Your bull rush attacks throw enemies off balance.
Prerequisites
Str 13.
Benefit
You receive a +4 bonus on checks made to bull rush a foe. You also receive a +4 bonus to your Combat Maneuver Defense whenever an opponent tries to bull rush you.
If you have a base attack bonus of +4 or higher, whenever you bull rush an opponent, his movement provokes attacks of opportunity from all of your allies (but not you).
Normal
Creatures moved by bull rush do not provoke attacks of opportunity.