Reprinted from The RSI Network - Issue 31 - September'98
Scott Wright, MS-HF&E
Editor, The RSI Network
Ergonomic theory instructs computer users to type with their hands floating over the
keyboard, like trained, disciplined typists. However, many of us were never trained to do
so and have developed lazy habits that allow our wrists to sag to the table surface while
typing. This forces the wrists to bend upward in hyperextension, which strains the forearm
muscles and exerts pressure on the nerve and tendons that run through the wrist. Over
time, this can cause swelling, discomfort, and injury. A second issue concerning resting
ones wrists on the table is that its hard surface and sharp edge press against the
bottom of the wrists and can compress the soft tissues of the hand, adversely affecting
the nerves and blood vessels.
Stationary Wrist Rests
A wrist rest typically is a raised strip of cushioning that fits in front of a keyboard
or pointing device (mouse, trackball, etc.). Wrist rests come in varying shapes, padding
materials and types of covers, which will determine how comfortable they are to use and
their effectiveness. Wrist rests should be well padded, with no sharp edges, and provide a
soft support that conforms to the wrist and palm heel. The height of the wrist rest should
be at about the same level as the computer keyboard's front edge or spacebar (this is
typically 3/4 to 1 inch for modern, low-profile keyboards). Keyboard wrist rests usually
are around 20 inches in length, and some are as wide as 28-30 inches to cover the pointing
device as well.
The primary purposes of a wrist rest are to keep our wrists in a straight (not flexed
or extended) posture at the keyboard, provide a softer surface to rest on, and help
support the weight of our arms. Wrist rests should be used as a guide to keep our wrists
straight and provide a soft place to rest between periods of typing. Avoid pressing into
or leaning on the wrist rest, pinning the wrist into the wrist rest while typing, and
depending on your wrist and fingers to do gymnastic feats reaching all the keys. Your
whole arm, starting at the shoulder, should be used to reach for keys far from the home
row.
Moving Wrist Gliders and Supports
There are also several different products for the wrist and arm that rest on the table
and move with the arm during mouse use. These products provide continuous support while
pointing (sometimes keying) and can help in relieving shoulder discomfort. However, you
should not lean or put excessive force on them. These mobile palm supports can be a better
choice, as they move with you instead of being something to drag your arm across, or over,
while using a mouse or a trackball. Below is a sampling of products of this type:
aergonomic's Wrist Rest ($6.00/pair)
Applied Ergonomic Research, (800) 640-1786, http://www.aergonomics.com
aergonomic Wrist Rest arm supports are mobile, air-cushioned pads that support your arms,
allowing you to relax while you key. These are small, puck-shaped supports that glide with
you during keyboard and mouse use.
Comfort Point ($24.95 ea.)
AliMed, (800) 225-2610, http://www.alimed.com
Comfort Point lets you control a mouse or trackball with your fingers and arm, not your
wrist. An ergonomically contoured, ultrasoft paddle supports both wrist and palm, and can
be adjusted at negative, positive, and neutral angles to cradle and support your wrist.
Glides smoothly with mouse for continuous support. Mac and PC mouse and trackball
compatible.
Ergowrist ($9.95 ea.)
Ergolink Ltd., (800) 990-9319, http://www.ergowrist.com
Ergowrist is movable to allow arm-control of the mouse. Its autopositioning includes a
flexible, spring-loaded tether that connects to the mouse, allowing the Ergowrist to park
behind the mouse when you remove your hand. The tether is sensitive to allow finger
control.
Ergowrist Palm ($19.95 ea.)
Ergolink Ltd., (800) 990-9319, http://www.ergowrist.com
Ergowrist Palm is a movable hand pad that supports the weight of your palm on an
adjustable, elevated platform to allow your hand to relax in its natural, arched posture,
without interfering with arm or finger control of the mouse. (May not work well with
highly contoured mice.)
Launch Pad ($49.95 Std., $69.95 Pro.)
ErgoSpace Corporation, (206) 739-8880, http://www.ergospace.com
The Launch Pad uses a stationary, saddle-like, contoured palm cushion that is suspended
over the front edge of its mouse pad. The black "SureTrak" mouse pad has a
special surface that promotes accurate tracking and can actually clean debris off of mice
tracking balls.
Mouse Nest ($23.95 ea.)
AliMed, (800) 225-2610, http://www.alimed.com
The Mouse Nest glides with the mouse, completely supporting the hand in a natural, neutral
position. Its contoured surface helps the hand "grip" the Mouse Nest for easy
maneuverability, eliminating excess finger gripping and wrist tension.
Palm Glider ($49.95 Std., $69.95 Pro.)
ErgoSpace Corporation, (206) 739-8880, http://www.ergospace.com
The Palm Glider uses the same foam saddle as the Launch Pad, but moves with the mouse to
allow both arm and finger movement. It looks a little like a mouse chariot, as the mouse
is attached to the Palm Glider by strips of velcro.
PowerPaw ($24.95 ea.)
MedExcel, Inc., (800) 335-PAWS (7297), http://www.powerpaw.com
The PowerPaw protects the soft-tissue areas of the wrist and forearm and may help to
reduce the pressures associated with such repetitive strain injuries as carpal tunnel
syndrome. Based on advanced gel and polymer technology, the PowerPaw provides flexible,
mobile support, while the rounded contours adapt to any user position. The PowerPaws
gliding base allows effortless and continuous freedom of motion.
Wrist-mice ($29.95 pair)
AliMed, (800) 225-2610, http://www.alimed.com
A pair of Wrist-mice support each wrist in angled, padded cradles, letting your wrists
slide along the table from keyboard to mouse in an easy, unrestricted gliding motion.
Wearable Forearm Supports
The following two products attach to your forearm(s) to provide support that stays with
you at the keyboard, pointing device, and/or calculator. Note: If your keyboard is at the
front edge of the table or support surface, these devices have no surface to rest on.
The WristThotic ($7.50 ea.)
WristThotic, 1-888-565-9101, http://www.wristthotic.com
The WristThotic is an inflatable ergonomic product made of light-weight vinyl with a
comfortable, nonallergenic cloth backing. It attaches with velcro straps to the forearm,
near the wrist, and is designed to elevate and support the wrist on a cushioning air bed
approximately one inch above the desk surface.
MOPAD ($35.00 ea.)
AliMed, (800) 225-2610, http://www.alimed.com
Mopad is a contoured, foam cushion that supports, elevates, and protects the area from
wrist to elbow. It is covered with a slippery fabric that glides across the work surface,
and attaches to your wrist with an elastic strap, so it moves with you.l
Related Website Resources
Typing Injury FAQ - Wrist Rests (more descriptions and photos of products)
http://www.tifaq.org/accessories/wristrests.html
Pros and Cons of Various "Ergonomic" Office Equipment
http://www.ur-net.com/office-ergo/pros&.htm#Wrist Rests
IBM Healthy Computing - Palm Rests
http://www.pc.ibm.com/us/healthycomputing/palmrest.html
AliMed - Wrist Rests: Why Important
http://www.alimed.com/cgi-bin/why.cgi?page=e111
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