Sean Chen, Alan Hedge, and Dwight Owsen
- The key to good ergonomics, the science of adapting physical
devices to the human body, is to match the design of the technology
to the needs and characteristics of the user. Identifying
what type of keyboard is best suited for an individual based
on her specific needs should be left for physical therapists
keyboards discussed below use different physical designs
to improve typing safety and performance. Some keyboards
were specifically designed for people injured by traditional
keyboard formats or for those with a physical disability
that affects their typing ability, such as a one-handed
typist. Other keyboards are designed for the general user.
keyboards are more expensive than conventional ones, but
this may change as they become more widespread. Most designs
offer some health benefits by reducing injury risk factors.
Moreover, many designs result in demonstrable productivity
improvements, with users improving their overall work speed
by up to 80%. These benefits might soon outweigh the initial
costs of ergonomic designs.
effective ergonomic design must meet the following criteria:
It must fit the job to be done and enhance work performance,
in terms of either the quantity or the quality of work.
must fit the user in terms of its size and physical shape.
It must protect the user against injury.
It must be comfortable and easy to use.
Development of Ergonomic Keyboards
the late 1930s, researcher August Dvorak improved the standard
layout of the alphanumeric keys by developing an alternative
layout to the familiar QWERTY (derived from the first six
letters on the third row of keys) keyboard layout that most
people use today. Unlike QWERTY, the DVORAK layout allows
typists to type more than twice as many words from the home
row keys, which, theoretically, should greatly improve typing
the 1970s, all computers sold in the U.S. support both QWERTY
and DVORAK keyboard layouts. Despite more than a half-century
of research and debate about the advantages of the DVORAK
layout, the QWERTY layout has remained the de facto keyboard
and, despite its limitations, most users seem to accept
this now familiar layout. A recent study by the National
Institute of Occupational Safety and Health compared the
two layouts and failed to find any performance or postural
benefits with DVORAK.
the mid 1960s, there have been numerous other redesigns
of the computer keyboard. Today several varieties of “ergonomic”
keyboards are available. All offer some benefits to some
users, but each has limitations. Apart from the conventional
keyboard, none of these designs has gained widespread acceptance.
keyboards have evolved substantially over the past 20 years
as well. Keyboards have become flatter; function keys are
now on a top row; key mechanisms have become “lighter,”
requiring less force; and most keyboards have a cursor keypad
and a numeric keypad. Thus, most ergonomic experts conclude
that, for the average user of average size and average typing
skill, the improved conventional computer keyboard is good
enough. The design is a familiar to most users, and is cost-effective.
Designs to Suit Individual Problems
with using a conventional keyboard can be related to the
posture or the hands, the keying forces, and the repetitive
motion. Consequently, keyboard makers have developed a variety
of alternative ergonomic keyboard designs to solve many
of the problems and to improve work performance for suitable
users. Ergonomic keyboard designs fall into the following
split keyboards. These keyboard designs split
the alphanumeric keys at a fixed angle and slightly tent
the keyboard up (see Microsoft Natural, www.microsoft.com).
Some research evidence indicates reduced discomfort because
of reduced ulnar deviation (i.e., the lateral bending of
the hands). These designs work better for broader, larger-framed
individuals and pregnant women because they put the arms
in a better position to reach around the front of the body.
designs usually address the issue of wrist extension (i.e.,
upwards bending of the hands), however, which is a more
important musculoskeletal injury risk factor than ulnar
deviation. Hunt-and-peck typists will find split keyboards
more difficult to use. The keyboards are generally larger
and wider than conventional keyboards, which in some situations
can put the mouse too far out to the side of the keyboard.
fixed-angle split keyboards. These do not
use conventional keys but have a touch-sensitive surface
that allows the user to key and mouse in the same physical
This design also allows users to control many computer commands
using simple finger gestures, again all performed on the
same physical area. There is a learning curve, but as users
become proficient, the overall speed of computer work performance
can increase by more than 80%.
split keyboards (Goldtouch; www.keyovation.com)
allow users to change the split angle to suit their own
needs. Often their makers link the split angle to the degree
of tenting of the keyboard as well. Some research evidence
indicates reduced discomfort with this kind of design because
of reduced ulnar deviation. These designs do not usually
address wrist extension issues. The user has to decide on
the split angle, which means that they may need some training,
and some users might end up with a split angle that is inappropriate
for them. There
is also a multitouch adjustable-angle split keyboard (Touchstream
Split keyboards are always difficult for hunt-and-peck typists
to use, and these designs are often expensive. Touch typists
should be able to move back and forth easily between straight
keyboards and split keyboards.
makers of completely split keyboards (Kinesis; www.kinesis.com)
split the left-hand and right-hand portions of the keyboard
completely apart. In some designs, keyboard makers present
the keys in a scooped design that allows the hands to rest
in a more neutral posture for typing. Some research evidence
indicates reduced discomfort because of reduced ulnar deviation
and reduced wrist extension. Unfortunately, there is more
of a learning curve, and research shows that initial performance
can suffer a 50% slowing of typing speed. Again,
touch typists have an advantage here. Completely split keyboards
are especially difficult for hunt-and-peck typists to use,
and some of them are very expensive.
split keyboards resemble an accordion. The
user types with the hands facing each other (Safetype; www.safetype.com);
consequently, the typist cannot easily see the keys. This
design works well to reduce ulnar deviation and wrist extension,
but it is important not to have the keyboard too high because
the chest and shoulders can suffer fatigue. This design
is almost impossible for hunt-and-peck typists to use, and
because it is a specialist keyboard, it is expensive.
keyboards (Twiddler; www.handykey.com)
have a smaller number of keys and letters; combinations
of keys in chords generate characters. One-handed and two-handed
designs are available. Research shows that this is like
learning stenography; learning the chords that correspond
to characters requires about 80 hours to get to moderately
fast—a high learning curve. These keyboards are more
expensive than regular keyboards but can be useful to some
users, especially those with special needs, such as a blind
user or one with severely arthritic hands.
keyboards (Datahand, www.datahand.com;
and Orbitouch, www.keybowl.com)
comprise several different designs to assist users with
some physical limitation or who wish to type in a different
way. The Datahand allows users to rest their hands on a
series of switches that detect different directions of finger
movements, and these generate the characters. The Orbitouch
lets users rest their hands on two domed surfaces and then
move these surfaces to generate the characters. Specialist
keyboards often result in slower typing and can have significant
learning curves, so they are not for most users. Like other
alternative keyboard designs, they are expensive, and touch
typists more easily adopt this form than nontouch typists
keyboards (Half-QWERTY; www.aboutonehandtyping.com)
come in several alternative designs. The Half-QWERTY keyboard
uses the same kinds of keys found on a regular keyboard,
but each key functions in two modes to generate all of the
characters of a regular keyboard in a smaller area. One-handed
chordic keyboards (e.g., BAT, www.aboutonehandtyping.com)
and one-handed multitouch keyboards are also available.
Keyboard Design Is Best?
single design is best for everyone. The conventional keyboard
remains the most common design because it can be mass-produced
at low cost and is familiar to most users. However, businesses
may find that other designs increase productivity and offer
less risk of injury. Consequently, keyboard makers have
developed various ergonomic designs to address different
user needs and different work situations.
Chen, PhD, is a professor at Loyola Marymount University,
Los Angeles, Calif.
Alan Hedge, PhD, is a professor at Cornell University,
Dwight Owsen, ABD, is an instructor
of accounting at Long Island University, Brooklyn, N.Y.