Computer Ergonomics

Living with computers

Dr. Charles Daniels, D.C.

Chiropractor


This page, and all contents, are copyright © 1995 and 1996, Charles F. Daniels, D.C., B.Sc. (hon.)

Table of Contents:

0. Introduction -Please read this.
1. The Human Interface - the ergonomics of computer use
2. Osteoarthritis - how to avoid joint wear and tear
3. Carpal Tunnel Syndrome - prevention of hand and wrist troubles
4. Computer Electromagnetic Radiation and Its Health Effects
5. Exercises - Some easy things you can do to feel good and prevent fatigue
6. Stress - coping with computer generated stress
7. Special Computer Concerns for Women
8. Special Computer Concerns for Children
9. How to Register -My favorite section.
10. Related books to read
11. Referral Directory Chiropractors near you who have a special interest in computer related health problems.
12. My Office A brief description of my practice facilities.


0. Introduction

Introduction


Welcome to my computer ergonomics homepage. I hope the information here can be of some help to you. The big idea is to help you be able to use you computer without health problems sneaking in to ruin your fun or decrease your productivity. The emphases is very much on preventing troubles rather than trying to fix existing conditions. Although some guidance as to what can help will be touched upon, if you have a problem, this page is no substitute for professional help.

This page is very much a work in progress. I shall continue to expand and upgrade it as time goes on. Registered users will automatically get updates E-mailed to them as they are made.

On Site Consultation: I do on site work place ergonomic consultation for heavy industry as well as office work. If you are interested, please contact me to arrange time and costs.

Dr. Charles Daniels, D.C.
Box 1260, R.R. # 1
Yarmouth, N.S., Canada
B5A 4A5
1-(902)-742-9419
cdaniels@fox.nstn.ca


Registration: I've presented a fair amount of material here for you at no charge. If you would like to obtain further information, (or if you just plain want to reward me for being such a nice guy), Please register. Registration will also entitle you to ask me questions about your own ergonomic concerns. (as best I can via E-mail without actually being at your location.)

Thank You, Dr. Charles Daniels

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1. The Human Interface

The Human Interface
Working with a video display terminal (VDT) and a keyboard can be productive, rewarding and a lot of fun. Unfortunately, prolonged postures, coupled with high levels of concentration and the occasional frustration of things going less than perfectly, can lead to physical problems. Basic understanding in the way you "interface" with your computer can help prevent common health-related VDT and keyboard problems. A little knowledge of the principles of ergonomics, how people interact safely and efficiently with machines and their work environment, can save a lot of discomfort and maximize both productivity and enjoyment.

Machine Set-up

  • Visibility.You must be able to see what you are doing easily to avoid eye strain and neck pain. Have adequate amounts of light. Florescent lights are not very good, the so called "natural spectra" florescent lights are not quite as bad, incandescent lighting is better and indirect natural (sun) light is best. Reduce glare as much as possible, not only on your screen but also on the rest of your work ares including the keyboard. Hoods, drapes, glare screens and changing the lights can do wonders. Use the control knobs on the monitor, they can help you. Don't be afraid to fiddle around with the tilt and height positions of the monitor. Rearrange things until you can see well and it feels comfortable for you.

  • Chairs. As with visibility factors, experiment with chair height and/or tilt. Try different chairs. Keep trying until you get it the way your body likes.

  • Keyboards. Be sure to get the height right to prevent too much bend at the wrist and allow the forearm to have some support. The arms should hang loose to prevent the shoulder muscles from cramping. Many keyboards can tilt; unfortunately, most of them tilt the wrong way. If any thing the keyboard should tilt to help the wrist stay straight, which is to say raising the space bar end and lowering the "top"(the F1, F2 etc.) end. Tilting the key board the other way, (space bar lower and "top" row higher) can predispose you to carpel tunnel syndrome.

