Gravel is one of J.D. and Turk's games created by J.D. where one person puts gravel in another persons shoe. When this is done the person watches the other limping and announces "They have been gravelled!" It idea occurred to J.D. after he got gravel in his shoe after taking a short cut through the quarry. Janitor at first thought J.D. was doing a new "cool walk", to celebrate his promotion, but he was actually just limping in a strange way.