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Ergonomy at the Computer
Nowadays, many people work long hours sitting at a computer desk, watching a screen. This is especially true in the world of CG animation because digital artists must absolutely use computer software as a tool to create works of art. But most of us have habits formed by many other factors than an ideal ergonomy for the body.
Here are the good and bad sitting habits when working at a computer desk. We hope to demystify some myths and misconceptions and offer good alternatives. Of course, you must always refer to your doctor for medical advice specifically tailored to your own situation. If you're working long hours at a computer desk, we aim to help you improve your sitting posture today!
A Quick Note on Human Anatomy
Did you know that the human back is not a perfectly straight line when seen from the side? And unlike what many chair manufacturers and designers seem to think, the human spine has a smooth but subtle 'S' shape. This allows it to distribute the weight more efficiently.
It needs to stay this way to preserve the soft padding in-between all your vertebrae. After all, it holds all the weight of your shoulders, arms and head. Of course, the spine should be straight and symmetrical when viewed from the front, to distribute evenly the weight of both halves of the body.
Sitting Habits to Avoid
Here are 4 sitting habits that are bad for you and that you should kick out for good, this time!
Crossing your legs
Crossing your legs, over the other or under you may not seem like a big deal, but it unbalances the whole center of gravity. This forces your body to adapt your back, creating an asymmetric 'C' curve in your spine, as viewed from the front! It also usually also comes with a slouched lower back and a forward-leaning head. In short, it's very bad.
When you do this frequently over long periods of time, you'll start to notice that you can't cross your legs equally on both sides. This is because you're actually pulling on one side of your whole body more than the other, and this creates a 'permanent' asymmetry in the tension of the muscles of that side. It may affect your posture in the long run.
Oftentimes, you'll also find that you're leaning on one side more often than the other when sitting. This also usually corresponds to the same side as the leg-crossing side, as it re-creates the same angle on the back.
Slanting on one side
Sitting on either side, either in a 'J' or '/' position is not good for your back and your neck, even if it may seem so at first. We usually tilt the head and upper back on the opposite side than the arm controlling the mouse, resting most of the weight on the opposite armrest.
Other people fold a leg under their body, which in turn creates the tilt resulting in the same problems in the end. It unbalances the symmetry of the body, requiring more tension on one side than the other and pushing on the discs in between the bones of the back and the neck
Another similarily bad habit is to lean onto the arm-rest on the side of the mouse. This is not only bad for the back and neck, but also for the arm, shoulder and wrist on that side.
Slouching the Back (The 'C')
Whether you're sitting on a chair, long couch or bean bag, sitting with your back slouched, is always a bad idea. The lower back needs support to lift the hips higher up and create the nice natural 'S' curve in the spine.
Otherwise, this creates pressure on the spine and neck, as it deforms into a 'C', instead of its habitual shape. A slouched lower back, often also leads to a head leaned forward or downward.
Leaning forward is common in order to better see what's on a computer screen, especially among people with myopia. Sometimes it's because the screen is too far, sometimes the glass prescription may need an update. In any case, a screen should be 16 to 18 inches away from the eyes of the user, when his back straight, not leaning forward.
The problem with leaning forward is that it puts the vertebrae of the neck in a very precarious situation. Having the chin on its forwardmost point means the bones are pushing on each other using a very small area of their edges. If there is any sudden movement, there is a risk that it can cause a strained a muscle or tendon, or damage to the padding or the bone itself. This type of neck injury is not always noticeable on the same day as they happen, making it difficult to correlate to a specific event.
Sitting Properly on a Chair
Legs and Back Sitting Method
Here is a few simple steps to allow you to position your back properly in a chair, keeping the right S shape it needs. You can use this method right from the start of the day or to 'reset' your sitting position from time to time. Even if it may look odd to your colleagues, at least you won't be the one with back pain later.
- Sit down on the chair with both feet touching the ground, spaced by one feet.
- Push yourself back, to the furthest possible point in the chair
- Lower your upper body from your shoulder to your knees
- Slowly raise your upper body vertically again, without sliding on the chair
- Rest your back on the back of the chair and keep your arms hanging along your body
- Stretch your body upwards, as if it were 'pulled from the head up', to reset the spacing in
- Relax all your muscles and rest naturally your back on the chair
The ideal Pose
This aims to rotate your lower spine around your sitting position, at the end of the seat, creating the bottom part of the 'S' shape. When you release the muscles in your back, the top side of your spine will balance on this, creating the top part of the 'S'. In the sitting position described above, you shouldn't even want to cross your legs because it would be uncomfortable. If you can cross them without feeling strain, then your back is probably not positionned correctly.
The ideal pose should be a relaxing point of balance that is comfortable to work in for an hour or so without strain. If at any time you feel strain, muscle fatigue, incomfort or pain when working at a computer desk, you must absolutely change position or stop working entierly for 5-10 minutes. You can then use the sitting technique above when you come back to your desk to 'reset' your sitting position.
Arms & Wrists
- Join your hands on your lap and put your elbows on the arm rests.
- Make sure that your shoulders are neither pulled upwards, nor pulled downwards from your natural resting position.
