The PhaserGames.com site has a new tutorial series on creating an Endless Runner game in Phaser. In part four: "Although we will create the illusion of running, as you probably have guessed by now, we will actually be moving the blocks. The temptation is to just move the group as one in the update function."
"But if we did that we couldn’t take advantage of the built in physics that Phaser has to offer. For the arcade physics collision detection to work the blocks inside the group need to be enabled for physics and they need to have velocity set."