How To Set Up 3D HitBoxes For Animated Character?

Such as detecting when the left or right fist/foot collide with a head.

I tried creating a box mesh in Maya attached to the joint then in unity giving these box meshes a physical collider to act as a trigger, the problem is that the trigger does not move with the mesh.

Now my alternative is to use raycasts to detect collisions but this requires a collider as well...

How do you trigger on an animated object?