>>11801385Here's what I know about it
Your front muscles are too short and your back muscles are too long, your nervous system also protects you from injury by preventing full extension of muscles (not as important but this is why PNF stretching extends range). These combined are why you can't get your back to look straight like in childhood. If you have scheurmann's your vertebrae are tapered and you can't completely fix your back without surgical fusion.
https://en.wikipedia.org/wiki/Scheuermann%27s_diseaseIf you spend 30+ minutes with a muscle in an extended position, you'll grow new sarcomeres and lengthen the muscle. This is how the length of your muscles got unbalanced in the first place, long periods of slouching. I don't know how long it takes for a muscle to shorten by staying contracted.
So as far as I know all you'd have to do is figure out how to spend long periods of time with your back in an erect position, and prevent slouching. I made pretty good progress by laying on a board and using my computer in a supine position, but I took it down because the setup was unruly.
