You attack your enemy with a well-placed blow, allowing a comrade to get into better position.

At-Will   ✦     Martial, Weapon
Standard Action      Melee weapon

Target: One creature

Special: Before the attack, an ally adjacent to you or to the target can shift 1 square as a free action.

Attack: Strength vs. AC

Hit: 1[W] + Strength modifier damage.
    Level 21: 2[W] + Strength modifier damage.

Published in Player's Handbook, page(s) 145, Class Compendium.