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.