ergonomic handbook 6-09

8/7/2019 Ergonomic Handbook 6-09

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Computer

Workstation

Ergonomic Handbook

County of Fresno

Personnel Services- Risk Management

Revised December 1999

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ACKNOWLEDGMENTS

We are grateful to the following County and State Agencies, and private corporations for their

assistance in the development of this handbook:

The County of Fresno's Sheriff's Department

The California Department of Water ResourcesThe California Department of Toxic Substances Control

The Fresno Bee

Hewlett Packard

USAA Insurance Company

Special thanks to Kim Haisch, student intern of Golden State University, for compiling this

valuable resource for the State of California and ultimately the County of Fresno.

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PURPOSE

It is the County of Fresno's policy to provide its employees with a safe and healthy

workplace. This handbook reflects General Industry Safety guidelines for safe

workstation arrangements for employees who work at Video Display Terminals(VDTs). The purpose of this guide is to:

To educate employees that they share in the responsibility for their comfortand prevention of injury.

To increase awareness of how poor work habits and improper posturecontribute to muscular discomfort and potential injury.

To provide employees with guides and checklist to enable them to arrangeand adjust their workstation equipment safely, comfortably and according toestablished guidelines.

To provide employees with exercises that address common VDTworkstation complaints and should help to reduce workstation related

injuries.

AUTHORITY

The legal/regulatory authority for these guidelines is based on:

Labor Codes 142.3, 6357, 6400, 6401,6401.7

Title 8, California Code of Regulations,Section 3203, Injury and Illness Prevention Program

Section Section 5110, Repetitive Motion Injuries

American National Standards for Human Factors Engineering of VisualDisplay Work Terminal Workstations (ANSI/HFS 100-1988)

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INTRODUCTION

The computer workstation with the Video Display Terminal (VDT) has

revolutionized the workplace. It plays a major role in increasing individual andorganizational productivity and efficiency.

Just as the computer has changed the way many people work, it is becoming

increasingly necessary for users to change the way they interact with them. With

the increase in the number of injuries that have resulted from work at computer

workstations, the County of Fresno has developed this handbook to help enable

employees to work more comfortably and to reduce the potential for injury.

Ergonomicsconsiders the physical capacities and limits of the employee as he or

she interacts with tools, equipment, work methods, job functions and the physical-working environment. By applying ergonomic principles, we can arrive at the best

possible fit between our employees, the equipment they use and the work they are

required to perform.

Proper workstation use, including proper posture and reasonable equipment

adjustments, with attention to muscle and eye fatigue, will help prevent

musculoskeletal and visual problems.

It is every supervisor's responsibility to ensure all employees understand andfollow these guidelines. Employees are responsible for adjusting their

workstations and their work habits to prevent injury.

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CHAIR & WORKSTATION GUIDELINES

Adjusting Your Chair and Workstation

* Adjust the lumbar (lower back) support by moving the back rest up or down

to match the inward curve of your spine.

* Adjust the tilt of the backrest and/or seat to keep your body supported in an

upright position.

* Adjust the seat height for adequate leg clearance under the workstation and

keep the keyboard at approximately elbow level.

* Adjust the monitor so the top of the screen is at or just below eye level and

ensure a viewing distance of between 18 and 24 inches.

* Use a document holder that places documents at the same height and

distance as the monitor. Note: Periodically reassess and adjust your body posture.

Source: Hewlett Packard

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PROPER BODY POSTUREAdjusting Your Body Posture

* Keep your head in line with your shoulders and hips.

* Keep your elbows close to your body.

* Keep your wrists in a neutral position, bent no more than 10 degrees up or

down.

* Keep your knees at the same level as your hips or slightly higher.

* Keep your feet flat on the floor or supported by a footrest.

* A keyboard tray for fixed work surfaces and padded wrist rests can be used

to help support the wrists in a neutral position.

* Keep fingers in a relaxed position when working.

Avoid extreme finger extensions.

Note: Periodically reassess and adjust your body posture.Source: Hewlett Packard

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WORK MATERIALS

A well-organized and properly arranged workstation can help prevent muscle

strain while improving efficiency.

* If you frequently use a telephone while at your computer, consider using a

headset or a "hands-free" telephone. Cradling a receiver on your shoulder

contributes to muscle strain and nerve damage.

