Demo at K of C in Brooklyn, NY 1969-70. I was 5 feet 11 inches at the time, so I know the height was over 6 feet for the board break, it took me three attempts to make it.
Event: 3RD MOO DUK KWAN® USA VIRTUAL COMPETITION REGISTRATION
Competitor: Maximilian Leizenovitz
Division: Prerecorded (Hyung)
Hyung: Ki Chi Hyung Sam Bu
Event: 4TH MOO DUK KWAN® USA VIRTUAL COMPETITION REGISTRATION
Competitor: Leo Blair
Division: Warrior Tots (Hyung)
Hyung: Warrior Tot Hyung or Techniques