The past 22 months has brought on some interesting and new injuries for many of you since your work stations have changed. More of you are using computers and sitting far more than you have ever before. Improper work stations can put strain on many parts of the body, including your neck, low back, wrists and even strain your eyes. Now that many of you may be working from home again, I thought it would be a good ideato review some basic office ergonomic components that you can include in your home office setup.
There are many components to your office setup to consider. I will summarize the most common components that have been taken from the Canadian Centre for Occupational Safety website that can be found here.
Computer glasses: For those of us with aging eyes, monitor spacing can largely affect our eyesight. As we get past the age of 40, we begin to see changes in reading or seeing objects close to us. This is the time when one may start wearing bifocals. A computer screen falls into that in between distance, not so far away, but also not likely 6-12” from our face. Using bifocals while on the computer can create some neck discomfort as the tendency is to tilt the head back to position the bifocal lens in the proper sight line to view the screen clearly. Because the screen is a little further out then the bifocal range, the tendency will be to lean forward, thus creating more postural distortions, musculoskeletal tightness, headaches, and the list goes on. If this is the case, you may be suffering from computer monitor syndrome and may need a more specific pair of glasses to account for the distance of the computer screen from your eye. Speak with your eye specialist if you are having eye strain, vision problems or other head and neck symptoms to discuss adjusting or adding to your current eye prescription. There are also other factors that may contribute to eye strain, like contrast and monitor colour which your eye specialist can assess.
Monitor placement: When we consider the placement of the monitor, there are two factors which need to be considered, the viewing angle and the viewing distance.
The viewing angle is defined as the angle above or below the horizontal sight line of the viewer to the centre of the object that they are viewing, in this case the computer monitor. A poor angle can lead to neck and shoulder strain. Researchers agree that the eyes naturally have a straight forward and slightly downward eye cast. The exact angle of downward cast is reported to be in the range of 15-30 degrees. When the eyes look upwards above the horizontal line, the eyes will become fatigued. This does not seem to be the case when looking downwards below 30 degrees, and thus some researchers have added another acceptable 15 degrees to the limits of downward gaze.
The viewing distance is defined as the space between the viewer and the object being viewed, again in this case the computer monitor. The closer the object, or the shorter viewing distance, can lead to eyestrain. Viewing objects farther away don’t tend to lead to eyestrain, but can change the sharpness of the image. Our eyes use the actions of accommodation and convergence to view objects close to us. The eyes accommodate or adjust, to a closer object to keep it in focus by changing the shape of the lens inside the eye. The action of convergence is the inward turning of the eyes (towards the nose) to focus on an image. When the eyes have to focus on closer objects for prolonged periods of time, eyestrain will occur because it requires more muscular action to maintain focus. Each of us will have a resting point of accommodation and a resting point of vergence, which is the distance where our eyes (if 20/20 vision or properly corrected vision) will not experience eyestrain. Researchers have given a range of 40-70 cm of viewing distance where the majority of us will not experience eyestrain. If there are constraints in space or the distance is too great to see images or text clearly, it is recommended to increase the font size or zoom in instead of creating a shorter viewing distance.
Ergonomic chairs: A chair becomes ergonomic when it fits the operator in terms of body size and workstation use; and meets the requirements to perform the tasks of the work. There are several features to chairs which should be considered. These include:
- Seat height range
- Back rest
- Seat height depth
- Seat width
- Seat angle
- Seat surface
We should also consider the desk height or workstation at which chair will be located and the type of flooring.
The operator of the chair also needs to be able to easily adjust all of the features of the chair from a seated position. When purchasing a new chair, look at several suitable chairs and try them out, as what may be great for one, doesn’t mean it will be great for another with different needs.
Keyboard and Mouse: There is no correct placement of a keyboard or mouse, but rather, a workstation that doesn’t cause excessive reaching or leaning of the body causing discomfort. While using a mouse, one should maintain the wrists inline with their shoulders.
The mouse placement to the side of a large keyboard may lead to too much wrist lateral deviation or reach that requires more shoulder muscle tension and use.
When this is the case, switching to a smaller keyboard that doesn’t have the number pad on the right side may prevent the excessive wrist deviation or reach. The use of a mouse platform and wrist support may also be used to help to maintain the wrist in a more supported and proper position. Another option could include placing the mouse in between the keyboard and the operator to make use more comfortable and safe.
Sit/Stand desks: Many office workers are moving towards a sit/stand desk to vary their position throughout the workday. Here are some considerations when setting up your sit/stand desk.
Maintain a neutral body position when both sitting and standing:
- Hands, wrists, and forearms are straight, in-line and roughly parallel to the floor.
- Head is level or bent slightly forward, forward facing, and balanced. Generally speaking, the head is in-line with the torso.
- Erect or upright spine.
- Shoulders are relaxed and upper arms hang normally at the side of the body.
- Elbows stay close to the body and are bent between 90 and 120 degrees.
- No twisting of the upper torso.
- The in-line sight is between the horizontal and 30 degrees below the horizontal (i.e., when viewing the monitor, the monitor is at eye level or slightly below eye level).
When standing, also consider:
- The platform height is approximately at your standing elbow position (e.g., your arms are in the same position as they would be if you were sitting).
- The keyboard and mouse are aligned as you would when you are sitting.
- The height of the monitor should still be between horizontal and 30 degrees below.
- Wear supportive footwear.
- Consider the use of an anti-fatigue mat, where appropriate.
- Use a footrest when standing to help shift your weight as needed, or shift your weight from leg to leg occasionally.
- Make sure that any cables, electrical access, storage of materials, and general layout do not make adjusting the desk difficult.
For further and more detailed information on the above ergonomic recommendations, please refer to the Canadian Centre for Occupational Health and Safety.
If you require any further help with home office setup or related injuries, please be sure to discuss with us or book an appointment online by clicking here.