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Workstation Monitor and Document

Monitor and document placement is important in creating a comfortable workstation. Consider the following items in order to reduce awkward head and neck postures, fatigue and/or headaches:-


Display	Source Document Position

Display

The monitor and document are related to the placement of the keyboard, mouse, and properly adjusted chair.

A display screen that is too high, too low, or placed to the side of the user (Fig. 1), may, over time, cause awkward postures and increased stress on the muscles of the neck, shoulders, and upper back.

Fig. 1 Display screen too low

Keep monitor directly in front of the user. The topmost line of the screen should not be higher than the user's eyes. Screens that swivel horizontally and tilt or elevate vertically enable the operator to select a comfortable viewing angle

Fig. 2 Comfortable viewing
angle

The preferred viewing distance is 18 to 24 inches. If there is not enough table depth to accommodate this distance, install a keyboard extender or tray underneath the desk (Fig. 3). The table depth should generally be at least 30 inches from the wall to properly accommodate monitors.

Fig. 1 Display screen too low

Rest eyes periodically by focusing on an object at least 20 feet away.
Stop, look away, blink and/or stretch at regular intervals.
Expand the employee's duties with other non-computer tasks such as filing, phone work, or customer interaction to provide periods of rest for the eyes.


Source Document Position

Fig. 4 Screen and document holder are close together and same distance from the eye	Fig. 5 In-line document holder that allows for writing.	The screen and document holder should be close enough together so the operator can look from one to the other without excessive movement of the head, neck or back (Fig. 4) If writing needs to be performed, a document holder can be positioned directly beneath the monitor (Fig. 5). This provides a sturdy writing surface and prevents frequent movement of the head, neck or back.

Workstation - Chair

A properly designed and adjusted chair will provide appropriate support to the back, legs, buttocks and arms. This support can reduce contact stress, over exertion and fatigue. It will also promote proper circulation to the extremities. The following items are critical to an employee who spends extended hours at the workstation: -


Seat Position	Chair Height	Armrest

Seat Position

Fig: 1 Adjustable chair
and backrest. Seatpan
with rounded, "waterfall"
edge

The seat and backrest of the chair should support a comfortable posture that allows frequent changing of the seating position (Fig. 1). The seatpan should be padded and have a rounded, "waterfall" edge (Fig. 1). This will reduce contact stress to the back of the legs. The angle of the seatpan is also important. A seatpan with an adjustable tilt ensures the worker is able to maintain proper support in different positions.


Chair Height

Fig. 3 Knee slightly higher than the seat of the chair.	Fig. 2 Footrest	Chairs should be height adjustable. The chair height is correct when the entire sole of the foot can rest on the floor or a footrest and the back of the knee is slightly higher than the seat of the chair. This position allows blood to circulate freely in the legs and feet.


Armrest

Fig. 4 Office chair with adjustable armrests.	Adjustable armrests (Fig. 4) can be lowered to fit under work surfaces. This allows the user to work from a comfortable distance. The armrests should support both forearms while the employee performs tasks and should not interfere with movement.

Workstation - Keyboard and Mouse

The proper position of the keyboard and mouse is essential in creating a comfortable workstation.


Height and Orientation	Placement	Design and Use

Height and Orientation

Fig. 1 Keyboard tray.

The work surface may need to be raised or lowered to keep the operator's arms in a comfortable position. This can be achieved by installing an adjustable keyboard extender or tray (Fig. 1), by providing an adjustable table/working surface, or by raising the chair and providing a footrest if needed.

Adjust the keyboard and/or chair height so the employee's elbows can hang comfortably at the side of the body, the shoulders are relaxed and the wrist is not bent up or down or to either side during keyboard use.

The angle of the keyboard should also be considered when determining the preferred height. The preferred working position for most keyboard operators is with the forearms parallel to the floor and elbows at the sides; this allows the hands to move easily over the keyboard.


Placement

Fig. 2 Mouse placed too far from the body.	Fig. 3 Mouse placed close to the body.	A keyboard or mouse that is not directly in front of or close to the body (Fig. 2) forces the employee to repeatedly reach during use. Make sure the keyboard is placed directly in front of the user. The mouse should be positioned at the operator's side with his or her arm close to the body (Fig. 3). A straight line should be aintained between the hand and the forearm. The upper arm should not be elevated or extended while using the mouse. The employee should not have to reach to use the mouse.


Design and Use

Fig. 2 Mouse placed too far from the body.	Fig. 3 Mouse placed close to the body.	A keyboard or mouse that is not directly in front of or close to the body (Fig. 2) forces the employee to repeatedly reach during use. Make sure the keyboard is placed directly in front of the user. The mouse should be positioned at the operator's side with his or her arm close to the body (Fig. 3). A straight line should be aintained between the hand and the forearm. The upper arm should not be elevated or extended while using the mouse. The employee should not have to reach to use the mouse.