add force to rotation (2d game)

Here I am again with another problem…
when my character falls to the ground, I wish there was a push to take him back to his feet. The effect is like the one used in this game: Discover and Play Free Online Games on Kongregate!
but i but I can’t find a way to do it.
there is some kind soul who can help me?

I’m interested in a possible solution to this :smile: