deff on the back. hip quivers are used by target archers- running around with a quiver on you hip doesnt work. It bounces around, and gets caught on bushes and trees(not to mention bad guys). A quiver on your back is protected. when running through the woods it is behind your head so it doesnt snag on trees. It cant bounce around nearly as much. Plus.... If i had a sword, and i was fighting someone with a bow(ch style, face to face

) and he had a hip quiver, the first thing i would do would be to swing my sword into his arrows, and bust em all up. now he's thoroughly screwed. However, if its on his back, I have to somehow get behind him to break/steal/dump his arrows. Plus,(and you're going to have to take my word on this one) you can pull arrows out of a back quiver MUCH faster than a hip quiver.
I shoot both competitive target archery(with a High-tech compound bow), traditional target archery(stick and a string), and hunt(ive used both-prefer the traditional longbow. hehe just so you know I'm not full of crap.