From Pathfinder #151: The Show Must Go On, which isn't enabled.

Levering Strike

FEAT 8

Activity 2 actions

Requirements You are wielding your staff.

Make a Strike with your staff. As long as you don't critically fail, the target becomes Off-Guard and takes a -2 circumstance penalty to its DC against Shove, Trip, and Tumble Through attempts until the start of your next turn.

Pathfinder #151: The Show Must Go OnOGL