Say you had 2 bushings sitting on the floor, one was compressed and the other wasn't. Now say you apply a sudden forceful impact to both via a sledge hammer. The compressed bushing would be more likely to rupture because it is already under pressure and is not capable of absorbing the shock as it was originally designed to do. You have to remember that the gel is in there to dampen shock. Like any fluid it can't be compressed. Hey look at that, college Physics actually came in handy :-)