* Source documents should be at the same height, angle, and distance from

your eyes as the computer screen to avoid repeated head turning and

frequent refocusing. A document holder can be attached to the side of the

monitor to keep documents next to the screen and provide additional desk

space.

* Keep frequently used materials within easy reach, within 14 to 18 inches.

* Clear the floor under your workstation so you can move your feet.

LIGHTING

Glare is the reflection on your screen that makes it hard to see the screen clearly.

Glare can be caused by sunlight on your screen, or by inside light, such as

overhead fluorescent lights and/or task lamps. Simple lighting adjustments can

help minimize glare and reduce or eliminate eyestrain and headaches.

* Position the screen so it is at a right angle to the window producing the

glare.

* Close shades, curtains, or blinds if necessary, as light changes during the

day.

* Tilt the VDT screen down slightly to avoid overhead light from producing

glare.

* If possible, sit with ceiling lights to the side, rather than directly overhead.

* If you use a task lamp, position it to aim the light at your document instead

of your screen.

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* To improve your viewing comfort, you may also need to adjust your

display's contrast and brightness controls.

* Periodically clean your screen to maximize clarity. Characters on the

screen should be clear, stable, and free from perceptible flicker.

* Consider attaching an anti-glare apparatus to the VDT if you are unable

to eliminate glare by other means.

VISION CARE

Viewing a computer monitor for long periods can cause visual fatigue and

eyestrain. Symptoms of visual fatigue are eye irritation, burning or pain, blurring

of vision, and double images. Preventive measures should be taken to ensure

correct vision for this type of work.

* The National Institute for Occupational Safety and Health (NIOSH)

recommends employees have periodic eye examinations. Eye exams are

covered under the County of Fresno health plans.

* A licensed optometrist or ophthalmologist who is familiar with the visual

demands of VDT work should perform eye exams.

* Contact lens wearers should blink often to prevent their eyes from becoming

dry.

* Frequent eye breaks are necessary during the workday.

* Periodically focusing on an object at least twenty feet away will give your

eyes a rest.

REPETITIVE MOTION INJURIES (RMIs)

Repetitive Motion Injuries (RMIs) are caused by repeated motions and exertions.

The arms and hands are especially vulnerable. The disorders can involve nerves,

blood vessels or tendons, which connect muscles to bones.

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RMI SYMPTOMS

* Swollen feeling of the fingers, yet no physical evidence of swelling

* Numbness in the thumb or hand

* Tingling in the thumb or hand

* Pain in the fingers or hand

* Weakness in hand or arm

* Burning sensation in the hand or arm

* Weakening of the muscle at the base of the thumb

* Dry, shiny palms and clumsiness of the affected hand

* Changes in sensation and power to squeeze things

Your workstation should be re-evaluated by you and your supervisor for proper

work habits, workstation adjustments, and body posture if you are experiencing

any of these symptoms. Risk Management is also available to provide assistance if

the problems persist.

TYPES OF RMIs

* Carpal tunnel syndrome: A nerve disorder resulting from entrapment of the

median nerve where it passes from the forearm through the carpal tunnel inthe wrist and into the hand. When irritated, the sheaths that surround the

tendons in the narrow tunnel can swell and press against the nerve.

Symptoms include pain, numbness and tingling in the first three fingers and

the base of the thumb. The symptoms often are worse at night.

* Tendinitis: Inflammation of a tendon from repeated tensing. With further

exertion, some of the fibers that make up the tendon can fray or tear, and the

tendon may become thick and bumpy. Without rest and sufficient time for

healing, the tendon may be permanently weakened.

* Tenosynovitis: Inflammation of a tendon and its enveloping sheath.

Repeated motions may stimulate the sheath to produce excess fluid, which

accumulates and exerts pressure on the tendon and causes pain.

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*Thoracic outlet syndrome: Compression of the nerves and blood vessels

between the neck and shoulder. Symptoms include numbness in the

fingers and tingling in the arm.

* Ulnar neuritis:A nerve inflammation that results from pressure on the

ulnar nerve over time, including leaning on the elbow on hard or sharp

surfaces for long periods. Symptoms include tingling and numbness in the

small and ring fingers.

