A few weeks ago I came across the following issue in one of our ergonomists’ reports. As it can definitely be a common issue with eyestrain, I thought I’d share it with everyone. I’ve taken most of the text directly from the report as written by our ergonomist, Kirsten Willms.

The client (we’ll call her Ms. Smith) was experiencing various types of discomfort while at her workstation, particularly eyestrain. The EWI ergonomist conducted an assessment and noted several changes that would help Ms. Smith work more comfortably. With regards to the eyestrain, one of the causes was the high light levels at her face when she faced the computer.

Ms. Smith’s desk was oriented so that she partially faced an uncovered window. Though the window was treated with an anti-reflection coating, the light levels at her desk were higher than the levels recommended by the CSA Office Ergonomics standard (CSA Z-412). The light hitting Ms. Smith’s desk was measured at 350 lux. However, the light at her face while facing her computer was 750 lux, much higher than the recommended 300-500 lux.  These high light levels were most likely contributing to her eyestrain symptoms.  Ms. Smith has had an extended monitor arm installed so that she can move her monitor more perpendicular to the window, however the layout of her desk (split surface corner unit) does not allow her to rotate her keyboard and mouse accordingly.  The following recommendations were recommended for their feasibility in order to reduce the amount of light reaching Ms. Smith’s face:

1. The preferred solution is to install a mesh roller blind on the lower window adjacent to Ms. Smith’s desk.  This would allow some light to filter through while reducing the overall light levels.
2. Consider an alternate screening device, such as the mesh “leaf” available at Ikea which could be placed in front of the window to filter light.
3. Create a screen using plants on the window sill.
4. Place a poster or bulletin board over the window.  This option however will completely block the light from the lower window.
5. Alternatively, the location of Ms. Smith’s computer can be moved to her left side table.  This would involve the relocation of her CPU, bracket, storage panel, and storage pedestal, and preferably a user height-adjustable work surface should be installed.

While some people find there is not enough light, it is definitely possible to have too much! Check the lighting levels in your workplace so your staff can work more comfortably.

This blog is from research that Linda has been conducting for her Doctorate in Occupational Therapy. Linda wrote the following blog based on her research on AMD – Age Related Macular Degeneration.

Age-related macular degeneration (AMD) is a disease that can be part of aging.  AMD affects how sharp vision is and it specifically affects central vision.  Central vision is important for activities such as reading and driving, where it is important to see an object clearly.

AMD affects a structure known as the macula in the eye as shown in the figure of a cross section of an eye below.  The macula allows us to see fine detail. 

In some cases, AMD advances slowly.  In this case, an individual may not even notice change to their vision.  In other people, the disease occurs quickly and leads to vision loss in both eyes.

What is Dry AMD?

There are two forms of AMD – wet and dry.  Wet AMD is responsible for severe vision loss that occurs quickly.  We are going to focus on dry AMD.  Dry AMD occurs when light -sensitive cells in the eye slowly break down.  Over time, central vision blurs in the affected eye.  You can have trouble recognizing faces or reading.

Let’s look at Dry AMD in a bit more detail.

Under the retina, yellow deposits can develop known as drusen.  Drusen are found in people over the age of 60.  If you have drusen, it does not mean you have AMD.  Scientists are even unsure how drusen are associated with AMD, but if they increase in size or number it raises the risk of developing dry AMD or wet AMD.  There are three stages of Dry AMD.

Three Stages of Dry AMD:

1)    Early AMD – no symptoms or loss of vision, but several small drusen or a few medium sized drusen are detected.

2)    Intermediate AMD – many medium sized drusen or one or more large drusen are detected.  In some cases, individuals see a blurred spot in the center of their vision.  Individuals may need more light for reading or other tasks.

3)    Advanced Dry AMD - individuals not only have drusen, but they have a breakdown of light sensitive cells and tissue supporting the central retinal area.  Breakdown of this area can result in a blurred spot in the center of vision.  If left untreated, it can get bigger and darker.  You can have trouble recognizing faces, as shown in the next figure (CNIB, 2006). 

Treatment for AMD:

At the current time, there is no cure for AMD, but there is a treatment to delay and possibly prevent intermediate AMD from moving to the advanced dry AMD.

High dose mixtures of antioxidants and zinc can significantly reduce the risk of advanced dry AMD which is associated with vision loss.  See your physician.

Remember, it is important to have your vision checked regularly at least every year!

References:

CNIB website: http://www.cnib.ca/en/your-eyes/eye-conditions/amd/Default.aspx

National Eye Institute: http://www.nei.nih.gov/

Last week I discussed an assessment that was conducted on a control panel for workers at a manufacturing plant. The control board was large, causing reaching for controls, awkward postures of the trunk and neck to see around or over the control board and it did not provide room to sit comfortably.

Here are the recommendations that our ergonomist made:

Investigate the feasibility of modifications to the control panel to enable greater adjustability and subsequently minimize awkward postures. The following design goals are recommended:

1.  
   1. Minimize forward and above shoulder reach for frequently-used controls
   2. Minimize leaning forward in the seat; enable Operators to sit back in the chair in a neutral, supported posture.
   3. Improve clearance beneath the panel and support for the legs and feet when seated.

 To achieve these design goals, the following options may be considered:

1.  
   1. Investigate the feasibility of repositioning frequently used controls toward the bottom of the panel. If no further changes are made to the panel arm, this would minimally help to reduce some of the awkward postures associated with reaching for the controls.
   2. In combination with the above recommendation, investigate the feasibility of installing a mechanism to enable height adjustability within the control panel to better accommodate the range of statures with the Operators. In particular, height adjustability would enable Operators to position the panel to minimize above shoulder reaching and to improve clearance beneath the panel for the legs when seated.
   3. Investigate the feasibility of reducing the size of the control panel, including height, width and depth. The size of the panel, and in particular the depth, presently limits the effectiveness of the above recommendations. For example, the depth of the panel will limit the amount of clearance a worker has to put his/her legs under the panel regardless of the height that the panel is set at. Tilting the panel into an upright position is not recommended since it may potentially introduce concerns associated with pressing and operating the controls, as well as impairing line of sight to the surrounding machinery.

