Ryan Young explains how to back roll. The back roll is like a chest roll, except the disc rolls down the backside of your arm and then across your back. Many people finish by letting the disc roll to your elbow and turning fast to shoot it back up. This is the style Ryan calls “the buckle“.
Ryan explains how this is done in masterful detail so give it a watch. If you need more, here’s another video and explanation. If you have any questions, leave a comment.