Human factors and ergonomics

Physical ergonomics: the science of designing user interaction with equipment and workplaces to fit the user.

Physical ergonomics is concerned with human anatomy, and some of the anthropometric, physiological and bio mechanical characteristics as they relate to physical activity.[5] Physical ergonomic principles have been widely used in the design of both consumer and industrial products for optimizing performance and to preventing / treating work-related disorders by reducing the mechanisms behind mechanically induced acute and chronic musculoskeletal injuries / disorders.[12] Risk factors such as localized mechanical pressures, force and posture in a sedentary office environment lead to injuries attributed to an occupational environment.[13] Physical ergonomics is important to those diagnosed with physiological ailments or disorders such as arthritis (both chronic and temporary) or carpal tunnel syndrome. Pressure that is insignificant or imperceptible to those unaffected by these disorders may be very painful, or render a device unusable, for those who are. Many ergonomically designed products are also used or recommended to treat or prevent such disorders, and to treat pressure-related chronic pain.

One of the most prevalent types of work-related injuries is musculoskeletal disorder. Work-related musculoskeletal disorders (WRMDs) result in persistent pain, loss of functional capacity and work disability, but their initial diagnosis is difficult because they are mainly based on complaints of pain and other symptoms.[14] Every year, 1.8 million U.S. workers experience WRMDs and nearly 600,000 of the injuries are serious enough to cause workers to miss work.[15] Certain jobs or work conditions cause a higher rate of worker complaints of undue strain, localized fatigue, discomfort, or pain that does not go away after overnight rest. These types of jobs are often those involving activities such as repetitive and forceful exertions; frequent, heavy, or overhead lifts; awkward work positions; or use of vibrating equipment.[16] The Occupational Safety and Health Administration (OSHA) has found substantial evidence that ergonomics programs can cut workers' compensation costs, increase productivity and decrease employee turnover.[17] Mitigation solutions can include both short term and long-term solutions. Short and long-term solutions involve awareness training, positioning of the body, furniture and equipment and ergonomic exercises. Sit-stand stations and computer accessories that provide soft surfaces for resting the palm as well as split keyboards are recommended. Additionally, resources within the HR department can be allocated to provide assessments to employees to ensure the above criteria are met.[18] Therefore, it is important to gather data to identify jobs or work conditions that are most problematic, using sources such as injury and illness logs, medical records, and job analyses.[16]

Ergonomically designed Keyboard

Innovative workstations that are being tested include sit-stand desks, treadmill desks, pedal devices and cycle ergometers. In multiple studies these new workstations resulted in decreased waist circumference and improved psychological well being. However a significant number of additional studies have seen no marked improvement in health outcomes.[19]

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.[5] (Relevant topics include mental workload, decision-making, skilled performance, human reliability, work stress and training as these may relate to human-system and Human-Computer Interaction design.) Epidemiological studies show a correlation between the time one spends sedentary and their cognitive function such as lowered mood and depression.[19]

Organizational ergonomics is concerned with the optimization of socio-technical systems, including their organizational structures, policies, and processes.[5] (Relevant topics include communication, crew resource management, work design, work systems, design of working times, teamwork, participatory design, community ergonomics, cooperative work, new work programs, virtual organizations, telework, and quality management.)

Some have stated that human ergonomics began with Australopithecus prometheus (also known as “little foot”), a primate who created handheld tools out of different types of stone, clearly distinguishing between tools based on their ability to perform designated tasks.[20] The foundations of the science of ergonomics appear to have been laid within the context of the culture of Ancient Greece. A good deal of evidence indicates that Greek civilization in the 5th century BC used ergonomic principles in the design of their tools, jobs, and workplaces. One outstanding example of this can be found in the description Hippocrates gave of how a surgeon's workplace should be designed and how the tools he uses should be arranged.[21] The archaeological record also shows that the early Egyptian dynasties made tools and household equipment that illustrated ergonomic principles.

Bernardino Ramazzini was one of the first people to systematically study the illness that resulted from work earning himself the nickname “father of occupational medicine”. In the late 1600s and early 1700s Ramazzini visited many worksites where he documented the movements of laborers and spoke to them about their ailments. He then published “De Morbis Artificum Diatriba” (Latin for Diseases of Workers) which detailed occupations, common illnesses, remedies.[22] In the 19th century, Frederick Winslow Taylor pioneered the "scientific management" method, which proposed a way to find the optimum method of carrying out a given task. Taylor found that he could, for example, triple the amount of coal that workers were shoveling by incrementally reducing the size and weight of coal shovels until the fastest shoveling rate was reached.[23] Frank and Lillian Gilbreth expanded Taylor's methods in the early 1900s to develop the "time and motion study". They aimed to improve efficiency by eliminating unnecessary steps and actions. By applying this approach, the Gilbreths reduced the number of motions in bricklaying from 18 to 4.5, allowing bricklayers to increase their productivity from 120 to 350 bricks per hour.[23]

