As unromantic as it might sound, human beings aren’t very different to computers.
Like computers we have finite memory, we have limited processing power, and we have “software” (in our case a nervous system) which manages these resources to help us to deal with the various things which life throws our way.
Another thing we have in common with computers is that this process isn’t perfect. Because of the sheer number of things we have to do at any given moment; managing deadlines, remembering friends’ birthdays, not tripping over in front of the person we like, we have to automate some tasks, so that our conscious minds can focus on the essential things like getting work done or searching for cat videos on YouTube.
If our conscious minds become overwhelmed, more and more pressure is placed on our nervous system until it’s processing power starts to run low. As it does, the quality of the tasks it’s been left responsible for starts to suffer. Things like posture, short term memory, even breathing begin to deteriorate until we end up looking like our friend in the photo above.
The wrong tool for the job
(Kind of) thankfully, before anything as dramatic as a system shutdown happens, the decreased functioning will often lead to pain, letting us know that something’s wrong. What often happens at that point is that our conscious mind steps in and tries to fix the problem.
In the case of posture for instance, what most of us do is try to take control of the body consciously, and hold it in a position that is more “structurally correct”. We straighten our spine, pull our shoulders back, lift up our heads, and things, appear at least, to be better. For two reasons though, this rarely actually solves the problem.
One, this process almost always adds tension rather than reducing it. Or at best, it replaces tension in one place with tension in another. There are just too many parts for the conscious mind to organise effectively, so it uses tension to try to hold the body in a “better” position. 
Secondly, even if it did produce a genuine improvement, the conscious mind just isn’t set up to carry out this kind of task over time, and will soon have to abandon it to refocus on other, more important tasks. This sends the job back to our already overstimulated nervous system and things get even worse.
As much as possible, rather that trying to reposition the body consciously, we need to trust the nervous system to figure things out for itself. This is much easier said than done though. Especially when we’re in pain and our stressed out nervous systems have gotten us into this mess to begin with.
Rather than using our conscious mind to force ourselves to “sit up straight”, we need to do the opposite. By learning to manage stress in a less reactive way, and by bringing more awareness to our bodies, we can begin to free the nervous system from the pressure that it’s under and regain the use of its resources.
In other words, instead of applying new tension in an attempt to fix problems caused by existing tension, the key is to take a moment to come off the mindset that has caused the tension in the first place, and then practise maintaining this healthier mindset as we go about our lives.
Human beings aren’t very different to computers. But we are different. We can access and even rewrite our software if it’s not working in the way that we want it to. This isn’t an easy process, but it’s one that a computer can’t hope to match. At least until they become self aware and turn us all into batteries or something…
 In fact, many of the muscles that control posture aren’t even under conscious control, they operate naturally when we get out of the way, and allow the body to function as intended. ↩︎