Battle Captain Attack 20Cunning Flurry
You whirl around like a cyclone of steel terror, slashing at foes. With each landed blow, you knock your enemy prone or send it stumbling backward.
Daily Martial, Weapon
Standard Action Close burst 1
Target: Each enemy you can see in the burst
Attack: Strength vs. AC
Hit: 2[W] + Strength modifier damage, and you either push the target 1 square or knock it prone.
Miss: Half damage.
Published in Player's Handbook, page(s) 154, Class Compendium.