- Put your hands on the keyboard, straight in front of you
- Your elbows should form 90 degrees angle between your forearms and your upper arms.
- Your wrists must be in line with your forearms, without break.
If not, you may want to have a lower desk or a higher chair. You could also have a separate keyboard tray, under the desk to help keep the posture right.
The most important is that your wrists should be aligned with your forearms without break. When typing on your computeror clicking on the mouse, this is what is most problematic. This meas that the wrist resting on the desk or wrist-rest should about at be at the same height at your elbow resting on the armrest.
You head should look straight forward into the top third of your computer screen. Depending on the size of your screen, this usually means the top of your head almost aligns with the top of the screen, for a reasonable 24 inch screen.
- If you have to look upwards to see your screen, raise your chair and keyboard area.
- If you have to look downwards, put something under your screens to raise them, like a stand or a stack of paper.
The screen should be at about arms length away from your eyes. Never tilt your neck forward to look at your screen. This is very very dangerous for your neck, as it is holding on the edges on the vertebra. Any slip and your body will trigger an inflamatory response to protect the tendons, which will result in neck pain.
If you have more than a screen, make sure your primary one is the biggest one. Always place this one straighter in front of you than than the other one. This ensures that you don't have to either stare at the gap in-between screens or constantly tilt your head on the sides. Tip: your brain will choose function over comfort, if left to involuntary reflex. Might as well choose ahead of time and make it more comfortable by force. Nevermind your desire for symmetry.
Ideally you should have 3 screen: so you'd have your main one in front of you, and an extensions on both sides. But this is really not necessary and is often complicated in most room and desk sizes. Budgetwise, 3 screens also often require a much bigger budget, as it will probably require:
Choosing a Good Work Seat
Office and gaming chairs have a lot in common, they're made for long hours of computer work. It is important to find a good chair, that will be comfortable for the person using it, so it's best to try before you buy, in this case.
Here are the main goals of a chair for good ergonomy:
- Support the lower back(can be done with a separate cushion)
- Support for the neck
- Some cushioning for shocks absorbance and movement
- Allow the back to recreate the 'S' shape of the spine
- Allow for back angle adjustments
- You need to be able to touch the ground at all times (height adjustment)
Find a chair with the following attributes:
- 360 Angle of Rotation (standard)
- Adjustable seat height (important)
- Adjustable back angle (important)
Optionally, it should also have the following too:
- Adjustable seat angle (rarer, but very practical)
- Armrests are important, and ideally with:
- Height adjustments
- Soft padding
- Removable if needed
- Wheels (often standard)
Wheels often come standard at no extra cost but beware of the damage they do on wood floors. It's like none other, even if you try to be careful unless you take measures to protect from that. You can use a rug or a plastic floor mat, sold separately, to go under the wheels.
Stretching and Taking Breaks is Crucial!
The body was made to move! So it's no wonder that sitting down 40 hours a week in front of a computer is very hard on the body. In fact, it is downright bad for you, almost as much as smoking. You can sometimes feel it in your back, in your neck, in your shoulders and on the size of your belly.
After all, your body is made of 90% fluids and it was made to be constantly in movement. Different systems in the body, like veins, use the movement of muscles to circulate fluids and make everything work. The body is an incredible machine, as any character modeler or rigging artist can attest to.
In fact, it's the equivalent of a billion dollar machine, so you should to take very good care of it. That's why it is crucial to take steps to combat the sedendarity tha comes with computer work. Here's a few tricks:
- Change position often on your chair (every 10 minutes or less)
- Stretch often, and any where that feels slow or 'numb' from lack of movement.
- Shake your legs when listening to music (while making sure not to disturb your colleagues!)
- Take mandatory breaks of at least 5 minutes every hour, or 15 minutes every 2 hours.
- Walk around the block at each opportunity or break you have, even during winter.
- Take your full lunch break time and relax, go take a walk or go to a gym.
Alternatives to Sitting on Chairs
We cannot recommend these methods at this point, but here are a few alternatives computer workers have been seen to try, to avoid the sitting position. It's been seen to work for some people more than others, and it is still unproven to be better, but some have found ingenious ways to avoid sitting. Take note that it usually takes some accommodations and approval from the employer to be able to implement these options.
It takes a desk high enough, but this forces your lower back muscles to avoid the slouched back. While this is good, it also means you will be constantly flexing your lower-back muscles to push it forward.
Some people go as far as to work while standing up to avoid static positions altogether. A more extreme of the standing desk is those who work on a treadmill, a walking exercise machine.
Some people prefer hard chairs, but remember that the spine is not as straight as the back of a wood plank.
This is a very bad idea for long hours of work, it is simply too uncomfortable and ever-shifting. It's only seen in movies or 'hip' new office spaces, or for quick team meetings and projection rooms.
We recommend this article for a better posture while sitting, from a master fabric maker.
In the past century, many Americans have lost the ability to sit in a way that doesn't strain their backs. Specialists say we could take a lesson from excellent sitters from other cultures.
And this site has a great inforgraphics of DOs and DON'Ts
Go to the 'computer hardware' table of contents:
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