Introduction
This article presents an overview of the relationship of Ergonomics (also known as Human Factors) to occupational safety and health (OSH). It describes briefly the historical background of Ergonomics. It describes how ergonomics can be applied to OSH and how it fits with the legislative framework for OSH in the European Union. It summarises the application areas of Ergonomics that relate to OSH and lists professional bodies in ergonomics and current sources of information.
Definition
According to the official definition of the International Ergonomics Association (IEA)[1], ‘Ergonomics (or human factors) is the scientific discipline concerned with the understanding of the interactions among humans and other elements of a system’. The terms ‘Ergonomics’ and ‘Human Factors’ are therefore synonyms and can be used interchangeably, although some do regard them as separate (but complementary) entities. These terms also refer to ‘the profession that applies theoretical principles, data and methods to design in order to optimise human well-being and overall system performance.’ [1].
Practitioners of ergonomics - ergonomists - contribute to the planning, design and evaluation of tasks, jobs, products, organisations, environments and systems in order to make them compatible with the needs, abilities and limitations of people.
Ergonomics is a systems-oriented discipline, which can be applied to all aspects of human activity. In the context of work system, ISO 6385 establishes the fundamental principles of ergonomics as basic guidelines for the design of work systems[2]. In the wider context, ISO 26800 presents the general ergonomics approach and specifies basic ergonomics principles and concepts applicable to the design and evaluation of tasks, jobs, products, tools, equipment, systems, organisations, services, facilities and environments[3]. Ergonomists often work in particular economic sectors or application domains, which are not mutually exclusive and change over time [1].
Historical background
Origins of the term ‘ergonomics’
The word ‘ergonomics ‘ was coined in 1949 by K. F. H Murrell as a combination of two Greek words, εργον (ergon), meaning ‘work ‘, and νομος (nomos) meaning ‘law’[4]. It came to prominence in 1950 when it was used in the name of the ‘Ergonomics Research Society’ (now the Chartered Institute of Ergonomics and Human Factors).
In the 19th century the same term had been coined independently in Poland by Wojciech Jastrzębowski[5] who published Rys ergonomji czyli nauki o pracy, opartej na prawdach poczerpniętych z Nauki Przyrody (The Outline of Ergonomics, i.e. Science of Work, Based on the Truths Taken from the Natural Science) (1857).
Origin of the term ‘human factors’
The terms ‘Human Engineering’, ‘Human Factors’ and ‘Human Factors Engineering’ came into use in the USA during World War 2 in the context of the design of military equipment[6].
Contributing disciplines
Ergonomists makes use of information from a range of scientific disciplines including:
- Anthropometry and biomechanics
- Physiology
- Psychology
- Medicine
- Industrial engineering
- Computer science
Relationship of ergonomics to OSH
Ergonomics is a discipline that can be applied to OSH to help ensure that workplace risks are, prevented at the design stage, eliminated at a later stage, or controlled and reduced if they cannot be eliminated. It can therefore improve the safety, well-being and comfort of workers. It also has broader effects by enhancing the safety of systems of work and therefore, more broadly, of society as a whole. In the specific context of the safety of machinery the need to accommodate ergonomics principles is embodied in ISO 12100[7] and ISO/TR 22100-3[8] provides a more detailed framework for incorporating ergonomics in the design of machines to help ensure their safety.
Legislative frameworks relating to OSH and ergonomics
The most important piece of European legislation relevant to risk assessment is the ‘Framework Directive’[9]. This Directive has been transposed into national legislation. Member States, however, have the right to introduce more stringent provisions to protect their workers[10].
Article 6 of the Framework Directive encourages an ergonomic approach since it requires the employer to adapt the work to the individual, particularly by alleviating monotonous work and work at a predetermined work-rate and by reducing the effect of work on health. Six individual directives[11] [12] [13] [14] [15] [16] were initially made under the Framework Directive, with further individual directives being added making a total (2017) of 24 (including the Framework). The Directives on Manual Handling [14], Display Screen Equipment (DSE) [15]and Personal Protective Equipment (PPE), [13] which were all amongst the first six, are of particular importance to ergonomics. Amongst the first six, the directive on work equipment [12] and the provisions regarding thermal conditions in the directive on the requirements for the workplace [11] also relate to ergonomics issues. None of the further individual directives include any additional requirements relevant to ergonomics.
Specific areas of application of ergonomics to OSH
Physical ergonomics
Physical ergonomics is concerned with human anatomical, anthropometric, physiological and biomechanical characteristics as they relate to physical activity. It covers topics such as working postures,manual handling operations, repetitive movements, work-related musculoskeletal disorders (WRMSDs), workplace layout, safety and health [1].
Environmental ergonomics
In addition to the physical design of the working environment, the environment itself (temperature, lighting, noise, etc.) can have a significant effect on the health, safety and performance of workers. For example, elevated temperatures can impair concentration, increasing human error and the risk of accidents, as well as creating a risk of heat-related illness. A series of ISO Standards provide help and guidance on the design and assessment of physical environments.
