Your critical hits can push back your foes.
Benefit: Whenever you score a critical hit with a melee attack, you can push your opponent back, in addition to the normal damage dealt by the attack. If your confirmation roll exceeds your opponent’s CMD, you may push your opponent back as if from the bull rush combat maneuver. You do not need to move with the target if successful. This does not provoke an attack of opportunity.
Special: You can only apply the effects of one of the following feats to a given critical hit: Bull Rush Strike, Disarming Strike, Repositioning Strike, Sundering Strike, or Tripping Strike. You may choose to use this feat after you make your confirmation roll.
Advanced Player’s Guide. Copyright 2010, Paizo Publishing, LLC; Author: Jason Bulmahn.