You can barrel into your opponent and follow this with an attack.
Benefit: On your turn, you can perform a single bull rush combat maneuver in place of one of your melee attacks. You must choose the melee attack with the highest base attack bonus to make the bull rush.
Pathfinder Roleplaying Game Ultimate Combat. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.