As an action, make a melee weapon attack with a weapon that deals bludgeoning damage to cause a tremor to ripple out from the creature. Each creature on the ground other than you within 1 meter of the creature must make a Reflex saving throw.
On a failure, a creature is knocked prone.
Enhance
You can augment this maneuver with the following options, expending stamina dice for each option.
You can add the stamina die as bludgeoning damage if the creature fails the saving throw for each additional stamina die expended.
You can expend 1 additional stamina dice to increase the area to within 2 meters of the creature.