hit the ground running
This exercise is pretty straight forward: Open your mouth. As far as you can. And since we want to open it even further – to widen it a little – we now use our hand: Just clasp your chin and then pull downwards. And so you don‘t get a crick in your neck, we take the other hand and hold our head – you don‘t have to overstretch anything – just so that you can easily spread out your jaw with both hands. And now increase the pressure for two, maybe two and a half minutes, and keep holding it just as intensely as it is comfortable for you to suffer.