Just as a workstation or assembly line needs to consider workers of different heights and statures, an office must also consider the individual lighting needs in an office that houses several desks or cubicles. The CSA Z-412 Guideline of Office Ergonomics indicates a target lighting level of 300 to 500lux based on the level of computer use, however variety individual needs and tasks being performed in an open office design require some flexibility.

To give a basic idea of the lighting changes, half of the overhead fixtures had the bulbs removed in a scattered pattern to attempt to distribute the light equally throughout the office while still allowing sufficient lighting at the individual workstations. The window coverings, task lighting and workstation locations did not change.

Light measures were taken on the desk surface between the keyboard and monitor (a primary work point) both before and after the overhead lighting changes with window shades fully open, shaded, or fully closed. Taking the measurements with just the overhead lighting showed a reduction to 290 to 370lux. With the blinds open, the light levels were very high, particularly at the workstations closest to the window. With the blinds shaded, the light levels were lover but not low enough to meet the recommended range.

A survey was also conducted, where the employees were asked some basic demographic information, visual information (use of glasses, light sensitivity) and their level of happiness with the lighting pre and post change. In general, the staff went from somewhat happy/happy to happy and very happy. Some of the concerns noted were 1) the brightness caused by reflection of snow on the ground, 2) brightness of the sunlight and 3) the task lighting is too focused when the overhead lights are off.

So what were the recommendations? Again, taking into consideration the light levels were different depending on the workstation location and individual needs, some of the short term suggestions were:

• Return some of the overhead bulbs to increase light levels at certain workstations.
• Utilize the window shades during periods of the day where it’s brightest or glare from the snow might be a concern.
• Ensure task lighting isn’t shone directly onto monitors or this might produce unwanted glare. When not needed, task lighting should be turned off.

Long term, the consultant recommended replacing the window shades with ones with better control over the amount of lighting entering the office area, but that are not a source of glare itself.

If varying light levels are an issue in your office, give us a call: 780-436-0024.

In the first part of this two part series, I discussed an assessment that was conducted on a laboratory worker at a microscope bench. The issue is that although the assessment was to be conducted for one individual, there are other individuals working at this same workstation during different shifts. Therefore, solutions needed to consider the possibility of other individuals of varying sizes working at the same station. There are a number of individual solutions, that when combined, may result in a larger overall impact.

• Provide chairs with a greater height range, along with other adjustable features such as a sliding seat pan to accommodate varying upper leg length. When the height difference between the elbow position and the microscope control position can be minimized, the employee will achieve a better fit with the workstation.
• If needing to sit higher, employees will require the use of a foot stool to support the legs and feet. Although there are a variety of footstools available during the evening shift, there may be limited availability or options on the day shift.
• Better positioning when using the computer may require examining several options:
  • Investigate the feasibility of alternative software or input controls that would minimize the need to perform traditional typing and mousing. Examine software or hardware options that would minimize the need to use two hands to type (thus reducing the need to completely turn the body) as well as improving efficiency (i.e. cut down on keystokes). Alternative software may include voice recognition, however it is strongly recommended that this solution undergoes a trial period to evaluate the effectiveness as well as potential concerns (e.g. impact of environmental noise, impact to individuals who use vocal chords for greater duration).
  • The space on the work surface is limited in part by the presence of shelving along the middle of the microscope bench. This limits where the PCs are positioned, which in turn limits where the monitor and keyboard/mouse can be positioned. Overall, there is limited flexibility in which to individually set up the workstation. Solutions may include examining alternative shelving options or design (e.g. one vertical shelf at the end of the bench, narrower shelves), alternative PC locations (e.g. beneath the work surface), the use of monitor arms, and/or potential millwork changes to the work benches (e.g. increased desk depth). In addition, replacement of the work benches is an option (e.g. height adjustable work benches), although potentially a more costly alternative.
• Due to the potential complexity of these changes, it was recommended that the organization consider a design review of the bench that could lead to the development of a prototype workstation. Long term, this may have impact to other departments as well where microscope work is also performed.

The laboratory bench is one scenario where many individuals might share one workstation. EWI Works has also encountered this situation in factories or food processing plants. If this sounds like your organization, contact us to get some ergonomic advice on a multi-user workstation.

Often, workers in a laboratory setting share a workstation, particularly when working different shifts. When requested to conduct an assessment of a workstation for an individual, an ergonomist also has to keep in mind that recommendations must consider other individuals of varying size and stature who will be conducting the same tasks at that workstation. In the following case, an assessment was conducted on a lab technologist at a microscope bench.

The assessment included evaluation of physical work tasks and work station layout as they related to the worker’s size, stature and physical restrictions. The ergonomic assessment included observation, interview, task analysis and physical measurement of the work place to determine the level of risk associated with performing microscope duties. The tasks involved with these duties include examining a specimen, sometimes recording it on paper next to the microscope and then entering the data on the computer later or pausing to enter the data on the computer in the middle of viewing the specimen. A tray of specimens usually takes 30 minutes to an hour to examine – 2 to 5 minutes each.

It was concluded that risks for the microscope bench, existed for the hand/wrists/arms, back/torso and shoulder/neck. A moderate risk exists for the legs/feet and head/eyes and recommendations were provided. 

However, since this work bench is shared by several employees performing different duties on day and evening shifts, it is difficult to recommend design changes without knowing the full extent of their impact on other employees. The findings of the assessment were consistent with other assessments with regards 1) to the working height requirement of the microscope and the height limitation of the regular chairs, 2) the use of the computer intermittently with keyboard/mouse use, 3) the presence of the metal trim beneath the work surface that contacts the thighs and limits the sitting height range of the user relative to the microscope.

Tomorrow, find out some solutions to this common problem in many workplaces.