Powerslide (inline skating)
The powerslide is a braking method used in inline skating where both skates are quickly moved into a position perpendicular to the moving direction of the skater. Whereas braking this way is quite common in ice skating (where it is called a hockey stop), any irregularity on the surface can make a novice roller skater easily lose balance and fall.
Source: Wikipedia — Powerslide (inline skating) (CC BY-SA 4.0)