However, this approach was rejected by Russian researchers who focused on the well-being of the worker. At the First Conference on Scientific Organization of Labour (1921) Vladimir Bekhterev and Vladimir Nikolayevich Myasishchev criticised Taylorism. Bekhterev argued that "The ultimate ideal of the labour problem is not in it [Taylorism], but is in such organisation of the labour process that would yield a maximum of efficiency coupled with a minimum of health hazards, absence of fatigue and a guarantee of the sound health and all round personal development of the working people."[24] Myasishchev rejected Frederick Taylor's proposal to turn man into a machine. Dull monotonous work was a temporary necessity until a corresponding machine can be developed. He also went on to suggest a new discipline of "ergology" to study work as an integral part of the re-organisation of work. The concept was taken up by Myasishchev's mentor, Bekhterev, in his final report on the conference, merely changing the name to "ergonology"[24]

Prior to World War I, the focus of aviation psychology was on the aviator himself, but the war shifted the focus onto the aircraft, in particular, the design of controls and displays, and the effects of altitude and environmental factors on the pilot. The war saw the emergence of aeromedical research and the need for testing and measurement methods. Studies on driver behavior started gaining momentum during this period, as Henry Ford started providing millions of Americans with automobiles. Another major development during this period was the performance of aeromedical research. By the end of World War I, two aeronautical labs were established, one at Brooks Air Force Base, Texas and the other at Wright-Patterson Air Force Base outside of Dayton, Ohio. Many tests were conducted to determine which characteristic differentiated the successful pilots from the unsuccessful ones. During the early 1930s, Edwin Link developed the first flight simulator. The trend continued and more sophisticated simulators and test equipment were developed. Another significant development was in the civilian sector, where the effects of illumination on worker productivity were examined. This led to the identification of the Hawthorne Effect, which suggested that motivational factors could significantly influence human performance.[23]

World War II marked the development of new and complex machines and weaponry, and these made new demands on operators' cognition. It was no longer possible to adopt the Tayloristic principle of matching individuals to preexisting jobs. Now the design of equipment had to take into account human limitations and take advantage of human capabilities. The decision-making, attention, situational awareness and hand-eye coordination of the machine's operator became key in the success or failure of a task. There was substantial research conducted to determine the human capabilities and limitations that had to be accomplished. A lot of this research took off where the aeromedical research between the wars had left off. An example of this is the study done by Fitts and Jones (1947), who studied the most effective configuration of control knobs to be used in aircraft cockpits.

Much of this research transcended into other equipment with the aim of making the controls and displays easier for the operators to use. The entry of the terms "human factors" and "ergonomics" into the modern lexicon date from this period. It was observed that fully functional aircraft flown by the best-trained pilots, still crashed. In 1943 Alphonse Chapanis, a lieutenant in the U.S. Army, showed that this so-called "pilot error" could be greatly reduced when more logical and differentiable controls replaced confusing designs in airplane cockpits. After the war, the Army Air Force published 19 volumes summarizing what had been established from research during the war.[23]

In the decades since World War II, human factors has continued to flourish and diversify. Work by Elias Porter and others within the RAND Corporation after WWII extended the conception of human factors. "As the thinking progressed, a new concept developed—that it was possible to view an organization such as an air-defense, man-machine system as a single organism and that it was possible to study the behavior of such an organism. It was the climate for a breakthrough."[25] In the initial 20 years after the World War II, most activities were done by the "founding fathers": Alphonse Chapanis, Paul Fitts, and Small.

The beginning of the Cold War led to a major expansion of Defense supported research laboratories. Also, many labs established during WWII started expanding. Most of the research following the war was military-sponsored. Large sums of money were granted to universities to conduct research. The scope of the research also broadened from small equipments to entire workstations and systems. Concurrently, a lot of opportunities started opening up in the civilian industry. The focus shifted from research to participation through advice to engineers in the design of equipment. After 1965, the period saw a maturation of the discipline. The field has expanded with the development of the computer and computer applications.[23]

The Space Age created new human factors issues such as weightlessness and extreme g-forces. Tolerance of the harsh environment of space and its effects on the mind and body were widely studied.[26]

The dawn of the Information Age has resulted in the related field of human–computer interaction (HCI). Likewise, the growing demand for and competition among consumer goods and electronics has resulted in more companies and industries including human factors in their product design. Using advanced technologies in human kinetics, body-mapping, movement patterns and heat zones, companies are able to manufacture purpose-specific garments, including full body suits, jerseys, shorts, shoes, and even underwear.