Anthropometry
Anthropometry is the science of measurement of the human body. It can be applied to OSH to ensure that workers have sufficient space to perform their tasks, that they can reach necessary equipment, tools and controls, that barriers keep them out of reach of hazards, and that working postures can be optimised for the range of people using them[17].
Ergonomic work design
This refers to the use of ergonomics to design jobs and work systems so that most of the potential workforce can perform well. The ultimate goal is to make it easy for quality work to be done easily without unnecessary risk of injury or illness because of biomechanical, physiological or psychological overload[18]. It will therefore tend to improve the reliability of humans within a system and to reduce the risks of harmful errors occurring.
Musculoskeletal disorders
Musculoskeletal disorders (MSDs) can affect the body's muscles, joints, tendons, ligaments, bones and nerves.
Most work-related MSDs develop over time and are caused either by the work itself or by the employees' working environment. They can also result from accidents, e.g. fractures and dislocations. Typically, MSDs affect the back, neck, shoulders and upper limbs; less often they affect the lower limbs.
Health problems range from discomfort, minor aches and pains, to more serious medical conditions requiring time off work and even medical treatment. In more chronic cases, treatment and recovery are often unsatisfactory - the result could be permanent disability and loss of employment.
Many problems can be prevented or greatly reduced by complying with existing safety and health law and following guidance on good practice. This includes assessing the work tasks, putting in place preventive measures, and checking that these measures stay effective [19].
Physiological fatigue
Exercise induced fatigue has a physiological basis. It is thought to be a warning mechanism that prevents overstrain of the body or a part of the body. It can be general or systematic, or local, usually muscular in nature. It is different from mental or visual fatigue. It is important in the context of OSH because it leads to the reduction in the capacity of muscles to generate force or power output, so may make a fatigued worker less able to perform work tasks, less efficient, and more likely to make errors or suffer injury[20].
Cognitive ergonomics
Cognitive ergonomics is concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system [1]. It therefore relates to OSH through how people process information in hazardous situations.
Human machine interface
A Human Machine Interface (HMI) can be defined[21] as the part of a machine or device which allows the exchange of information between an operator/user and the machine/device. An HMI consists of three parts which are (1) controls / input devices, (2) displays or other output devices, and (3) an inner structure, often consisting of both hardware and computer software.
Deficiencies in an HMI are relevant to OSH as they can cause stress, errors and accidents. Stress can result from cognitive overload or under-load. Operating errors can result in accidents. In high-risk industries, such as nuclear, oil, or gas such errors can result in major accidents.
Human error
The two main types of human failure are errors and violations[22]. A human error is an action or decision which was not intended or has an outcome that was unintended. A violation is a deliberate deviation from a rule or procedure. Both types of failure can have the potential to result in harm to people. Errors can be classified as
- Slips – when something is done that should not have been done;
- Lapses – when something that should be done is omitted;
- Mistakes or errors of judgement or decision-making – which may be due to applying rules badly, or having incorrect or insufficient information.
Violations include non-compliances, circumventions, shortcuts and work-arounds.
Ergonomics in office work
While offices are typically low risk environments, ergonomics relates to OSH in office work in the context of seating and low back pain and the need to encourage movement and avoid prolonged static postures, [23] [24] use of VDU equipment, use of computer software, musculoskeletal disorders, thermal environments, psychological demands, work-related stress and visual fatigue [25] [26]. Recent trends in the development of mobile computing and hand-held computing devices raise ergonomics issues because much “office work” is now taking place outside offices.
Other aspects of ergonomics
Organisational ergonomics
Organisational ergonomics is concerned with the optimisation of sociotechnical systems, including their organisational structures, policies, and processes [1]. It takes into account factors ranging from the design of workstations to the scheduling of rest breaks and job rotation schedules to human resources issues such as promotion opportunities. This approach gives an overview of the OSH risks that each person in the system is exposed to.
Participatory ergonomics
‘Participatory ergonomics’ has been defined as ‘The involvement of people in planning and controlling a significant amount of their own work activities, with sufficient knowledge and power to influence both processes and outcomes in order to achieve desirable goals’[27].
Within ergonomics, the consensus is that the participation of end users in the design of work equipment and workplaces will lead to better design, as these solutions are developed using the expertise and practical experience of the end users. It is also held that a participatory approach will make the solutions more acceptable to the end users and will improve relations between managers and the workers[28].
Gender differences in the workplace
Physical, physiological, psychological, social and cultural differences between men and women mean that ergonomists need to be aware of the influences these differences can have in the workplace. Selection policies and informal self-selection lead to many jobs and tasks within jobs being more associated with either males or females. Real or perceived differences can be associated with different employment patterns for males and females. Jobs, workstations or equipment associated with male employment may be unsuited to female employees, and vice versa. As men and women tend to have different domestic and caring responsibilities outside work, they may prefer different working patterns and hours of work[29].
Work adaptions for individuals with specific needs
The European employment directive aimed at preventing discrimination[30] requires employers to carry out workplace adaptions for people with disabilities. Ergonomics often has a part to play in the process of making modifications to accommodate these individuals, including facilitating keeping them in work or helping them to return to work following injury or ill health. Council Directive 2000/78/EC establishes a general framework for equal treatment in employment and occupation.
