How to check if a player is standing still?

I am currently making a game where you can turn using A,D and S keys with tweenservice, to do this i also have to make the humanoid root part anchored, but one issue with this is if the player is falling they will freeze in the air, is there anyway to check if the player is idle, I have checked the humanoid state types, and i do not see any idle state, so i am in alot of confusion right now.