Root is a soft crowd control. A rooted unit cannot walk but can use jumps, dashes, and teleports(via Smite Wiki). This includes Artemis' 'Transgressor's Fate', Medusa's 'Lacerate', Khepri's 'Solar Flare', and about 10 other moves.
1) Select Ravana as your god.
2) Get trapped in a root.
3) Use 'Overhead Kick'(LB on Savage controls)
4) You should jump out of the root and the achievement should pop.