E.G if I where to kick I would like an effect to go on the leg that is kicking to show how much power is going into the kick.
You could make a script that plays the animation, and waits for as much time as you want to show particles when you want.
Your only option would be to wait or split the AnimationTrack by it's length (AnimationTrack.Length). You'd still need to wait, though.
[ Length ] https://developer.roblox.com/en-us/api-reference/property/AnimationTrack/Length
[ AnimationTracks ] https://developer.roblox.com/en-us/api-reference/property/AnimationTrack/
You might be able to do something hacky by checking it's CFrame/joints but that wouldn't be really worth the effort. Just use a wait, and time it right (shouldn't be too hard).
This type of thing is pretty simple, you could clone a particle emitter to the character's leg, then wait, and have it destroyed.
local cloned = ParticleEmitter:Clone() local playanim = humanoid:LoadAnimation(kickanim) playanim:Play() cloned.Parent = char:FindFirstChild("RightLowerLeg") wait(0.4) cloned:Destroy()