Look at the speed they are running at. And the entire body weight concentrated only on 1 leg.

But still, shockingly, I mean, shockingly to me means unexpected, I would say Riise's shot that broke Smith's leg.

That's shocking because the shot was so hard, it broke his leg.

ah, but it was the force of the ball that made him lost balance and fell awkwardly.

So technically, Riise broke his leg. >.<