Anyways in the "Under Sarthal" quest right after the "Tell Tolfdir about the vision" step, you are attacked by 2 adversaries. After disposing of them, in the very next corridor that opens - before you open the gate, there is a skeleton on the ground. If you run over the top of this skeleton, it will have a chance of causing you negligible damage and it will accelerate you into whatever wall you are looking at. Not a major bug by any means, but something to put on the "todo list". Here is a short clip displaying the behavior.
http://vimeo.com/31985944
