When you were a wee thing in the assembly hall at school, it was so easy to sit with your arms and legs crossed for - what seemed like - hours upon end without having cramp, and still being able to walk afterwards.
As we get older, and our concentration spans lengthen (in theory anyway), we find ourselves sitting for longer periods of time. We don't feel the need to jump up and down the aisles in the supermarket, or challenge ourselves to stay standing for the whole train journey. Instead, we tend to assume a sitting posture in the morning which we alter only a few times in our day.
Think about it: most of us will travel in to work by vehicle (sitting down), then work at our desk (sitting down), eat (sitting down), go home and watch the television (sitting down).
Are you seeing a pattern here?
The spine loves movement, and your joints will thank you for changes in positioning by not stiffening up. But if you have to sit for long periods of time, make sure you follow these tips for a healthier, more comfortable position:
1 Keep your feet flat on the floor
If you're of a smaller stature, use a footrest and make sure your feet are well supported on a flat surface. Play about with seat height (actually, play about with all the little levers on your seat. You might surprise yourself by how different you feel after even a small change in position).
2 Make sure your thighs are supported
For tall people, whose feet reach the floor no problem but their knees are knocking on the underside of the desk, this is essential. Make sure your seat is deep enough from front to back to support the whole length of your thighs. The bigger your base of support (i.e. the area where your bodyweight is resting on a surface), the better.
3 Keep your back upright and supported
The reason we don't say "keep your back straight" is because that's misleading: your spine has a natural "S" shaped curve to it, and it's this curve that you want to maintain, rather than a striving for a "flat" back.
This will prevent your neck from being strained. Bit of a tricky one with a laptop, but if you can support the screen (even on a very un-fancy box) and use a keyboard at the right height (see number 5) you'll feel much better for it.
5 Make sure your forearms are supported
See number 2! Again, making sure more of the weight of your upper body is supported on the desk means that your shoulders and neck won't have to take the strain of holding your arms up (we're not all The Incredible Hulk with ginormous arms but every little helps!)
6 Move frequently
A-ha! The key here is movement. Even a small change in position can remove stresses from certain areas. The idea is to move every 20 minutes, even if it's to stand up and walk to the window and back, or just to do a wee dance. You might look silly but you'll be walking tall at home time.