Check if object is applying force to another object

Is there a simple way of doing this?

My player character is a Rigidbody. He thus has the ability to push around other Rigidbody objects in the game. I just want a quick way of triggering a "pushing" animation on the character. It seems like the best way would be to see if force is being transmitted specifically from one object (player) to something else, and if yes, play the animation. I don't want to just start playing the animation on collision or trigger, because I don't want the animation to play if the player is simply standing right next to the object without pushing it.