  • Mouse. The continual clicking and small, precise motions involved in mouse use are a repetitive action that can be a health hazard. A few basic rules can help make handling this convenient input devise safer and more comfortable:
    1.) Hold the mouse loosely. "White knuckling" the mouse creates too much tension. Use a light touch when you click.
    2.) Use you whole arm and shoulder to move the mouse, not just your wrist. Don't rest your forearm on the desk while you move the mouse.
    3.) Do not lift your "pinkie", use all of your fingers to lightly hold the mouse.
    4.) Keep your wrist relaxed and neutral, not bent. The click button should be about the same height as your keyboard.
    5.) Avoid prolonged postures. Rotate your shoulders, gently shake your hands and fingers four or five times per hour.
    6.) Left handers should use a "left handed" mouse, or configure the mouse to work best with their different (mirror image) hand shape.

  • Desks. Make enough space so that you have room to work, especially if your pushing your mouse around. Use a paper holder to keep letters or books semi-vertical and at eye level. Your work space should be set up so that you need not twist your neck. Documents should be positioned at the same height and next to the VDT, especially if a lot of time is to be spent at these tasks. Make your work space user friendly.

  • VDT. Keep your distance. Electromagnetic radiations follows the inverse square rule, which is to say the further away you are from the source, the weaker they get and they do so quickly. You can protect yourself with space. I recommend you stay at least 75 centimeters (30 inches) from your terminal and at least one meter (40 inches) from other terminals.

  • VDT. Keep it fixed. X-ray and other radiation production increases dramatically when the VDT is damaged, improperly maintained, or just plain worn out. PCBs are sometimes released by very old VDT models (ie built before 1970).

    Human Set-Up

  • Posture. No one posture is perfect. You do not have to be "military" but getting comfortable is essential. Footrests help, (or a book or lunch pail or anything handy to rest your feet up a bit), as do cushions if your chair is not providing adequate support. The most important rule is to avoid prolonged positions. Shake your hands and shoulders now and then. Keep lose.

  • Eyes. After good lighting and avoiding glare, the most important eye consideration is to look away from the screen occasionally. It really helps. Also, don't forget to blink. Blinking moistens the eyes to prevent burning from dryness.

  • Warm up. Just as an athlete prepares for the game by stretching and loosening the joints and muscles to prevent injury and enhance performance, you too should prepare for a marathon session surfing the Net. Do some shoulder rolls, neck stretches, wrist wiggles and leg stretches before you even log in. Prevention is better than repair.

  • Breaks. If you hold any part of you in one position for longer than an hour, you set your self up for stiff joints, achy muscles, tendon fatigue and ligament weakness; not to mention decreased efficiency and diminished concentration. If you are focused on what you are doing, you can loose track of time unless you purposely schedule breaks. Have the computer clock on screen, or steal the oven timer out of your kitchen, or set the alarm on your watch, or somehow let yourself know about the passage of time. Then, at least once an hour, (every half hour would be better), get right up off your seat and walk around, stretch, yawn, wiggle, breath, get the blood flowing and stimulate the joints. It is worth the time and trouble as you will feel better, work sharper and get more done. Take advantage of un-scheduled "downtime". Instead of staring at the little hour-glass and wishing it would go faster, do something beneficial for your body.

    If you already have mechanical body problems, such as neck arthritis or carpel tunnel syndrome, it is necessary to take breaks more frequently; on the order of three or four mini-breaks per hour. Preventing a flair-up is far superior to irritating these disorders.

    More Information

    Some special health concerns beside osteoarthritis and carpel tunnel syndrome; such as circulation troubles (like varicose veins or hemorrhoids), cataracts, coccyxdynia (tail bone pain), or tension headaches, just to name a few, require additional care and consideration .

    Pregnancy, though not a health problem, does require extra concern, not only with ergonomics but also with radiation such as ELF and VLF waves.

    If you would like more detailed information about the ergonomics of working with a computer, warm ups and stretching, or computer aggravated disorders , do not hesitate to ask your Chiropractor, or if you prefer, you can contact me. Good Luck.

    Dr. Charles F. Daniels, D.C. Chiropractor
    1-902-742-9419
    E-mail: cdaniels@fox.nstn.ca



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    2. Osteoarthritis


    Osteoarthritis


    Of all the forms of arthritis, Osteoarthritis (O.A.) is, by far, the most common. It effects over 25% of Canadians and is the single most common disorder of the elderly. But to say that it is a disease of old age can be misleading, as some children have it while some lucky people in their 80's do not. Yet nearly everybody over the age of 35 has at least some trace of it; and the older you get, the greater the chances of suffering from it.