The Institute of Occupational Medicine (IOM) was founded by the coal industry in 1969. From the outset the IOM employed an ergonomics staff to apply ergonomics principles to the design of mining machinery and environments. To this day, the IOM continues ergonomics activities, especially in the fields of musculoskeletal disorders; heat stress and the ergonomics of personal protective equipment (PPE). Like many in occupational ergonomics, the demands and requirements of an ageing UK workforce are a growing concern and interest to IOM ergonomists.

The International Society of Automotive Engineers (SAE) is a professional organization for mobility engineering professionals in the aerospace, automotive, and commercial vehicle industries. The Society is a standards development organization for the engineering of powered vehicles of all kinds, including cars, trucks, boats, aircraft, and others. The Society of Automotive Engineers has established a number of standards used in the automotive industry and elsewhere. It encourages the design of vehicles in accordance with established human factors principles. It is one of the most influential organizations with respect to ergonomics work in automotive design. This society regularly holds conferences which address topics spanning all aspects of human factors and ergonomics.

Contemporary offices did not exist until the 1830s,[30] with Wojciech Jastrzębowsk's seminal book on MSDergonomics following in 1857 [31] and the first published study of posture appearing in 1955.[32]

As the American workforce began to shift towards sedentary employment, the prevalence of [WMSD/cognitive issues/ etc..] began to rise. In 1900, 41% of the US workforce was employed in agriculture but by 2000 that had dropped to 1.9% [33] This coincides with an increase in growth in desk-based employment (25% of all employment in 2000) [34] and the surveillance of non-fatal workplace injuries by OSHA and Bureau of Labor Statistics in 1971.[35] 0–1.5 and occurs in a sitting or reclining position. Adults older than 50 years report spending more time sedentary and for adults older than 65 years this is often 80% of their awake time. Multiple studies show a dose-response relationship between sedentary time and all-cause mortality with an increase of 3% mortality per additional sedentary hour each day.[36] High quantities of sedentary time without breaks is correlated to higher risk of chronic disease, obesity, cardiovascular disease, type 2 diabetes and cancer.[19]

Currently, there is a large proportion of the overall workforce who is employed in low physical activity occupations.[37] Sedentary behavior, such as spending long periods of time in seated positions poses a serious threat for injuries and additional health risks.[38] Unfortunately, even though some workplaces make an effort to provide a well designed environment for sedentary employees, any employee who is performing large amounts of sitting will likely suffer discomfort.[38] There are existing conditions that would predispose both individuals and populations to an increase in prevalence of living sedentary lifestyles, including: socioeconomic determinants, education levels, occupation, living environment, age (as mentioned above) and more.[39] A study published by the Iranian Journal of Public Health examined socioeconomic factors and sedentary lifestyle effects for individuals in a working community. The study concluded that individuals who reported living in low income environments were more inclined to living sedentary behavior compared to those who reported being of high socioeconomic status.[39] Individuals who achieve less education are also considered to be a high risk group to partake in sedentary lifestyles, however, each community is different and has different resources available that may vary this risk.[39] Oftentimes, larger worksites are associated with increased occupational sitting. Those who work in environments that are classified as business and office jobs are typically more exposed to sitting and sedentary behavior while in the workplace. Additionally, occupations that are full-time, have schedule flexibility, are also included in that demographic, and are more likely to sit often throughout their workday.[40]

Obstacles surrounding better ergonomic features to sedentary employees include cost, time, effort and for both companies and employees. The evidence above helps establish the importance of ergonomics in a sedentary workplace, yet missing information from this problem is enforcement and policy implementation. As a modernized workplace becomes more and more technology based more jobs are becoming primarily seated, therefore leading to a need to prevent chronic injuries and pain. This is becoming easier with the amount of research around ergonomic tools saving money companies by limiting the number of days missed from work and workers comp cases.[41] The way to ensure that corporations prioritize these health outcomes for their employees is through policy and implementation.[41]

Nationwide there are no policies that are currently in place, however a handful of big companies and states have taken on cultural policies to insure the safety of all workers. For example, the state of Nevada risk management department has established a set of ground rules for both agencies responsibilities and employees responsibilities.[42] The agency responsibilities include evaluating workstations, using risk management resources when necessary and keeping OSHA records.[42] To see specific workstation ergonomic policies and responsibilities click here.[42]

Problems related to measures of usability include the fact that measures of learning and retention of how to use an interface are rarely employed and some studies treat measures of how users interact with interfaces as synonymous with quality-in-use, despite an unclear relation.[53]

Although field methods can be extremely useful because they are conducted in the users' natural environment, they have some major limitations to consider. The limitations include:

1. Usually take more time and resources than other methods
2. Very high effort in planning, recruiting, and executing compared with other methods
3. Much longer study periods and therefore requires much goodwill among the participants
4. Studies are longitudinal in nature, therefore, attrition can become a problem.[54]