Collision not working after moving armature/setting different pose I have set up low-poly collision objects for the beard and the body. Both are parented to the armature with automatic weights and in the rest pose the collision is working nicely:

However, after moving my armature into a different pose, it seems to forget about the collision. Specifically, the beard collides as if the collision object did not move at all (still at its position in the rest pose) although it has visibly been moved as well. 
What is happening here?
So I was able to find the answer for my problem: I parented the chest_collision object to the armature with empty weights instead of parenting it to a bone. Moving the armature would move the collision object like I wanted but the collision seems to be calculated based on the object's origin.

Sure enough, going into edit mode reveals it at the location of its origin:

Parenting the chest_collision to one of the neck bones fixed the problem!