    This makes sense when we realize the nature of the disorder. O.A. is actually nothing more nor less than "wear and tear" of the joint surfaces. We are all familiar with that smooth, shiny cap of cartilage on the ends of chicken bones. That is a fine example of a healthy joint surface. If this bearing surface becomes roughened, cracked, dehydrated, abrasive, not so slick; when friction and wear occur with movement; that situation is O.A. This is what gives the stiffness and rigidity to the joints that limits the flexibility and decreases the ranges of motion. You then can feel the crepitis (a sound like hairs rubbed together between your fingers) caused by the roughness of the joint surfaces. And it aches!

    What Happens? The fact is, our joints are so perfect at birth and so good at self maintenance that they could last a century or more. And they do in many people. Nobody has O.A. in all their joints, even though all your joints are the same age, so it can not be caused purely by aging. The problem is merely cumulative stress and mechanical trauma. As we get older we accumulate more and more abuse to our joints. Falls, auto accidents, sprains and the like are obvious culprits. Indeed, severe or repeated trauma will virtually guarantee O.A. of a joint. More insidious factors such as poor posture, chronic over work, tedious, repetitious chores and prolonged postures are also hard on our joints. Some disease processes, such as diabetes, slow down the repair processes and thus speed up joint erosion. As we age our cartilages tend to dry up and become brittle. This is especially true for those of us who do not have adequate water intake. Being over-weight puts a lot more compression on the weight-bearing joints in the spine, hips and knees and feet. Poor nutrition, (not getting the adequate building blocks into our bodies to make the repairs), will also set up our joints for a faster decline. Since most joint repair is done while we sleep, insufficient amounts of sleep, or poor sleep patterns, can also contribute to premature joint wear; as will inappropriate sleeping postures, or a poor mattress or pillow. Finally, emotional factors such as worry, grief, anger, fear and impatience can cause our muscles, especially in the neck, to tighten to the point of jamming the joints together, creating greater friction and wear.

    What to do. All this O.A. is, fortunately, preventable to a large extent. Even if we are unlucky enough to have a major trauma such as an auto accident, we can still enhance the repair mechanisms in our joints and minimize the wear that aggravates the damage by following a few simple rules:

  • Adequate Rest: Eight hours is not a magic number. Get enough sleep at night, or combined with a nap so that you feel well rested.

  • Good Work Habits: Taking occasional breaks to allow your body to recover is especially important when doing unaccustomed activities. Proper lifting techniques, such as using your knees to lift instead of bending your back, can save a lot of wear and tear. Don't rush! Haste creates micro trauma to the joints, (micro trauma being little bangs and bruises, small unfelt injuries that add up over time).

  • Avoid Prolonged Postures: Moving parts want to move. Whether resting or working, holding a joint in any one position for very long leads to the formation of adhesions (sticky spots) which can damage that joints surface.

  • Proper Weight: Avoiding the extra pounds not only helps your joints stay young, but also is very good for the rest of your body especially your heart and weight bearing parts.

  • Reasonable Nutrition: Not necessarily becoming a health food nut, but eating a balanced diet. This should include some fresh vegetables and some fresh fruit every day. Also some foods that are high in protean. And don't forget water; five or six glasses a day will help a lot to prevent cartilage dehydration; as will avoiding excessive amounts of alcohol, caffeine, salt and sugar.

  • Keep In Shape: Regular, mild exercise, such as a daily walk, can keep things moving nice and smoothly.

  • Professional Help: Seeing your Chiropractor periodically for a check up to keep the joints mobile and mechanically well aligned is a great aid. Research has shown that these treatments can minimize the formation of O.A. as well as decreasing its pain and stiffness. While seeing your Chiropractor, ask for more details about what is best for you personally regarding work habits, exercise and nutrition in the prevention and management of Osteoarthritis.

