Environmental Health & Safety

Workstation Configuration

1. With the operator standing, measure from the floor to the upper edge of the operator's kneecap. This will determine the height range of the task chair seat pan necessary to support the operator in a declined (forward-tilt) configuration. If the chair does not feature a forward-tilting seat pan, then make sure that the seat pan height range will allow the operator to sit with their legs parallel to the floor.
2. With the operator seated, measure from the back of their knee to their buttock. This will be used to determine the proper seat pan depth of the chair which should provide a comfortable space between the front of the seat pan and the back of the operator's knee. The seat pan depth should not exceed the popliteal-buttock measurement of the operator, though it can can be up to two inches shorter. It is important to ensure that the seat pan of the chair does not press against the back of the operator's knee.
3. With the operator comfortably seated in their preferred sitting posture, have them relax their arm at their side, then bend at the elbow ninety degrees. Measure from the floor to their elbow. This will be used to determine the height of the operator's worksurface.
4. With the operator comfortably seated, measure from the floor to the operator's eyebrow. This will be used to determine the height of the operator's monitor.

Having taken the necessary anthropometric measurements of the operator, the workstation can be properly configured as explained below. These are guidelines only and there are exceptions. The objective is to facilitate a comfortable posture. If there are concerns that this guideline is not sufficient on an individual basis, contact Environmental Health and Safety for assistance.

1. The operator is seated in an appropriate chair which is correctly adjusted to their preferred sitting posture, and their feet are comfortably resting on the floor.
2. The worksurface is set to within one inch of the height of the operator's elbow from the floor.
3. The monitor should be placed as far away as possible with the operator still being able to read it clearly. This is because longer distances relax the eyes. The height of the monitor should promote a comfortable posture of the head and neck. A good starting point is to place the upper edge of the display within an inch of the operator's eye level. This should bring their natural line of sight to fall on the the lower part of the upper third of the display. If the operator feels that they are holding their head and neck extended backward or flexed forward to view their display, the monitor should be lowered or raised accordingly. People who wear bifocals will likely need to have their monitor set lower. If the operator uses eyewear at their workstation, they should consider consulting with their medical care provider about eyewear specific for use at a video display terminal.
4. If the operator frequently transfers information from documents to their computer, placing a copyholder in line with their display can reduce strain associated with flexing or twisting their head and neck.
5. An appropriate adjustable keyboard tray with a negative tilt feature can be used to optimize the position of the mouse and keyboard, further reducing strain. If moderate computer use is required of the operator for more than four hours per day, and the operator is a touch typist, an adjustable keyboard tray is recommended.
6. The operator should have adequate clearance beneath their worksurface to be able to move freely and avoid awkward postures.

For operators who prefer to sit-up at their workstation, using a traditional task chair in the declined posture is recommended. The same guidelines will apply. The main difference is: The declined posture will further raise the operator from the floor, so the worksurface will need to be set higher to provide the proper support.