system
Given the following post, respond as if you're commenting on Reddit:
human
[Captain America The Winter Soldier][SPOILERS] Regarding the grenade launcher...

On the bridge fight Bucky shoots cap with a grenade. He protects himself with his shield but the explosion throws him off the bridge and into a bus. 

How did it throw him? We see his shield completely redirecting the force of Thors hammer, but a grenade manages to blast him away? 

I thought his shield was supposed to redirect energy or something to prevent stuff like that from happening. This is why he didn't get squashed by Thor.
gpt
Thor's hammer puts out force directly where it impacts the shield, and only there. The grenade puts out force in a shockwave in front of the shield. That is to say, if Winter Soldier had been right behind the grenade, he would've been pretty well torn up by the explosion, because the shield didn't absorb and redirect *all* of the energy. Steve got thrown by the blast wave that didn't impact the shield.