    Dr. Charles F. Daniels, D.C., Chiropractor
    1-902-742-9419
    E-mail: cdaniels@fox.nstn.ca

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    3. Carpal Tunnel Syndrome


    Carpal Tunnel Syndrome


    Carpal tunnel syndrome (CTS) is a compression of the median nerve in the wrist. Symptoms include pain and numbness in the hand (especially at night), clumsiness, paresthesia (pins and needles), and trophic changes (such as muscle wasting). In a true CTS, these are felt where the median nerve goes: the palm side of the index and middle fingers and part of the thumb and ring finger. Conservative treatment without surgical intervention will usually give relief, especially if done early after onset.

    Similar symptoms can also be due to nerve compression in the neck, shoulder or arm from such things as tight neck or shoulder muscles (ie: thoracic outlet syndrome or pectoral muscle contracture) or poor neck mechanics to name a few. These other problems are often mis-diagnosed as CTS. To help see if you have a true carpal tunnel syndrome or not, use Phalen's test.

    Phalen's Test



    Place the backs of both of your hands together and hold the wrists in forced flexion for a full minute. (Stop at once if sharp pain occurs) . If this produces numbness or "pins and needles" along the thumb side half of the hand, you most likely have Median nerve entrapment (Carpal Tunnel Syndrome). Examination by a health care professional familiar with these conditions is the way to be sure of the diagnosis and get proper treatment.

    Keyboards Be sure to get the height right to prevent too much bend at the wrist and allow the forearm to have some support. The arms should hang loose to prevent the shoulder muscles from cramping. Many keyboards can tilt; unfortunately, most of them tilt the wrong way. If any thing the keyboard should tilt to help the wrist stay straight, which is to say raising the space bar end and lowering the "top"(the F1, F2 etc.) end. Tilting the key board the other way, (space bar lower and "top" row higher) can set you up for carpel tunnel syndrome.

    Treatment Effective conservative treatment of CTS should include:
  • Chiropractic manipulation of the wrist, forearm and hand
  • Ice massage (10 to 12 minutes) several times a day
  • minimizing any irritating activities
  • wrist strengthening exercises
  • wrist stretching exercises
  • possible use of wrist brace or splint while sleeping
  • applying sound ergonomic principles (see The Human Interface)

    Seeing your Chiropractor for a check up to keep the joints mobile and mechanically well aligned is a great aid. These treatments can minimize the formation of CTS as well as decreasing its pain and impact on your job and lifestyle. While seeing your Chiropractor, ask for more details about what is best for you, personally, regarding work habits, exercise and stretching to promote good health and in the prevention and /or management of carpal tunnel syndrome.

    Dr. Charles F. Daniels, D.C.
    Chiropractor
    1-902-742-9419
    E-mail: cdaniels@fox.nstn.ca

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    4. Computer Electromagnetic Radiation and Its Health Effects



    Your health may be effected by radiation given off by your computer. Computers do generate very low levels of infrared light, visible light, ultraviolet light, X-rays and electromagnetic fields. Recent studies have raised some concerns about ELF and VLF waves, PCBs, ultrasound, electrostatic fields and other emissions as well.

    Extremely low frequency (ELF) electromagnetic waves are produced by high voltage power lines, transformers, virtually everywhere electricity flows, including a VDT screen. Very low frequency (VLF) electromagnetic waves are also emitted by computers.

    Much of the current, (no pun intended), data regarding how much radiation is safe, and how safe is safe, is inconclusive or even contradictory. After much searching and due consideration, I suggesst the following prudent course of action.

    Recommendations:

  • 1. Keep your distance. Electromagnetic radiations follows the inverse square rule, which is to say the further away you are from the source, the weaker they get and they do so quickly. You can protect yourself with space. I recommend you stay at least 75 centimeters (30 inches) from your terminal and at least one meter (40 inches) from other terminals.

  • 2. Keep it fixed. X-ray production increases dramatically when the VDT is damaged, improperly maintained, or just plain worn out. PCBs are sometimes released by very old VDT models (ie built before 1970).

  • 3. Limit your time. If you have to sit at the computer for hours every day, you should seriously consider limiting how much time you spend playing video games and watching TV at home. This is most especially true if you are pregnant.

