Ergonomics in action: a practical guide for the workplace 

Ergonomics front cover
  • by Céline McKeown
  • Price £30
  • Softback, 256 pages
  • ISBN 978 0 901357 47 2

Ergonomics is the discipline that focuses on people and their environment. Within that environment, ergonomics looks at the work that people perform, the equipment and tools they use, the conditions in which they work and the psychosocial aspects of their workplace. The aim of ergonomics is to improve the ‘fit’ between people and the environment in which they work.

Ergonomics in action: a practical guide for the workplace is a no-nonsense introduction to the principles of workplace ergonomics, focusing on the design process, job design and work organisation. It covers specific areas of ergonomic importance, including hand tools, computer use and manual handling, and also addresses the complex and sometimes controversial topic of upper limb disorders.

Praise for the second edition, published as Workplace ergonomics: a practical guide:

“A first class publication ... of real value to those who are faced with ergonomic workplace problems ... useful to those studying for health and safety examinations ... will help the reader gain a fundamental understanding of core subject issues in an easy to read format that is both enjoyable and a very worthwhile read”

Ergonomics Abstracts

“A wealth of guidance and helpful summary points ... contains knowledge which is essential for areas of work that are crying out for ergonomics to be applied now ... pitched at the right level for non-ergonomists ... collates a number of key sources ... helpful as a support to basic training courses”

The Ergonomist

Example

Design features

Hand or arm injuries following the use of tools may indicate inappropriate tool design or improper use. Such injuries can range from something as simple as a callus or blister, to something more severe such as a ULD. In most instances, injuries can be avoided by ensuring that tools are properly designed, taking both the user and the task into account.

Handle design

One of the most common complaints made by workers is that they have to bend their wrist when using tools. For some reason, designers have until recently designed most tools with straight handles and heads. As a result, when the tool user works on or against a flat surface, they will usually have to bend their wrist.

The user experiences a loss of grip strength from working with a bent wrist. To overcome this problem, and to control the tool fully, the pressure of the grip may be increased. Increasing the grip pressure will speed up the rate at which the muscles fatigue. Therefore, to avoid the reduction of grip strength and subsequent acceleration of muscle fatigue, maintaining a straight wrist should be a primary design and selection consideration. This can be achieved easily in many work situations by bending the handle (see below).

In some situations, bending of the wrist can be eliminated by providing a pistol grip tool where the handle is bent by 70–90º. However, this design is only acceptable if used in an appropriate orientation. In general, pistol grip tools should only be used when the tool axis is horizontal. If the tool axis is vertical or the force is applied perpendicularly to the work plane, a straight grip should be used. Examples of wrist posture, tool design and orientation of use are shown below.

Handle construction

If users have to work with a tool which has a smooth, hard handle constructed of a material such as flat metal or plastic, they may experience difficulty in stopping their hand from sliding across the handle as they apply force. To prevent the hand from moving, the user will increase the pressure of the grip – this situation is made worse if their hands are hot and sweaty.

Care should be taken if the handle is designed with flutes or ridges (eg a screwdriver). If these flutes or ridges are too deep or have sharp edges, they may increase the pressure placed on the soft tissue of the hand when the user grips the handle and this may result in discomfort and pain. Soft oval indents on a handle are preferable – they allow improved purchase without causing pressure points.

If handles are made of metal, they may remain cold throughout the course of the shift. Exposure to colder temperatures may increase the possibility of a user developing a ULD, so the use of metals in handle design should be avoided.

It is recommended that soft, compliant and textured materials are used on handles so that they are easier to grip, although care needs to be taken that these cannot be damaged easily, subsequently presenting sharp edges.