 Once a final decision is made on the above options, EWI always offers to assist in providing specific design criteria.  In this case, we recommend a follow up consultation to assist with the specifics in the positioning of the panel, based on worker anthropometry and the nature of the tasks.

 In addition to modifications of the control panel, the following were also suggested:

1.  
   1. Reduce requirement to look at bars moving downstream from the control panel. The ergonomist suggested using a computer monitor instead to reduce having to peer over the panel and producing an awkward posture.
   2. Rotation of workers every 4 hours if standing to use panel. In this case, the company does already have shift rotation in place.
   3. Ergonomic training for the employees – the ergo training should teach the workers how to reduce risks through taking micro breaks, perform work break stretches and adapt proper body positions when working, learn to identify MSI symptoms and report them to a supervisor.

Ergonomics isn’t just about the office – it is also valuable in reducing the risks for musculoskeletal injuries in industrial environments. EWI Works has extensive experience in industries such as mining, utilities, forestry, food production, and manufacturing plants. EWI consultants have conducted assessments on assembly line workers, meter readers and in a recently, reducing MSI risks in control operators.

The client is involved in steel production. At the workstation requiring an assessment, cooled bars of steel are cut as they arrive along a conveyor where the Operator uses a control panel to manually operate the  shear. The control panel consists of several manually operated controls used for every cut and is suspended by a semi-fixed overhead hoist and boom. During operation, the Operator needs to be able to watch the upstream conveyor, as well as downstream after the cut is made. Operators may choose to either sit or stand, or both, throughout their turn at the panel.

The operators are rotated every four hours at this station. Over this time, our ergonomist noted the following awkward postures that were deemed moderate risks for MSIs:

• Excessive reaches
• Bent/tilted head and neck
• Leaning forward or sideways
• Twisting the back

These risks are mainly caused by both the panel design and the Operators’ work practices. The following is an excerpt from the ergonomist’s report to describe the causes of the risks:

• Panel design: The panel is semi-fixed and can be turned and swivelled left to right but cannot adjust in height or angle to accommodate a variety of employee statures. As a result, the controls near the top of the panel tend to be at a reach, especially when in a seated posture. This reach is increased further due to the inability to adjust the height of the panel. Workers are generally unable to position the chair with the legs under the panel, due to the overall size of the panel, which is 30″ (H) by 30″ (W) by 13″ (D). The depth particularly creates an inability to position the legs underneath the panel when seated. Therefore, the Operators must sit further away, leading to an increased reach as well.
  • The Operator needs to be able to look into the shear to examine the bars. Depending on the location of the panel relative to the Operator’s position, the Operator may be tilting their head/neck to the side to view around the panel. The panel itself is large and not adjustable and impedes view of the shear (upstream and downstream) from a seated position.
  • The Operators also needed to turn to look far upstream on the conveyor to examine the bars prior to arriving to the shear. The Operators have to stand semi-perched on a footstool to raise themselves higher to gain a better view.
• Position of controls on the panel: Controls used most often are positioned near the top of the panel, which leads to frequent reaching.

 Next time, I’ll discuss some of the recommendations the EWI ergonomist made to help reduce the risks for MSIs.

In researching the iPad, I discovered there is a lot of negativity toward the product, particularly the ergonomic aspects. In general, the most common complaints were:

• 1. weight – heavier than a hand held
• 2. portability – bigger than an iPod or other similar device – smaller than a laptop.
• 3. viewing angle – needs to be held up or propped up. This can either cause strain on the hands and arms to hold it at an angle where the screen can be viewed properly or requires a poor sitting posture where the neck is bent, causing strain. Apple’s answer was a dock – which leads to a portability issue in itself.
• 4. typing – difficult to input data without the Apple keyboard attachment

While the above issues seem to be the most common complaint on a lot of blogs and product reviews, one must keep in mind that a product’s benefits depends on what you are using it for. Laptops, for example, are still not a replacement for a regular computer that comes equipped with a separate monitor, keyboard and mouse. Working an 8 hour day on a regular laptop will also result in discomfort to the user.

So what is the actual intention of the iPad? Certainly, it isn’t meant to replace the laptop or a computer. It’s a handy device but has Apple claimed that it is the answer to bulky laptops or non-portable computers when typing an office report or college essay? It’s intention, maybe the fault of Apple marketing and advertising or perhaps it’s target market’s comprehension of what the iPad is meant to do,  is a little misunderstood.

Let’s look at the actual functions of the iPad. Apple does not say “perfect for working on office projects while you are on a plane to Mexico.” The direct quote from the website says “The best way to experience the web, email, photos, and video. Hands down.” The iPad is a larger version of the iTouch or iPhone – and I would rather check my email on the iPad’s larger screen than on my teeny iPhone screen! It really isn’t any different than holding a large hardcover book. Another use is one that our very own Linda Miller came up with – it can easily replace the clipboard and paper when making notes or filling in a check sheet when conducting an assessment and then transferring it to your computer workstation.

If your intent is to replace your laptop or home computer, you best buy the accessories to make it more ergonomically sound. It will need the docking station for reading a book or even reviewing reports. It could also use a separate keyboard if you plan on actually typing your Philosophy 101 final essay in Starbucks. Remember, even a laptop isn’t meant for prolonged use without using peripherals.