Office Ergonomics - Wrist Rests

A "wrist rest" is a device designed to support the users wrists when using a keyboard(Figure 1) or a computer mouse  (Figure 2).

Figure 1

Figure 2

The primary difference between a wrist rest and a palm support depends on how the hands are placed on the device. When used correctly, a wrist rest provides direct support to the wrists, while palm support gives support to the base of the palms, without placing pressure upon the wrists.

When using a palm support, CSA Z412:24-Office Ergonomics standard suggests that the usefulness of the palm support will depend upon:

a) the design of the workstation and computer equipment such as the keyboard,

b) the typing skills of the user,

c) the type of task performed, and  

d) the posture the user prefers.  

Debate surrounds the use of wrist rests for workers who use a keyboard and perform other repetitive tasks with their hands from a sitting position for extended periods.

On one side of the debate, it is known that leaning the wrists on a wrist rest or the edge of the desk for long periods can put a lot of pressure on the carpal tunnel area in the wrist and restrict blood flow to and from the hand. This pressure may contribute to the development of carpal tunnel syndrome (CTS). On the other hand, evidence shows that wrist rests alleviate tension in the neck and shoulders.

Both views can be challenged.

Contact between the wrists and the wrist rest, if too frequent or too heavy, can indeed cause problems due to excessive pressure on the delicate tendons on the underside of the wrist, and has been known to result in CTS and tenosynovitis (inflammation of the sheath surrounding tendons). This resulting condition may be what has led people to believe that wrist rests should not be used. However, in other cases, individuals without a wrist rest would place their wrists on the sharp edges of the desk. In these cases, a softer wrist rest may  help lessen the pressure.

A worker with a properly adjusted chair and desk might need only very light wrist support, if any. It is important to make sure that your wrists do not rest on the desk or are placed too heavily on a wrist rest. However, even minimal support for the forearms or wrists with arm rests and wrist rests can significantly  of muscular tension out of the neck, shoulders and arms, without subjecting other parts of the body to unnecessary pressure or strain.

The aim is to keep your wrists in a neutral position (not bent up or down). If used, any rest device should be selected as part of an ergonomically-designed workstation. When choosing a rest, the Occupational Safety and Health Agency  (OSHA) (U.S.A.) suggests that:

• Your hands should move freely and be elevated above the wrist/palm rest while typing. When resting, the pad should contact the heel or palm of your hand, not your wrist.
• If used, wrist/palm rests should be part of an ergonomically-coordinated computer workstation.
• Reduce bending of the wrists by adjusting other workstation components (chair, desk, keyboard) so the wrist can maintain an in-line, neutral posture.
• Match the wrist support to the width, height, and slope of the front edge of the keyboard (keeping in mind that the goal is to keep wrist postures as straight as possible).
• Provide wrist/palm supports that are relatively  soft and rounded to minimize pressure on the wrist. The support should be at least 3.8 cm (1.5 inches) deep.

For tasks that involve working with shoulders raised, elbows held out, arms held forward and wrists held up (as in typing, micro-electronics assembly, etc.), any means of reducing muscular tension is important in preventing musculoskeletal disorders 

One's personal preference for using or not using a wrist rest is a very significant factor. Workers who choose not to use them during  a rest break or between tasks. An adjustable workstation which is aligned to the individual using it is essential.