U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health

Alternative Keyboards

Purpose

1

To date, there is little information to assist

people interested in purchasing alternative

keyboards. While the scientific evidence

about whether alternative keyboards prevent

musculoskeletal disorders is inconclusive at

this time, this document provides basic

information about common alternative

keyboard designs and their effects on work

posture.
Why Redesign the Keyboard?

When typing, holding the hands and wrists in a

neutral work posture--where the hands are

extended straight without significant bending at

the wrist-- is thought to reduce the risk of

musculoskeletal problems. Computer users

sometimes use awkward or non-neutral work

postures when working on the traditional

keyboard. They rotate their forearms so that

A

B

2
their palms are facing the keyboard (A), and

they often bend their hands outward (B) and

upward (C & D). Sometimes, workers also hold

their elbows slightly away from their bodies (E)

while keying, particularly when the keyboard

surface is too high. Alternative keyboards can

help keep wrists straight as shown on the

following pages.

C

D

E

3
Alternative keyboards use different designs

to attempt to change the user’s posture. The

following are some of the more common

designs.

Split keyboards

Split keyboards are designed to straighten the

wrist. This can be done in two ways: by

increasing the distance between the right and

left sides of the keyboard or by rotating each

half of the keyboard so that each half is

aligned with the forearm. Some alternative

keyboards combine these two methods.

Split and Rotated Keyboard with Wrist Rest

What’s Different About

Alternative Keyboards?

4
Tented keyboards

On tented keyboards, the two keyboard halves

are tilted up like a tent. This feature is a variation of the split keyboard and reduces the

rotation of the forearms.

Built-in wrist or palm rests

Built-in wrist or palm rests help prevent bending the hands up by providing support that

straightens the wrists. It should be noted that

questions do remain about the usefulness of

wrist or palm rests. For example, it is unclear

whether they increase pressure on the wrists,

relieve loads on shoulder and upper back

muscles, or interfere with typing.

Split and Tented Keyboard

5
Key position

Some alternative keyboard designs have

attempted to “fit” the different lengths of the

fingers by curving the rows of keys or by

placing the keys in concave wells. This is

believed to allow the fingers to work in a more

relaxed posture (see illustrations on next page).

What’s Different About

Alternative Keyboards? (Continued)

Keyboard with

Negative Slope

6

Adjustable negative slope

Keyboards with a negative slope also help

prevent bending the hand too far up by allowing

the user to raise the front edge of the keyboard,

or to slope the keyboard backward, thus

straightening the wrist.

Conventional

Keyboard
Concave Well Keyboard

Curved Keyboard

Straight Keyboard

7
Alternative keyboards have been shown to

promote neutral wrist posture. Yet, available

research does not provide conclusive

evidence that alternative keyboards reduce

the risk of discomfort or injury.

Thus, further research is needed before

specific keyboard features can be

recommended with great confidence.

Do Alternative Keyboards

Prevent Injuries?

8
What if I Want to Use an

Alternative Keyboard?

If alternative keyboards are to be used in

the workplace, the following suggestions

may be helpful in making purchasing

decisions.

Determine whether the keyboard is

compatible with existing hardware and

software and whether the keyboard can

accommodate other input devices, such

as trackballs and mice.

Assess how the keyboard will fit with

the workstation. Some alternative

keyboards are extra wide, long, or high

and may not fit on standard keyboard

trays. Such keyboards may also prevent

the tray from retracting under the work

surface. Additionally, some alternative

keyboards, particularly tented versions,

must be placed on surfaces that are

lower than those required for the

conventional keyboard to achieve

proper working posture.

Evaluate whether the keyboard will

affect the performance of the user.

Some alternative keyboard designs and

adjustments make it difficult to see the

9
keys. This is particularly important for

users who rely on key visibility, such as

“hunt and peck” typists. Also, check

whether the job requires use of the

numeric keypad and specialized keys,

because some alternative keyboards

eliminate or reconfigure these keys.

Allow users to try a keyboard on a trial

basis before buying it. It would seem

reasonable to try the keyboard for at

least one to two weeks, since studies

show that this amount of time is

necessary to adapt to alternative

keyboards.

Alternative keyboards are like other

office equipment, furniture or

accessories. Preferences will vary and

one type will not “fit” everyone or every

type of task. Allow users to try a

number of different alternative

keyboards before making decisions

about which ones to buy. If a user wants

to retain his or her conventional

keyboard, respect that decision.

What if I Want to Use an

Alternative Keyboard? (Continued)

10
Expect frustration until users become

familiar with the new keyboards.

Frustration frequently results from

diminished productivity as workers get

used to new equipment.

Involve a specialist in the

decision-making process. This

specialist should have both knowledge

and experience in office ergonomics. If

a computer user has discomfort or

musculoskeletal symptoms, a health

professional should also be involved in

making the decision to purchase an

alternative keyboard.

Integrate a new alternative keyboard

into the work process carefully. Make

sure that users are trained in the

appropriate use of the product, since

many alternative keyboards can be

used incorrectly. If the keyboard is

adjustable, encourage users to change

the adjustments gradually from the

conventional (flat) configuration.

11
A keyboard is only one part of a computer

workstation setup that may influence comfort.

Other important factors include: workstation

and chair adjustability; placement of

equipment, accessories, and work materials;

lighting; and the design and organization of

work tasks.

Because computer work is highly repetitive and

promotes static postures, it can cause

discomfort over long periods of time. It is

important to break up long sessions of keyboard

work with frequent rest breaks or with other

tasks that require movements different from

those used to type or operate the mouse.

12

What Can Be Done to Prevent

Musculoskeletal Injuries?
Keep in mind that it is essential to examine the

entire work environment to determine all

possible causes of discomfort. In other words, it

is unlikely that changing only one workplace

element, such as a keyboard, will eliminate all

discomfort and disorders.

In addition, each workplace should have a

comprehensive ergonomics program in place to

protect all workers.

13

Call NIOSH at

1-800-35-NIOSH

(1-800-356-4674)

or visit the NIOSH Homepage at

http://www.cdc.gov/niosh/homepage.html

to receive:

• A bibliography on alternative keyboard research.

• Information on implementing an ergonomics

program (request Elements of Ergonomics

Programs: A Primer Based on Workplace

Evaluations of Musculoskeletal Disorders

DHHS (NIOSH) Publication No. 97-117).

• More information on workplace safety and

health issues.
For additional information,

contact NIOSH at:

1-800-35-NIOSH

(1-800-356-4674)

Fax number: (513) 533-8573

or

visit the NIOSH Home Page on the world Wide Web at

http://www.cdc.gov/niosh/homepage.html

DHHS (NIOSH) Publication No. 97-148

The National Institute for Occupational Safety

and Health (NIOSH) is the Federal agency

responsible for conducting research and

making recommendations for the prevention

of work-related disease and injury. The

Institute is part of the Centers for Disease

Control and Prevention.