonomics & Pregnancy http://www.ohcow.on.ca/resources/handbooks/ergonomics_pregnancy/Ergonomics_And_Pregnancy.pdf Workers’ Compensation Board Alberta, Office Ergonomics: Remembering the Basics http://www.wcb.ab.ca/pdfs/ergobk.pdf State of California Department of Personnel Administration, The Computer User’s Guide to an Ergonomic Workstation http://www.dpa.ca.gov/benefits/health/workcomp/pubs/CompUsersHndbk/dpahandb.pdf Laptop Computer Ergonomics http://ergoindemand.com/laptop-computer-ergonomics.htm CUErgo Cornell University Ergonomics Web http://ergo.human.cornell.edu/culaptoptips.html Ergonomics and Tips on using Laptop Computers http://web.mit.edu/atic/www/disabilities/rsi/laptopergo.html Laptop Computer Ergonomics http://www.ergoindemand.com/laptop-computer-ergonomics.htm Workplace Exercises http://www.utoronto.ca/safety/ergoweb/exercise.html Workstation Ergonomics http:// www.ithaca.edu/safety/ergonomics/stretch.htm University of Victoria Occupational Health and Safety, Nov 18th, 2003 Mailroom: Standing and Manual Material handling http://ohs.uvic.ca/ergonomics/deptspecific/mailroom/mailpresentation.pdf

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Appendix: Office Ergonomics Self-Assessment Checklist

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OFFICE ERGONOMICS SELF-ASSESSMENT CHECKLIST

This aim of this checklist is to help you identify how you use your computer and what

you can improve with your computer set-up. Part A – What type of computer user are you? What type of computer work do you do?

θ Email and correspondence

θ Spreadsheets θ Graphic θ Word processing

θ Surfing the internet θ Programming θ CAD θ Data Entry How many hours a day do you work on the computer?

θ Less than 3 θ 3-5 θ 5+ How long have you worked at this job? ___________________________________________ If less than 5 years, what positions have you held previously? _________________________ __________________________________________________________________________ Part B – Body Do you feel any discomfort? If so, where?

θ Back of neck θ Shoulders θ Lower back θ Elbows θ Forearms θ Wrists θ Fingers θ Eyes θ Thighs θ Knees θ Lower legs θ Ankles/feet

Part C – Checklist

WHAT TO LOOK FOR YES NO TIPS / POSSIBLE SOLUTIONS

Legs and Back Do you have enough legroom? Have you adjusted your chair so that: ♦ Your feet are flat on the floor or on a footrest? ♦ Your hips are slightly above your knees? ♦ The lumbar support is positioned so as to

support the curve of the lower back?

♦ There is a 1 to 4 inch gap between the edge of your seat and the back of your knees?

Don’t be afraid to try out the adjustments on your chair (back, height, tilt, armrests).

Also, sit back in your chair and tuck in your abdominal muscles

Neck and Head Have you adjusted your monitor so that the top is at or slightly below eye level?

Is the monitor directly in front of you and approximately one arm’s length away?

If you need a document holder, is it adjacent to or directly in front of the monitor?

What you look at or use the most should be placed directly in front of you

Avoid cradling the phone. Consider using a headset.

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Arms, Wrists, and Hands Can you adjust your keyboard and mouse at or slightly lower than elbow height?

Are your wrists straight while operating the keyboard and mouse (you can use wrist rests)?

Is the mouse at the same level as and next to the keyboard?

Are your shoulders relaxed while you work?

Use minimum force while striking keys.

Avoid resting elbows, forearms, wrists on sharp edges

Elbows should hang close to the body.

Eyes Is the monitor positioned so as to avoid glare or reflection?

Are the fonts and images sharp, clear and easy to read?

Is there adequate lighting?

Place monitor perpendicular to windows and use blinds to prevent glare

Try gazing at a distant object or blinking to give your eyes a break

It takes more light to read a document than for the computer

Tell your eye specialist how often you use your computer to obtain the correct prescription.

Other Ideas Do you keep often used items within easy reach?

Do you alternate tasks throughout the day?

Do you allow time for stretching and mini-pauses during the day?

Are temperature and noise levels appropriate?

If there is more than one user of this workstation, are all surfaces adjustable?

Position what you use only occasionally further away to avoid frequent over reaching.

Also keep your work area neat and tidy

Take mini-breaks from the computer by making photocopies, phone calls, etc.

Organize your workload to avoid stress

If most of your answers are yes, then you have arranged your workstation to your needs. However, if most of your responses are no, you can refer to the Tips to determine if you can make some changes and improvements to your workstation.

Comments: ______________________________________________________________________

________________________________________________________________________________

________________________________________________________________________________

If you would like to request an assessment from the Environmental Health and Safety Office, please return the completed form, along with your name and department listed below, to S-GM-1100-50 or send it by fax to 2807. Name: ___________________ Department: ______________________ Phone: ________