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Risk Factors and Sources of Injury > Improper Monitor Position          
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Graphic of Ergonomic Considerations When Setting
            Up a Sitting WorkstationImproper Monitor Position

What is the Correct Location (Height and Distance) to Position the Monitor?

The monitor should be located directly in front of the user (i.e. inline) when typing with the top of viewing surface of the monitor at or below eye level. The monitor should be located at least 18" and no more than 36" from the eyes; if uncertain, place it a distance equal to the size of the monitor (i.e. if a 24" wide monitor is being used, it should be located at least 24" from the eyes of the user when normally seated). 

Why is Improper Monitor Position a Risk Factor?

If the monitor is too low or too high, neck strain or back strain will likely occur as the user attempts to 'lean' back or forward to see the the viewable area on the monitor. When the monitor is at a lower elevation, the eyes of the user will be drawn downward. When this occurs, even slightly, the head will have an automatic tendency to tilt downward, putting strain on the neck muscles. Over time the entire body will lean forward subconsciously to relieve the tension on the neck.

A normal relaxed position for the head is anywhere from completely vertical up to as much as 10° looking downward - any 'tilt' larger than that can lead to the issues noted above.
 
If the monitor is too far away, the user is forced to lean forward to see text or fine detail on the monitor.  This can lead to eye strain, and stress on the back as the user leans forward (losing their back / lumbar support) to identify material on the monitor.

If the monitor is too close, the user is forced to lean back or move their chair away from the workstation to prevent issues with focal length (i.e. convergence or the ability to focus), which can make the keyboard, mouse and reference materials more awkward to reach.

How Far from the Optimal Position does a Monitor have to be to avoid it being a Risk Factor?


For most individuals, the eyes can accommodate a height variance without too much effort of approximately 5° which translates over an 18" distance to 1.5", and a horizontal variance of approximately 15° which translates over an 18" distance to 5".  However, the problem is that most individuals will tend to achieve this movement with their neck as opposed to their eyes, and as this is a subconscious action, it can be a difficult one to actively prevent from occurring. 
 
What are the Symptoms of a Monitor which is in the Wrong Position?


Symptoms that indicate that the monitor is at an improper height are aches, fatigue and pain primarily in the neck but also potentially in the back.

Do Users with Bifocal Glasses have Different Considerations when Positioning the Monitor?


As the bottom half of bifocals are normally used for reading and near focus targets, the ideal location of the monitor is substantially lower to ensure the same position at the neck.  The monitor should be located at a height that will allow the user to maintain their head at a comfortable vertical position which does not go beyond 90° (i.e. tilting the head skyward).  This will result in a lower elevation of the monitor than for individuals without bifocals.

One option is to put an LCD monitor on an articulating arm and adjust it at a 45° angle so that the bottom of the monitor is just above the keyboard (likely hanging slightly over the front edge of the desk).  An alternate strategy for wearers of bifocals is to use a separate pair of reading glasses when working at the computer.  In this case, the 'regular' ergonomic recommendations apply without a need to modify the workstation.

Why Reading from a Piece of Paper is not the Same as Viewing a Monitor?

Some individuals might be inclined to think that the head is typically significantly inclined when reading papers, the same posture should hold for viewing monitors.  This position is flawed on several fronts.  The reason paper is typically read at a lower elevation stems from biomechanics.  Human arms are not designed to maintain an extended position for any period of time at or near shoulder height.  Lactic acid will build up almost immediately upon the extension of arms.  It is far more comfortable to hold any object with arms relaxed at the sides and bent at the elbow.  When viewing a monitor, the arms are not involved, making the comparison inappropriate at best.

Humans act and react to their environment from a vertical position, walking on two legs and sitting in an upright position.  Hunting ancestors and modern day human pedestrians default to scanning the horizon to ensure that they are safe.    A more practical example is that the 'prime' location in grocery stores for product placement is at a height of 48 - 60" off the ground for these same reasons. 

How can the Choice of Accessories or Workstation Help to Reduce Improper Monitor Position?


The addition of an LCD Monitor Arm is the best addition to a workstation design to ensure correct monitor positioning.  Other alternatives include Adjustable Height Desks and Monitor Risers.

What Other Strategies can be used to Address Improper Monitor Position?

Consider the possibility of adding a second monitor to the workstation, as this may sometimes alleviate demands placed on the user by a single monitor solution.

 

Last edited December 16th, 2013

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