Work station design and layout play the most critical role in eliminating postural problems and other sources of injury. Musculoskeletal injury and visual fatigue are the primary concerns associated with computer workstations. Fortunately these can be reduced through proper workstation design and use.

A first step in ergonomic evaluations is to establish the optimum posture of the operator. This ensures heights and angles of equipment (e.g. chair, table, copy holder, keyboard, monitor etc.) fit the individual, which in turn helps increase comfort and productivity.

The chair should be easily adjustable to provide good support to your lower back and allow up/down movements for proper height interface with the keyboard. The seat should have the ability to tilt forward or backward and the chair should be fitted with casters if tasks require the operator to get up or move around the workstation frequently.

Body posture should be as shown with right angles at the elbow, hip and knee. The head should be held in a neutral position facing straight ahead with the eyes gazing forward or slightly down.

A foot rest may be needed when the operator's feet do not comfortably reach the floor, although this should not be necessary if both the table and the chair are height-adjustable. The feet should reach and touch the floor in a flat, relaxed manner. Foot and leg circulation will be affected if over extension of the feet occurs, as is the case when user wears high-heeled shoes.

The keyboard support table can be adjusted to allow proper upper body posture, or the chair height can be adjusted to achieve the same purpose. The keyboard should be detachable to permit flexible positioning between 5 to 25 degrees. A wrist rest should be available for those who desire it. Keeping the wrist level straight and in a relaxed position offers the worker maximum comfort for extended hours of work.

A document holder should be provided and adjustable in height and angle of tilt, to the same height and plane that the operator views the majority of the time. Usually the position will be at or just below screen level, allowing the operator to hold his/her head in the neutral position shown in the diagram.

The display monitor should be positioned so that the distance from the eye to the screen can be adjusted, allowing the centre of the screen to be positioned so viewing angle is 5 to 20 degrees below eye level. Display monitors placed too low will increase musculoskeletal tension and fatigue to the back and neck. Display monitors placed too high will also increase visual fatigue and neck tension. The screen should be detached from the keyboard so that each can be positioned in an optimum manner.

General lighting for the office varies between operators. Light above and behind the display monitor will glare onto the screen. Reduced glare onto the screen by appropriate placement of the display screen in the room. The workstation should be oriented so the operator does not face an unshielded window or a bright light source. The orientation of the monitor screen should be perpendicular or nearly perpendicular to the line of windows.

The screen should be tilt able to help eliminate screen reflections. Reduce mirror-like reflections on the screen by using etched screen surface, a thin-film coating, or a hood. Other types of reflections on the screen can be reduced by using a neutral density, micro-mesh, or glare-resistant filter.

For any further advice or information on ergonomics, please contact the Clinic on 01273 835116 or

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