Ladybug Electronics - Ergonomics for Computer Users

Ergonomics 101
There are many aspects to ergonomic computer use. This page deals with several issues, including keyboard types, keyboard placement, workstation flexibility, and monitor setup. You can also click on the links below to read back issues of our ergonomic newsletter.
(View Newsletter on Ergonomic Stretches, Dec. 2003, size 1.16MB)
(View Newsletter on Adjusting an Ergonomic Chair, Jan. 2004, size 735K)

Why care about ergonomic setup
As a user, the effects of poor ergonomic use and setup can become severe. Injuries to nerves, muscles, tendons, ligaments or joints add up over months or years. If not addressed early, such "cumulative trauma disorders" or "repetitive stress injuries" can cause permanent disability. Carpal Tunnel Syndrome, Tendonitis of the arm, wrist, or hand; neck-tension syndrome; headaches and even back problems can all result from poor ergonomic setup. As an employer, proper workstation setup and training will reduce lost workdays. Always remember a healthy employee is a productive employee.

Theories of ergonomic setup
The literature points to two major areas of consideration when designing an ergonomic work environment. The first is to avoid working in an awkward position and the second is to vary the positions worked regularly. When working on the computer, people should not need to stretch, reach, lean forward, crane their neck, or otherwise contort their body to fit the workstation. Much of ergonomic design is based on bringing the body into a neutral position where muscles and limbs are not stretched or twisted out of a natural rest position. By allowing the body to assume a natural position, ergonomic equipment and setup helps prevent muscle strain and soreness. Doing something the same way over and over again causes repetitive stress injuries, so the simple solution to avoiding these injuries is to reduce the repetition by varying the positions worked in. Regular breaks, exercises, and stretching also give muscles and joints a break and allow the body to rest and heal. By adjusting chairs, keyboard trays, and workstation setup slightly, different muscles come into play and tired muscles get a break.

Keyboard placement
Keyboards should be placed so a user can perform keying comfortably in a relaxed upright position.

The keying should be at approximately elbow level with forearms, wrists, and hands in a straight line approximately parallel to the floor.
Shoulders should be in a relaxed position, not elevated, and arms should rest close to the sides of the body, not extended outward or stretched forward.
The keyboard should be positioned so that keying is done with the wrist, hands, knuckles, and fingers in a relaxed, natural position. The best setup avoids pronation (rotation of the hand from a neutral, more or less vertical position to lie flat on the horizontal), deviation (twisting the wrist to align with the keyboard) and extension (either pulling the wrist up from neutral to reach a keyboard set with the back higher than the front or extending the wrist down from neutral to reach a keyboard set with the back too low)
Keep your mouse positioned close to your keyboard so you don't have to stretch to reach the mouse.
Keyboard types
Traditional Keyboard The most commonly used type of keyboard, the 101-key "traditional" version is often included when you purchase a computer. (Some models improve upon the basic version by adding special "function keys" that can group keystrokes and reduce the amount of typing necessary.)
Split-Design Keyboards(Fixed- Angle)
Split keyboards are what people most commonly think of when they hear the term "ergonomic keyboard". These keyboards divide the letter keys into two halves, and angle each half slightly outwards. The premise is that this is a more natural position for your wrists and forearms (pointing inward, without requiring your elbows to come in as far) thus better conforming to the contours of your body - especially for people with broad chests. Click here see some products available throught Ladybug.

Split Design Keyboards (Adjustable- Angle)
Adjustable-angle split keyboards are similar to fixed-angle, with the advantage that the angle between the two halves can be changed and sometimes the two halves can be physically separated. This allows you to position each half wherever your wrists most naturally rest - or place each half on specially designed trays attached to each armrest. (Some people even arrange them vertically, and position their wrists as if shaking someone's hand.). Split-angle designs often also allow you to change the slope (tent) of the keyboard. Click here see some products available throught Ladybug.

Contoured Keyboards
Contoured keyboards are sculpted to fit the hand; they place the keys in recessed curves that more closely match the natural position of the fingers. This reduces the distance your fingers have to travel when striking keys. These keyboards don't feature quite the same layout as traditional keyboards - some keys are rearranged to be operated by the thumb, since it's stronger than the other fingers. Click here to see some products available through Ladybug.

