Computer Basics: Ergonomics
Ergonomics is the study of the relationship between the worker and the job and looks at adjusting the work environment to improve your comfort and safety while you do your job. There are a number of factors that ergonomics considers, including:
- body posture & movement e.g.
- sitting
- standing
- lifting
- pulling and pushing
- environmental factors e.g.
- noise
- lighting
- temperature
These days a lot of research in ergonomics looks at computer use, as a lot of people use computers as part of their jobs and sitting & staring at a screen all day isn't really good for you. Increasingly, we use computers and other devices (especially smartphones) for leisure as well as business and ergonomic principles can be applied to all computer use, not just for work.
Computers are good, but you can have too much of a good thing. There are some common health problems associated with repeated computer use:
- staring at a computer screen too long - tired eyes, headaches, poor sleep
- working with keyboard and mouse - sprains (dislocation) / RSI (Repetitive Strain Injury)
- seating and posture - back and joint pain, problems with the spine.
When you're driving a car, you make sure that the seat is adjusted so that you're comfortable and can reach the steering wheel and pedals, so you should make sure that when you're using a computer, you take the time to adjust everything to your satisfaction.
Here are some tips to help avoid health issues:
Monitors/Screens
- A monitor should be at least 20cm - an arm's length - away from your face
- The monitor should also be placed directly in front of you, not slightly to the side of your sitting position
- Most people find it more comfortable to look slightly down at a computer monitor, rather than straight ahead. The top of the monitor should be at, or just below, eye level
- Some people recommend the 20/20/20 rule; every 20 minutes using a screen you should try to look away at something that is 20 feet away from you for a total of 20 seconds. This should reduce eye strain.
- Move monitor away from light sources to reduce glare
- Think about getting an anti-glare screen
- If your monitor has adjustable display settings, then adjust the colour "temperature" to reduce blue colours (blue colours on a screen are more closely linked to eye strain than other colours)
- Try to match your screen brightness to your surroundings - if your screen is too bright or too dark relative to the surroundings, it can place extra strain on your eyes by having to repeatedly adjust to different light intensity
- Try to avoid sitting in front of a window or other strong light source
- Stop using devices 30 minutes before going to bed
Keyboard/Mouse
- Don't hunch over your keyboard - sit up straight
- Have your keyboard positioned in front of you and your mouse to the side of the keyboard
- The keyboard and mouse should be at elbow and forearm height
- Position your keyboard and mouse near the front of the desk so that you're not stretching to use them
- Don't rest your wrists on the desk when you're typing (this means your hands will be above your wrists, putting extra strain on your wrists
- Avoid using a wrist rest, unless you rest the heel or palm of your hand on it, not the wrist (maybe it should be called a palm rest in that case?)
- if you're using a laptop for any length of time, attach a mouse if you can, rather than use the touchpad, which, from an ergonomic point of view, isn't designed for prolonged use
- Hold the mouse loosely - do not firmly grip it and click it lightly
- Try to keep your elbow at 90 degrees - a right angle - when using the mouse
- Use your arm to move the mouse, not your wrist
- Use the settings on your computer to adjust the speed of your mouse cursor, the size of the cursor and even the time between double clicks, so that your mouse is moving at the right speed for you and you can see the cursor clearly
- Make use of keyboard shortcuts where possible, to cut down on mouse use
Sitting
- Support your back - use an adjustable chair and maximise the contact between your back and the back of the chair (that is, sit up straight, don't slouch!)
- Sit with your back straight
- Bend your knees at a 90-degree (right) angle
- Leave a small gap between your legs and the edge of your seat
- Keep both fleet flat on the floor, or use a footrest
- Adjust your chair height so that:
- you can use the keyboard with your wrists and forearms straight, not bending. This can help prevent repetitive strain injuries.
- the top of the monitor is at eye level
- Don't cross your legs - this can contribute to posture problems
- Take frequent breaks where you get out of your chair and move around
- Don't sit for more than 30 minutes at a time
Phone use
- Don't hunch over your phone, this can lead to something called "text neck" which can lead to neck and back pain
- Don't cradler your phone between your head and your neck
- Use a blue light filter
- Whenever possible, use your fingers to type instead of your thumbs (hold your phone in one hand and type with the other)
Image source: Computer Workstation Ergonomics: Self-Assessment Checklist National Institutes of Health, Office of Research Services, Division of Occupational Health and Safety - image is assumed to be in public domain as per NIH Copyright policy
