Ergonomic Workstation and Seating Design Factors

What is Ergonomics?

Ergonomics is a scientific discipline concerned with improving the productivity, health, safety and comfort of people, as well as promoting effective interaction between people, technology they are using and the environment in which both must operate.

For industrial workers, ergonomics is especially important due to the cost of outfitting a work area, and also due to the strain and stress of heavier loads and more physical conditions that exist within a warehouse or manufacturing plant.

Ergonomic workstations should be designed to facilitate task performance, minimize fatigue and injury by fitting equipment to the body size, strength and range of motion of the user. Ergonomically designed work benches and seating can reduce pain and injury, increase productivity, improve morale, and decrease complaints.

You should strive to eliminate these things:

1. Static or awkward posture
2. Repetitive motions
3. Poor access or inadequate clearance and excessive reach to products, supplies, tools, or work areas
4. Computer screens or printout displays that are difficult to read and understand
5. Controls that are confusing to operate or require too much force

Therefore, furniture that is selected should be suitable for the types of tasks performed and be adaptable to multi-purpose use. Workstations must be specified carefully to meet the need of the staff and to accomplish the goals of the facility.

What are your people doing at the workstation?

Start thinking about the operational objectives your people are responsible for. There are specific kinds of workbenches designed for nearly every activity, and those are a good place to start. There are three goals to consider in human-centered design: (1) Enhance human abilities, (2) overcome human limitations, and (3) Foster user acceptance. So if you're designing a shipping workstation, start with what your packers will be doing. Reading a terminal; working from a pick list; dealing with cartons and packing materials...the list can be endless. What kind of workstation helps them do it best?

Some workstation design tips from North Carolina State University:

Workstation Height

Correct work station height depends upon the user of a work station and upon the chair and other factors that interact with the user and table.

Leg Room

Leg room (for sitting operations): Knee spaces should allow a worker to feel uncrowded and to allow some changes of position. The knee space should be at least 30" wide by 19"deep by 27" high to comply with the requirements of the Americans with Disabilities Act. For those using a footrest, clearance must be calculated with the legs in place on the footrest. Likewise, depth of the "clearance envelope" for both legs and toes should be evaluated while the workstation user is in a normal working position at the work station (determined by the design of the seating system and the way the user sits). Drawers and support legs (for furniture) should not go where human legs need to fit.

Workbench Top

The work station top should be big enough to allow space not only for all necessary equipment, but also for paperwork, manuals, and other materials needed for the job. Working with materials on chairs and at odd angles has the potential for neck and other body strain. Frequently used items should be kept close to avoid long reaches. A general recommendation is that the work area top should be at least as big as the standard office desk - 30 inches by 60 inches. A depth of at least 30 inches allows flexibility in use/reuse of the work area. Usable space may be maximized by good wire/cable management. Thickness of work surface: one inch.

Seating & Stools

Seat height should be adjustable while seated. Thighs should be horizontal, lower legs vertical, feet flat on the floor or on a footrest.

Backrests, if applicable: The backrest should offer firm support, especially in the lumbar (lower back) region, should be 12-19 inches wide, and should be easily adjustable both in angle and height, while sitting. The optimum angle between seat and back should permit a working posture of at least 90 degrees between the spine and thighs. Seat pan angle and backrest height and angle should be coordinated to allow for the most comfortable weight load on the spinal column.