Reporting Injuries/Illnesses

If you suffer from any of the symptoms of an RMI that you think may be work

related, report it to your supervisor.

RADIATION CONCERNS

Like other common electrical devices (irons, toasters, TVs, fluorescent lights),

VDTs can produce some kinds of radiation. Currently there is no occupational

exposure standard specifically for VDTs within the United States.

* Both the National Institute for Occupational Safety and Health (NIOSH) and

the U.S. Food and Drug Administration studies agree VDTs emit little or noharmful radiation under normal operating conditions.

* All measurements of radiation emissions from VDTs are far below the

National Occupation Exposure Guidelines and Standards for radiation.

* Presently, there do not appear to be any exposures that would put VDT users

at risk for reproductive health problems.

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WORK HABITS

Even the best posture and the most ergonomically correct workstation won't

prevent muscular stress and fatigue if you sit for several hours in one position.

Breaks from VDT work can help keep your eyes, mind, and body refreshed andenergized.

* NIOSH recommends taking a short break every couple of hours of

uninterrupted computer work. (Check with your supervisor for your break

schedule.)

* Experts also suggest brief, frequent "micro-breaks." These breaks are

defined as time spent doing something other than work on a computer. They

don't involve leaving your workstation. Suggestions include moving around,

stretching, doing non-computer tasks, refocusing your eyes, etc.

Note: The timing of such micro-breaks is more important than the duration. To be

most effective, a break should be taken prior to the onset of fatigue, rather than a

means of recuperating from it.

GENERAL BENEFITS OF EXERCISE

* Increased circulation

* Increased alertness and concentration

* Improved posture by increasing body awareness

* Improved potential to prevent and/or eliminate muscle and joint pain

* Improved potential to prevent RMIs

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EYE EXERCISESCup Them

* Lean your elbows on your desk.

* Cup your hands and place them lightly over your closed eyes.

* Hold for a minute, while simultaneously breathing deeply in and out.

* Slowly uncover your eyes.

Roll Them

* Close your eyes and slowly roll your eyeballs clockwise all the way around.Repeat this three times.

* Slowly roll them all the way around counter-clockwise. Repeat this step

three times.

* Slowly open your eyes away from a direct source of light.

Look Away

* Every 1/2-hour, look away from the computer screen.

* Focus on an object at least twenty feet away.

Look back at the screen, then look away and focus again. Repeat this threetimes.

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FREQUENTLY ASKED QUESTIONS AND ANSWERS

Q: What other activities, in addition to VDT work, can cause RMIs?

A: Any activity that requires the body to remain in the same position and repeat

the same mechanical motion many times. For example: work, such as

removing large numbers of staples, chopping, and mechanical work;

hobbies, such as gardening, needle work, and making jewelry; and sports,

such as tennis, racquetball, golf, baseball.

Q: How can I prevent RMIs?

A: RMIs can be prevented and/or minimized by taking rest breaks and using

proper stretching exercises. You should set up your work area and develop

habits that create the least amount of resistance to your muscles, nerves andtendons.

Q: What ergonomic equipment can an employer provide?

A: Within financial constraints, an employer can provide:

* Adjustable workstations or modular furniture with separate

components,

such as: monitor stands, keyboard trays, and document holders

* Ergonomically designed chairs

* Wrist rests for the keyboard and mouse

* Mouse pads

* VDT anti-glare screens and hoods

Q: What can I use to adjust my workstation in the absence of proper

accessories?

A: Wedged objects, such as binders can be used for a footrest; binders can also

be used for a document holder with binder clips to hold the sourcedocuments; stable objects can be used to raise monitors and keyboards; a

rolled towel can be used for a wrist rest, as long as it places the wrist in the

proper position; and a rolled towel may also be used as a lumbar support.

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FREQUENTLY ASKED QUESTIONS AND ANSWERS

(Continued)

Q: Who can perform workstation evaluations?

A: Your Department Safety Coordinator and/or your functional area/immediate

supervisor using these guidelines and the checklist at the end of this

handbook.

Q: What should I do if I have tried everything in these guidelines and I still

have RMI symptoms?

A: Discuss the specific problems with your supervisor and your Department

Safety Coordinator. If the problems persist, contact the Risk Management

Division at 488-3360 for assistance.

