Source: Complete Warrior
You are adept at breaking up formations of soldiers when you rush into battle.
Prerequisite: Improved Bull Rush, Power Attack, base attack bonus +6.
Benefit: The Shock Trooper feat enables the use of three tactical maneuvers.
Directed Bull Rush: To use this maneuver, you must make a successful bull rush attempt as part of a charge. For every square you push your foe hack, you may also push that foe one square to the left or right.
Domino Rush: To use this maneuver, you must make a successful bull rush attempt that forces a foe into the same square as another foe. You may make a free trip attempt against both foes at the same rime, and neither foe gets a chance to trip you if your attempt fails.
Heedless Charge: To use this maneuver, you must charge and make the attack at the end of the charge using your Power Attack feat. The penalty you take on your attack roll must be -5 or worse. In addition to normal charge modifiers (which give you a -2 penalty to AC and a +2 bonus on the attack roll), you can assign any portion of the attack roll penalty from Power Attack to your Armor Class instead, up to a maximum equal to your base attack bonus.
Special: A fighter may select Shock Trooper as one of his fighter bonus feats.