Way to do this?

[RobBaer]

Unlikely. This is something that is best done in a downstream program like Blender, and should be fairly easy to accomplish with tools like "proportional editing".

[brkurt]

One way to do this is to create a separate model with different weight painting, and then apply a force (with an empty object) in Blender.

Weight panting can be used to make an object jiggle like this.

https://www.youtube.com/watch?v=ZfAJeUYAv3M

The trick here is do what a stunt person would do; it only has to appear as a striking blow.

You can then decide how many frames you want the force object to operate in; usually 24 frames for a full second of strike.