Humans were never designed to spend 8-10 hours a day seated in front of a computer! Sustained desk postures, particularly under work stress, place individuals at great risk of muscular overload and pain. In addition to taking hourly breaks from your seated position, efficient desk posture greatly reduces the risk of overload pain. For individuals who already have pain, improving their desk posture gives them the opportunity to address what is often a key driver of their pain. An efficient posture ensures that gravity is your friend, not your foe.
Basic Sitting Posture
Two basic things to start
- Place your backside right at the back of the seat pan so that your low back stretches over the lumbar support. If you have shorter thighs, then you will need a seat pan that isn’t too deep. There should be at least 1-2 cm between the front of the seat pan and the back of your knee.
- Lean your trunk back so that it is slightly behind the “plumb line” (vertical line up from your hip). If you are in a stable position, it should be possible to relax your neck and shoulder muscles without slumping forward.
Three things to make sure you stay in a good position
- Pull your chair forward so that your tummy touches the desk – if arm rests prevent this, then take them off.
- Adjust your computer screen to suit your eyes (vision drives our posture). Raise the screen so that the top third is at eye height.Place the computer screen at your preferred “focal” distance whilst you are sitting in a safe position.
- Gently press the soles of your feet down on an angled footrest under the desk.
Finally check the seat height
Adjust the height of your seat so that your elbows can hang by your sides, leaving your forearms horizontal. Many people have their seats too low, which tends to overload their yoke and shoulder muscles.
Problem Desk Postures
There are two common problem postures at a computer desk:
- The “Slumper” - whose head slumps further and further forward as the day goes on.
Vulnerable to low back pain, yoke tightness, neck pain +/- headaches.
- The “Bumslider” who lounges back and slides their bum forward across the seat pan as they get tired. Vulnerable to hip crest, mid-thoracic and neck pain.
The ideal computer desk posture is halfway in between the slumper and bumslider postures, with an upright posture that allows the chair to take most of the weight.
Tips for Slumpers
- Ensure that trunk is leant slightly backwards, just behind the plumb line
- Pull your chair forward so that tummy touches the edge of the desk
- Have computer screen at eye level and relatively close to your eyes, so that your first instinct is to pull your head even further back behind the plumb line.
Tips for Bumsliders
- Use a piece of rubber non-slip matting on your seat to make it harder to slide forward.
- Ensure that backside starts at rear of seat pan
- Get rid of armrests, as they may encourage you to slide down the seat pan
- Raise the computer screen so that the top third is at eye level when you are sitting up
Only about one-third of office chairs get a pass mark for ergonomics and an investment in a new chair may be required. A good chair will be adjustable for seat height and back support. The back rest should at least reach the bottom of your shoulder blades and not extend above your shoulders. There should be a gap for your backside to fit into and a decent amount of lumbar support. Arm rests are often best removed, especially if you have a longer trunk / shorter upper arms.
The desk should allow you to sit square-on and get your thighs close up underneath the keyboard. If you are particularly tall or short, then an ability to raise or lower the desk from the standard 700mm can be helpful. Standing desks are good for breaking up your posture through the day but it is just as important to stand well. All the same desk and screen relationships should be in place when you are standing.
Laptop computers are not designed to work at for lengthy periods. Consider attaching a large screen and full size keyboard when at your usual desk.
Large lenses are safer. Small lenses (half glasses) and bifocals / graduated lenses encourage people to “look down their noses”. This in turn juts the head out in front and favours a slumping posture.
Use your diaphragm so that your tummy goes in and out with each breath. This maximises concentration, endurance and performance. It also helps us to keep control of our stress response.
Dr. Chris Homan
MBBS FRACGP FACRRM DRANZCOG PGDipMSM(Otago)