    Dr. Charles F. Daniels, D.C.
    Chiropractor
    1-902-742-9419
    E-mail: cdaniels@fox.nstn.ca

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    5. Exercises - Some easy things you can do to feel good and prevent fatigue .

    This article is available for rigistered users.

    Return to Table of Contents















    6. Stress - coping with computer generated stress.

    This article is available for rigistered users.

    Return to Table of Contents















    7. Special Computer Concerns for Women

    This article is available for rigistered users.

    Return to Table of Contents















    8. Special Computer Concerns for Children

    This article will be available for rigistered users.

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    9. Registration

    If you would like to be a registered user of this homepage, you will be entitled to:

  • All of the contents of the page.
  • Continuing updates as this page grows and expands.
  • Your questions answered concerning your specific computer ergonomic needs. (as best I can via E-mail without actually being at your location.)

    Costs: Twenty dollars ($20.00) in United States funds.
    Canadians: Twenty Canadian dollars. (includes G.S.T.)

    Mail cheque or money order to:
    Dr. Charles Daniels, D.C.
    Box 1260, R.R.#1
    Yarmouth, N.S., Canada
    B5A 4A5

    Please include your E-mail address and I will send you the file (HTML), or include a disk and I will snail mail it to you. Thank you.

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    10. Related books to read (under construction)
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    11. Referral Directory
    Chiropractors near you who have a special interest in computer related health problems:



    Dr. Charles Daniels, D.C.


    Yarmouth
    Chiropractic
    Clinic
    New Patients are Welcome. No Referral Necessary.



    Location:
    Box 1260, RR #1
    Yarmouth, N.S. B5A 4A5
    Canada
    In the village of Hebron, a short drive outside Yarmouth on Highway # 1
    Phone: (902) 742-9419
    Business Hours:
    Monday 10:00 8:00
    Tuesday 10:00 4:00
    Wednesday On Call
    Thursday 10:00 8:00
    Friday 10:00 4:00
    Saturday 10:00 2:00
    Sunday On Call
    Holidays On Call





    Dr. Patrick Milroy, D.C.


    Spring Garden
    Chiropractic
    New Patients are Welcome. No Referral Necessary.



    Main Office:
    Halifax Professional Center #460
    5991 Spring Garden Road
    Halifax NS B3H 1Y6
    Canada
    Phone: (902) 429-3443
    Fax: (902) 429-8338
    Business Hours:
    Monday 11:00 6:00
    Tuesday 11:00 6:00
    Wednesday 11:00 6:00
    Thursday 11:00 6:00
    Friday 11:00 6:00
    Saturday On Call
    Sunday On Call
    Holidays Closed



    If you are a chiropractor and would like to find out how to be added to this directory, E-Mail me at:
    cdaniels@fox.nstn.ca

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    12. My Office


    Yarmouth
    Chiropractic
    Clinic
    New Patients are Welcome! No Referral Necessary!



    Location:
    Box 1260, RR #1
    Yarmouth, N.S. B5A 4A5
    Canada
    In the village of Hebron, a short drive outside Yarmouth on Highway # 1
    Phone: (902) 742-9419
    Business Hours:
    Monday 10:00 8:00
    Tuesday 10:00 4:00
    Wednesday On Call
    Thursday 10:00 8:00
    Friday 10:00 4:00
    Saturday 10:00 2:00
    Sunday On Call
    Holidays On Call
    The greatest compliment our patients can give is the referral of their friends and loved ones. We strive to earn that trust.


    Products and Services:
    • Diversified Chiropractic technique
    • Ergonomic Consulting
    • Ultrasound and electrical modalities
    • Custom foot orthotic inserts
    • Cervical pillows and collars
    • Workers' Compensation Cases
    • Nutrition, Lifestyle and Injury Prevention Counselling
    • Over 15 years of clinical experience



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    Questions, problems or suggestions? Contact :

    Dr. Charles Daniels, D.C.
    Box 1260, R.R. # 1
    Yarmouth, N.S., Canada
    B5A 4A5
    1-(902)-742-9419
    cdaniels@fox.nstn.ca