In rugby, when the ball is near the goal line, the team in possession often forms a scrum and simply tries to push the ball over the line by shoving the other team backwards, just like the tush push. As you may recall, until fairly recently, it was a penalty for another offensive player to "aid the runner" by pushing him forward. No idea why or when that ancient rule was changed. And no, a simple pitch play isn't really a rugby play (perhaps more of a Rugby League play), although it certainly happens in Rugby Union, too.