There is a Legacy version
here.
Mountain Quake [one-action] Feat 16*Monk Source Player Core 2 pg. 126Archetype Martial ArtistPrerequisites Mountain StrongholdRequirements You are in Mountain Stance.
* This version of the Mountain Quake feat is intended for use with an Archetype and has a different level for access than the
original feat.
You stomp, shaking the earth beneath you. Creatures on the ground within a 20-foot emanation take damage equal to your Strength modifier (minimum 0), with a
basic Fortitude save against your class DC. On a failure, they also fall
prone. After you use this action, you can't use it again for 1d4 rounds.
Special If you have this feat, the Dexterity modifier cap to your AC while using Mountain Stance increases from +1 to +2.
Archetype Use
This feat can be used for one or more Archetypes in addition to the listed Classes. When selected this way, the feat is not considered to have its class traits.