When attempting to use straight/uppercut/kick on a structure that is simultaneously being hit by a disc, the structure does not move.
I admit there are ways to fight against this, but I am frustrated that this is such and easy thing for the opponent to do.
On the Ring it can't last for long as the opponent loses space with every disc, but on Pit they can have their back to the wall without repercussion.
If I recall correctly, in a future update to the damage system the player will take damage from being forced into the environment/structure. This may help.