Good work on the facial animation, and the fixes to the ankles and blades.
Now about the body animation, although I like where it's going, I'm not sure about the timing.
The way see it now, the animation is a four-step:
1. Shoulders go up, chest widens
2. Head goes forward
3. Shoulders go down
4. Head goes back
It looks a bit disjointed. As if he was coughing in slow motion.
The head going forward should be part of the same motion as the shoulders, and both motions should peak at the same time.
It should be the inhalation that drives all of it.
To sum it up, I'd make it a two step:
1. Shoulders go up, chest widens, and head moves forward
2. The whole thing goes back to starting position.
If you're in the mood for experimenting, you could also try having the head move the opposite way.
That is, reaching the furthest forward at the peak of the exhalation instead of the inhalation.
That way I guess it will look less "beastly" but more natural.