Yeah but,about the effect it causes,did you modifiy it or something?
Since no one answered your question, I will, since I do not care about modding anymore and don't wish to hide anything I know.
It's HitTrees.
You can like:
local Ped = PedGetTargetPed()
if PedIsValid(Ped) and PedIsPlaying(Ped, "/Global/HitTree/Standing/Melee/Generic/Stunned/BodyStun", true) then
ExecuteActionNode(Ped, "/Global/HitTree/Standing/Melee/Unique/SACKED/Front", "Act/Anim/HitTree.act")
So you simply change the BodyStun animation to a SACKED animation.