that must have been the "chum sun" motion. it is the last movement in the third form (before the final punchs)
every other movment from every other form has use and purpose in fighting, but thats just a nice way to stetch out your back. honest
I am only a "chum kui" level student so I don't practice bui jee, but I'm sure if its in one of the three hand sets, its meant to hurt people in some way.
"Cyanide is a dangerous chemical. That's why it is a crime to possess it without a peaceful purpose," said U.S. Attorney Fitzgerald.