Ollie
From Tardis Wiki, the free Doctor Who reference
The ollie was a skateboarding trick where the participant leapt into the air without using their hands. To do so, according to Alan Jackson, one had to bend their knees. When Clyde Langer failed to do so, and only managed to fall to the ground, Alan, having been named King of the Concrete in his youth, demonstrated the proper way of doing it. (TV: Whatever Happened to Sarah Jane?)