The other day I was asked to present an Ergonomic Seminar and complete Individual Workstation Assessments to a small - medium sized workplace in response to increased anecdotal reports from workers of back pain and general discomfort caused from sitting at desks for prolonged periods of time.
The seminar commenced by discussing with the workers the meaning of ergonomics and how it related to them. Galer (1987) describes ergonomics as optimizing the “fit” between the user and machine or system. With this premise in mind, it helped the organization work with the equipment currently in place, and not feel compelled to rush out and purchase the next great ergonomic “thing”.
One in three workers that day reported generic back pain, of a non-specific cause. Literature supports that these workers I saw are not alone; Griffiths et al (2012) found that over a 12-month period 60% of people in their study (total 934) experiences back symptoms.
When conducting the one to one workstation assessments the most common “error in workstation set up” I saw related to positioning of the monitor. Observation of the workers revealed many were sitting forward on their office chairs to be able to comfortably focus on the data on the monitor, and therefore not utilizing the postural supports of the desk chairs. The prolonged leaning forward, to be able to read the monitor was causing muscle fatigue in lower back, neck and shoulders.
Many factors influence the “correct” distance of the monitor from the worker, including age, whether or not a person wears glasses, height of the monitor and image displayed on the screen. The Ergonomics Unit at Worksafe Victoria have developed Officewise - a Guide to Health and Safety in the Office (can be downloaded here), in this resource the following recommendations are made to optimize the fit between the worker and the monitor positioning:
Distance from the monitor: is recommended to be approximately one full arm-length when the worker is sitting in their usual position for keying.
Height of monitor: should be positioned so that the top of the screen is level with, or slightly lower than the workers eyes when sitting upright. At this height awkward neck positioning and strain can be mostly avoided, and normal curvature of the neck can be maintained.
Positioning of screen: it is recommended that the screen be placed in front of the worker to minimize glare or reflections.
There were times where these guidelines were used just as that, guidelines, for example workers wearing multifocal lenses found that the monitor needed to be lower to avoid tilting the head backwards.
However once these relatively simple changes were made to the position of the computer monitor, workers found themselves sitting back in their chairs and immediately noticed improved levels of comfort and reduce muscle soreness.