Chording Keyboards
Chording keyboards use fewer keys than traditional keyboards, and are operated by using combinations of keys instead of individual keystrokes. This reduces the total number of keystrokes and - since your fingers generally stay on the same keys - the amount your fingers or hands must move (this helps reduce the repetition that can lead to Repetitive Stress Injuries.) Since this is a "non-traditional" layout, it takes time to learn- and efficiency (even after training) is often slightly worse than with other layouts.

Dvorak Layout
Dvorak designs rearrange the key layout so that the most commonly used letters are positioned directly under a user's strongest fingers - and in the "home" row. This improves typing efficiency, but as with all alternative layouts, takes time to learn.
Workstation Flexibility
The workstation - generally the desk and chair - where the computer is used is often as important as the computer equipment itself.

The chair and desk should be adjustable for the user and by the user without special tools. It is generally good for the user to make small adjustments several times a day to exercise different muscles during the day. Here are some guidelines for workstation setup.

Chair seat and backrest support comfortable postures and permit occasional variation in the seating.
Seat height allows the user to comfortably place the entire sole of the foot flat on the floor or on a footrest.
Seat does not push against the back of the lower leg behind the knee.
Seat angle allows the operator to comfortably position the thighs approximately parallel to the floor and lower leg approximately perpendicular to the floor.
Chair back is at least 12 inches wide. Chair provides ample support for the lower back.
Arm rests, if available, allow the user to comfortably

Relax the shoulders and arms in a position close to the body.
Operate the keyboard with the home row at approximately elbow height and hands, wrists, and forearms in a straight line approximately parallel to the floor.
Move as close as desired to the keyboard
Easily reach primary work materials and accessories.

The work surface is high enough underneath so that it doesn't contact the top of the user's leg.
Work surface is large enough to hold all primary work materials and input devices such as keyboard, mouse, and trackball.
The work surface allows the users to comfortably use the keyboard, monitor, and work material. This may require a keyboard tray, monitor stand, or split work surface.
Monitor Setup
There are three important variables to consider when setting up a monitor. The first is placement relative to the user, the second is proper lighting to avoid glare, and the third is proper adjustment of the monitor and computer.

The monitor should be placed at a good reading distance and comfortable height for the user.

The monitor should be placed at a distance that the user could comfortably view the screen and read at. The screen resolution and font size selected will have a tremendous effect on the comfortable reading distance and can be adjusted at the operating system and program levels. Comfortable reading distance is usually somewhere more than one foot and less than two feet away. LCD screens do not have the electromagnetic radiation issues that CRT screens do and the manufacturer's recommendation for the minimum viewing distance should be observed.

The topmost viewing area should be slightly below eye level when the user is viewing in a natural upright position. The user should not have to crane the neck forward or tilt the head back or too far down to view the screen. Many monitors have a height adjustment or can be placed on a stand, book, or adjustable monitor arm to raise the height if needed.
The monitor should have adequate background lighting so as not to be a source of glare and should be placed out of direct light so as not to be subject to glare. Here are some possible changes that could be made to reduce glare.

Use blinds or curtains over windows that create glare.
Position VDT operator and monitor so that direct light is not in the operator's eyes or reflected on the monitor.
Position monitor screen to be at a right angle to windows that create glare.
Install a dimmer switch and/or remove some light bulbs.
Turn-off some overhead light and use task lighting, if needed.
Use glare screen.
The monitor and computer both have several adjustments that should be set in order to reduce eyestrain.

The monitor's adjustments include the brightness level, contrast level, and color.
The monitor's factory presets may be great in average lighting conditions. However, if a glare screen is used or unusual lighting conditions exist, the monitor's
settings should be changed. After taking steps to reduce glare, adjust the brightness and contrast so the screen can be comfortably read.
The operating system also provides control over the screen resolution, icon size, font size, and refresh rate. When possible, use the resolution and refresh rate that matches your video monitor. If the monitor supports multiple settings, choose the highest refresh rate and a comfortable resolution. When using higher resolutions, adjust to a larger font and icon size so a user does not have to strain to read the screen. If the user still has trouble reading the screen, reduce the resolution.
In some cases, a monitor may have ghosting or a fuzzy display caused by interference. A sharper image can sometimes be obtained by upgrading to a shielded cable.
Much of this page is based on information from www.healthycomputing.com and CalOSHA's Four Step Ergonomics Program for Employers with Video Display Terminal (VDT) Operators. Thank you to Dr. Tony Tropea of The Chiropractic Sports Center who reviewed this article. You can get more ergonomic information at www.chirosportscenter.com/Ergonomics.html.