Ergonomics is making headway in the United States as American organizations realize that they are paying a price for not eliminating human wear and tear at computer terminals.
The problems of employee alienation and human error that are the products of strain and discomfort at terminals can be cured and prevented by applying ergonomics-the systematic method of arranging the work environment so that employees can achieve maximum efficiency.
Why is U.S. management just beginning to address the human factor at the terminal? The answer lies in the rapid incursion of computer terminals into American organizations.
At first, terminals in offices were uncommon; using them was a challenging experience; and the first people chosen to operate them were also uncommon. Strains and discomforts were accepted as necessary accompaniment to the exciting new technology. But, as terminals and operators multiplied, so did human problems.
Time intensifies the wear and tear. Conditions which new operators might accept as nuisances sooner or later become intolerable. The causes lie in equipment design that allows screens to assault the eyes with glare, reflections, flickering and just plain poor readability.
When computers were new to organizations, they tended to be set apart and the environment was adapted to their use. Now, as terminals proliferate throughout normal work areas, builtin handicaps follow. The lighting that was ideal for a group of 20 clerical employees using typewriters or other manual equipment can be all wrong for the operators of terminals in the same location.
Much of the human wear and tear is the result of poorly designed/selected tables and chairs. The selection of furniture for terminals is of ten a fleeting afterthought that follows extensive deliberations over the choice of terminals. It's something of a holdover from the practice of putting all office typewriters on the same kind of table, and giving the operator a chair which has only one ergonomic feature--a manual seat-height adjustment. Terminals, however, aren't typewriters and an adjustment in seat height does not offer an operator the supportive working environment required for efficient operation.
The toll of such factors can no longer be ignored. The National Institute for Occupational Safety and Health (NIOSH) has found that employees who primarily operate terminals have more health complaints than non-user employees.
When operators must make do with terminals, environments, and furniture that are ergonomically inadequate, the results include:
- Blurred vision, itching and burning eyes, and headaches that may be due to flickering screens, glare and poor contrast control. An unsatisfactory screen-to-eye distance or a poor screen angle also contribute to the problem.
- Fatigue and neck and back aches that are common among operators straining to overcome visual discomfort by trying to deal with awkward unchangeable positioning of the keyboard or screen.
- Other ailments that may be less common, but more severe. They include pack pains suffered in shifting a terminal and stand so that the screen does not face a window view of the late afternoon sun or reflect the sane, or in adjusting to a poorly designed chair.
Elimination of the causes of such disorders can be accomplished by applying ergonomic design which creates equipment and office environments that fit human needs by applying a combination of physiology, psychology, anthropometry and other studies. Anthropometry relates measurements of the body and its movements to the design of equipment and furniture-- utilizing up to 182 body dimensions.
Many of the advances in office ergo-nomics originated in Sweden, where unions and government have supported standards for well-designed computer equipment and furniture. One of the most widely ac-cepted standards was the introduction of the five-strut base for pedestal swivel chairs.
An optimal table arrangement is one which provides separate surfaces for screen and keyboard units. A split-sur-face design offers a full range of adjust-ments which allow the operator to position the keyboard and screen perfectly for his or her needs.
At such tables, operators can adjust surface heights pneumatically, swivel each surface, tilt the rear surface to the most convenient screen angle, and change the distance between keyboard and screen. Ease of adjustment is especially important when more than one operator uses a terminal.
Terminal screens should be free of glare and reflection, and large enough to be read easily. Images should be well-defined and stand out against a back-ground of good contrast. The terminal body and keys should be finished to con-trol glare. Keyboards should be designed for comfortable and uncomplicated use, with attention to the natural angle and support of both the operators s wrist and hand while keying.
Efficient and strainfree operation is still not likely unless a careful choice is made of both the table-one that is right for the equipment, the site and the nature of the terminals use-and chair. In each case, the crit-ical question is one of the degree to which the operator can adjust the furni-ture to suit his or her size, vision, and other physical characteristics.
Major points to look for when choosing a chair are five struts on the base for balance, a mechanism for height adjustment which can be operated from a sitting position, an adjustable back rest for support of the lower lumbar area, and firm contour padding to pre-vent excessive body shifting. If the chair has arms, check that they are re-cessed to permit unobstructed access to the keyboard while maintaining proper back support.
A table with a single surface top can still provide ergonomic benefits provided that its surface height can be adjusted.
For concentrated work at a station-ary location, a table desk with recessed well allows comfortable arm and hand positions for the operator, as well as height and angle adjustment of the surface.
A table with a single surface or a recessed well can take on more ergonomic features if the screen unit is mounted on a sliding tray. The tray allows the oper-ator to move the screen forward or back, and to adjust the vertical angle.
For a work station with limited space, or situations in which the opera-tor works in a standing position, a wall- mounted terminal can be a practical solu-tion. Separate surfaces for screen and keyboard are mounted on slotted wall rails at the desired heights. The key-board surface glides out from the wall on ball bearings and back out of the way when not in use.
The University of Petroleum and Min-erals in Dhahran, Saudi Arabia, has paid particular attention to ergonomics in arranging furniture and equipment to sup-port its automated cataloging system. Modular furniture is configured so that each terminal is shared by two people: either two catalogers or a cataloger and a typist. This allows cataloging staff to switch back and forth between online and of f line tasks, improving utilization of expensive equipment, and reducing the likelihood of long, unbroken stints fac-ing the terminal.
A feeling of privacy is aided by arranging desks so that people are seated facing away from each other.
Terminals are set up with the key-boards approximately 70 cm above floor level; work surface and chair heights may be adjusted further if desired. Copy holders keep flat work in the same sight plane as the terminal screen.
As more libraries turn to automa-tion to contain costs and increase effi-ciency, it will behoove administrators and planners to address this aspect of system implementation.
