What is Harau?
“Harau” (Sweeping technique) is a foot sweep in which the opponent’s foot is swept out from under him. The Harau maneuver is used in Waza such as the De-ashi-barai (-harai) (Forward foot sweep), Harai-tsurikomi-ashi (Lift-pull foot sweep), Harai-goshi (Hip sweep), and the Okuri-ashi-barai (-harai) (Foot sweep), etc. This maneuver targets the leg which supports the opponent’s weight while he is attempting to recover his balance after being destabilized, and easily topples him.
This maneuver represents the fundamental principle of Judo, in that the opponent is toppled by adding only a small force to the opponent’s momentum. The success of this Waza depends on the execution timing, the sweep angle, which part of the opponent’s leg to strike, which part of one’s own foot to use in the sweep, etc., and therefore requires repeated practice.