You can force your opponent to yield ground when wielding a martial arts weapon.

<php>echo “<b>Prerequisites:</b>”;</php> Weapon Mastery (Martial Arts)
<php>echo “<b>Benefit:</b>”;</php> When making a full attack action with a martial arts weapon, you may push your foe 5 ft. with each successful attack, moving into the space your foe previously occupied. Creatures more than two sizes larger than you cannot be pushed in this way.