So, I don't really buy the whole "resetting the nervous system" analogy. But I can see why this would work. What the exercise is doing is enforcing good postur

So, I don't really buy the whole "resetting the nervous system" analogy. But I can see why this would work. What the exercise is doing is enforcing good posture while simulating a variety of tasks in your forward workspace. The good posture position that he describes (heal, back and head on the wall with chin tuck) is a standard description of good posture. The person in the video likes to talk about specific nerves - I think its silly to think that way. What's going on is that your reminding your body/brain about what it feels like to 'do work' in front of you while maintaining good posture. Like most physiotherapy (or really any physical skill), you begin with a conscious effort, preferably while providing immediate feedback about the quality of your performance (in this case, it would probably be how well you can maintain your chin tuck and head contact). The goal is that as you drill this more and more, the motor patterns involved become ingrained and eventually active subconsciously. A progression might be that when you begin, that you have to go up against the wall to reset your posture. Then as you go on, you can start resetting your posture at your seat when you notice it. Then the frequency of you having to do it will drop off, and eventually, you'll be able to consistently have good posture with minimal conscious effort.