You don't lose the posture, you change your posture.
Bones are in a position muscles pull them, and muscles pull how brain order them to. So to change posture we must change brain patterns and you can do that by education and not by forcing bones to a different position, and not to deal and cope with pain and hope for the best. In video you can see how red light reflex changes posture in time. And it's not because of time.