You expend some of your rage to throw one opponent at another.
Prerequisites
Strength 13, Constitution 13, Rage special ability, Power Attack, Improved Bull Rush, base attack bonus +6.
Benefit
When you attempt a bull rush combat maneuver while raging, you can spend 1 round of your active rage as a swift action to add your Constitution bonus on your combat maneuver check.
Further, if you bull rush an opponent into a square occupied by another creature occupies or a solid object, the opponent and the creature or object take bludgeoning damage equal to your Strength modifier + your Constitution modifier + the number of every Frenzy Feats you possess.