Q: What non-occupational factors contribute to RMIs?

A: The following non-occupational factors contribute to RMIs:

* Systemic diseases

* Congenital defects

* Acute trauma

* Pregnancy, oral contraceptives, menopause, and gynecological

surgery

* Vitamin B-6 deficiency

* Wrist size, shape, and strength

Q: Can carpal tunnel syndrome recur?

A: Yes, if you return to unsafe workstations, unsafe work practices, and/or

unsafe sports activities.

Q: Where can I get additional information on ergonomics and RMIs?

A: A Safety Specialist at the Risk Management Division or your Department

Safety Coordinator. There are also several publications on the subject

available through the library systems. A partial list is included at the end of

this handbook.

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WORKSTATION CHECKLIST

(A checkmark next to an item indicates the appropriate action was taken)

Chairs

______ 1. Sit firmly back in chair.

______ 2. Adjust the chair height so the thighs are parallel to the floor and the feet (heels)

are flat on the floor. Use a footrest, if necessary.

______ 3. Adjust the height of the back of the chair to fit comfortably against the curvature

of the spine.

______ 4. Adjust the slant of the back of the chair to provide support for an upright relaxed

posture. Use a lumbar support device, if necessary.

Work Surface Height

______ 5. Make sure the chair has been adjusted properly.

______ 6. Sitting in neutral position, relax shoulders and arms and allow them to "hang" as

they would when standing.

______ 7. Bend at the elbow and keep wrists in a straight, neutral position.

______ 8 Take measurements from the floor to the bottom of the palm. This distance

should be the desk height measured to the top of the work surface. Proper work

surface height for reading/writing may be one-to-two inches higher than that for

keyboard typing.

______ 9 Contact your supervisor if furniture adjustments need to be made.

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WORKSTATION CHECKLIST

(Continued)Organize Work Areas

______ 10. Place most commonly used items, e.g. overhead bins, computer keyboard,

monitor, telephone, adding machine, calendar, within easy reach.

______ 11. Place overhead/hanging bins as close as possible. DO NOT reach for and remove

large binders from bins while seated.

______ 12. Turn to face work materials. DO NOT TWIST YOUR TORSO OR TRUNK

while reaching for items.

______ 13. Put all frequently used files within close reach.

______ 14. DO NOT put the computer (monitor or keyboard) in a corner unless the desk

corner is specifically designed for a computer. Corner placement presents the

following problems by placing:

* - the monitor too far away from the eyes,

* - elbows on corners, thereby bending one's wrists,

* - and the keyboard across corners, which promotes uneven wrist pressure.

______ 15. Pull the keyboard to the desk edge and keep it flat. If a wrist rest is used, it

should be flush with the desk edge.

______ 16. Do not use the heel of the hand on the keyboard or work surface.

______ 17. Use a light touch with the keyboard.

______ 18 Applications should promote a relaxed hand position on the keyboard

______ 19. Place the monitor screen 18-to-24 inches away.

______ 20. The height of the monitor should be so the top of the screen is at or slightly below

eye level when sitting at the keyboard. The top of the screen should not be above

eye level.

______ 21. Position the screen to minimize glare from various light sources.

______ 22. Clean the screen regularly.

______ 23. Use a document holder, if necessary.

Telephone

______ 24. Place the telephone on the desktop closest to where you work the most frequently.

______ 25. Use a headset if extended phone time is required. If a headset is not feasible,

ensure your neck is not stretched in one direction for extended periods; switch

sides, reposition yourself, etc.

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SOURCES

VDT Ergonomics: Arranging Your Workstation To Fit You, Krames Communications, 1993.

VDT Ergonomics: Exercises At Your Workstation, Krames Communications, 1993.

About Working With VDTs, Channing L. Bete Co., Inc., 1986.

Working Safely With Video Display Terminals, U.S. Department of Labor, Occupational Safetyand Health Administration (OSHA), 1986.

Working With VDTs: The Human Interface, Krames Communications, 1984.

CAL OSHAs Four Step Program for Employers with Video Display Terminal (VDT) Operators,

1998.

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NOTES

VDT Handbook

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ergonomic handbook 6-09

Documents