You attack your foe with a ferocious blow, then pivot and pull your weapon back to your body, unbalancing the enemy.

Encounter   ✦     Martial, Weapon
Standard Action      Melee weapon

Target: One creature

Attack: Strength vs. AC

Hit: 3[W] + Strength modifier damage, and the target takes a -2 penalty to all defenses until the end of your next turn.

  Weapon: If you're wielding a flail, the target takes a penalty to all defenses equal to your Dexterity modifier.

Published in Player's Handbook, page(s) 81, Class Compendium.