The computerized workplace should not only satisfy minimum ergonomic requirements, but also incorporate new technologies and research findings in work physiology and ergonomics.

Production process mechanization and automation has been accompanied by a shift of employees from the area of product manufacture to that of services—or offices, largely to computerized workplaces. This means, among others, more people who work in the sitting position. Work performed at the desk is theoretically less taxing and a lighter strain on the body. Theoretically—because despite the immense progress in office furniture and equipment design in recent decades, the focal point at the office remains the employee—seated on a simple chair with poor posture, head inclined towards the monitor. While the requirements on these kinds of employees are growing, man’s ability to adapt to unfavorable work conditions does not mean that they have no negative effect on health. The effect is deteriorating work productivity—both work efficiency and quality.

How can this phenomenon be prevented? First, through the creation of a proper, ergonomic workstation. Of help in this area in Poland may be the Ordinance of the Minister of Labor and Social Policy of Dec. 1, 1998, in effect since March 1999, on work safety and hygiene at workstations equipped with monitors (Dziennik Ustaw journal of laws of Dec. 10, 1998, Dz. U. 98.148.973). An integral part of the order is an appendix defining the minimum requirements of work safety and hygiene and ergonomic conditions to be met by workstations equipped with monitors. The appendix, as its title suggests, only includes recommendations for a safe workplace, one that does not pose any health hazards or cause employee health to decline. The appendix should not be regarded, however, as a formula for a modern ergonomic computer workstation, although elimination of harmful factors is relatively simple according to the relevant conditions listed in the appendix. These include electromagnetic field and radiation, lighting, noise and poor posture.

Despite the implementation of these and similar standards contained in the document, some employees may still suffer from ailments connected with desk work, particularly those who work long hours on data entry. Moreover, work with a computer requires personnel to interact with changing elements on the screen and edit graphic materials in a coordination of intensive visual exertion with precise mouse movements. Some difficulties in this respect may also result from poor adjustment of the workstation to the needs and preferences of the employee, who may not be aware of the need to make certain changes in his work environment or is unable to do so. Even if work conditions do not have a negative influence on health, they can still aggravate stress and exhaustion. The outcome is reduced productivity, measured mainly in terms of efficiency, for example the number of operations performed in a given time. Tired employees are also less alert, which results in more mistakes on the job—and potential losses for the employer.

The workstation
Higher productivity means first and foremost optimum use of staff potential and skills. High quality computer equipment and the best possible work conditions can make this possible.

Computer work conditions boil down to minimizing the consequences of extended periods in a sitting position. The following graph presents the possible health effects of this kind of job.

Optimization of the computer workstation should involve the following components:
● furniture (chairs, work tables, auxiliary furniture)
● spatial configuration of workstation equipment (position of the monitor, keyboard, mouse, printer, etc.)
● workstation lighting (intensity of general lighting, eliminating glare)
● work organization (optimal work breaks, combining tasks causing mental stress with light physical work)

The basic element of an ergonomic computer workstation should be a work table, not a typical desk, whose dimensions ensure:
a) sufficient space for operating the elements of workstation equipment and perform actions connected with the task in question
b) a keyboard position that is no fewer than 100 mm from the front edge of the desktop
c) the position of equipment elements at an adequate distance from the worker, or within easy reach.

The latest drawers are designed with a negative inclination angle since intensive use of the keyboard and the mouse placed directly on the table top requires the hands to remain in a tilted position. The situation worsens if the back of the keyboard is elevated. The wrist pads promoted one year ago as an accessory for keyboard use, rather than reducing wrist discomfort, actually aggravate it even further by placing additional pressure on the carpal tunnel. According to the current trends in ergonomics, only keyboard placement with a negative inclination angle prevents wrist problems. Special elbow pads and forearm supports mounted on the table top may also be helpful.

Comfort also requires a table that ensures a natural arm position during use of the keyboard, proper monitor observation angle—the upper edge of the monitor should not be above the eyes of the user, and adequate space for the legs.

The ergonomic table should also adjust easily to each individual’s needs, including an adjustable work surface of at least 64-84 cm. Extending this range to about 64-113 cm will enable almost any worker to function in both a sitting and standing position. Tables equipped with two independently adjusted height regulation systems ensure that both the monitor and keyboard are in the correct position.

The chair
Another critical element of the workstation is the chair. According to the report, it should be stable with at least five legs on casters; a backrest and seat that ensures both comfort and freedom of movement; proper regulation of the seat and backrest height, backrest inclination and properly profiled seat, backrest and elbow pads.

As a rule, employers tend to equip their workers with the simplest chairs on the market, while more expensive models are granted to upper management. However, an “economic chair,” which allows personnel to work effectively and comfortably actually comes with a price tag of zl.600-1,000. These models incorporate mechanisms and technologies that until a few years ago were only available in luxury arm chairs. Here are some examples of reasonably priced ergonomic chairs: T-bar and Master office chairs from the Quo Sideo-Nowy Styl system, Uwu and Fast (PROFIm), EL-100 and Reality (Sitag Polska), the system 5000 (Kinnarps Polska) and Onda (Martela Design Center). These models differ first and foremost in terms of design and individual regulation functions. What do they have in common? A design that makes sitting comfort the ultimate priority and adaptability to the needs and preferences of even the most demanding user. All feature adequate seat and backrest profiles for proper positioning of the pelvis and support for the lumbar section of the spine. All come with synchromechanisms enabling freedom of movement, while preserving constant support for the back. Although very different, synchromechanism technical solutions all share one concept: the best possible adjustment of the simultaneous movement of the seat and the backrest to the needs and preferences of today’s office employee.

All these chairs can be equipped with adjustable elbow pads and feature a choice of finishing elements, from chrome stands and a variety of materials used for the backrest such as traditional plywood panels upholstered with foam, plastic plates and metal frames covered with netting to upholstery materials of various texture and color and plastic elements.

Chair comfort is a subjective concept, so the choice of a chair to meet the needs and expectations of the user requires a personal approach. An optimal solution would allow personnel to test a given model before purchase. In order to make full use of chair adjustment, users should become familiar with related functions and instructions for their operation.

Another indispensable complement of ergonomic furniture is proper training for employees that addresses:
• the physiology of the sitting position
• negative effects of an improper sitting position on health
• options for adjusting the workstation to user possibilities and preferences
• proper performance of professional operations at the computer workstation—changing body position, taking breaks.

Only a combination of ergonomic furniture and staff awareness of the importance of their work environment will lead to greater productivity.

Prevention of the most popular ailments affecting those who sit many hours in front of the computer is a considerable challenge. For example:
● pain in the lumbar, chest and neck regions and numbness in the lower limbs can be prevented by a chair that is adapted to the user’s anthropometric conditions: a proper chair height in relation to the table top, movement and mandatory breaks for simple exercises;
● pain in the upper limbs, wrist problems can be avoided by adequate keyboard and mouse positioning;
● pain in the lumbar and neck regions as well as eye problems—through proper position of the monitor.

Effects of maintaining proper body posture; based on Work Improvements in Small Businesses through Ergonomic Intervention by Isao Koide Toyota Motor Corporation

Zbigniew W. Józwiak, Ph.D.
Department of Work Physiology and Ergonomics