**Foreword:** I am unsure if this is a bug or not, but I really hope it is _(becasue it's incredibly misleading if it isnt)._ Either way, i believe something should be done about it.
We have all experienced this at some point and know how frustrating it can be:
You get knocked up, but even once you have touched the ground there is a small period where you are still unable to do anything, and you sit there thinking _"I should be able to get away now.. why cant I do anything!?"_
I have tested it with both Malphite and Kalista's ultimate knockups _(at rank 1)_ as they are the same duration, but will use Malphite as the example here as more people are familiar with him, and it is easier to show _(less particle effect clutter, and fewer champions involved)._
Malphite's knockup lasts 1.5 seconds. In theory this means that once he strikes your champion, your champion will be airborne for 1.5 seconds and be unable to move or cast spells until the instant you land on the floor. However in the video you can clearly see that Ezreal is still disabled AFTER the knockup has ended.
I have repeated this several times, and measured the exact time frame by frame. The actual time spent in the air is equal to 1 second _(+/- 1 frame, recorded at 28fps)_ and the time spent disabled on the floor afterwards is equal to 0.5 seconds _(+/- 1 frame recorded at 28fps)_. From this we can conclude that the total time you are disabled is 1.5 seconds, which is the correct amount of time that you should be disabled for.
**However**, with Riot's stand on in-game-clarity in mind. We can see that there is a problem.
The length of all other CC in the game is clear, when you are hit by Morgana's Q, there is a clear purple barrier around your champion until the moment that you are released. When you are stunned, you know you will be stunned until the moment the little purple swirl stops spinning. When you are slowed you know you will no longer be slowed once the yellow/blue trails are no longer following you.
Therefore, we assume that knockups are the same, you can clearly see when you are airborne and you can clearly see when you are on the ground again.
So it is with **this** mind-set that we go into battle, and so we get frustrated when our champion is clearly on the ground, but still cannot move, and why you get mad when you land on the ground, and THEN Yasuo ults you, and you throw your keyboard down and say _"WTF I WASN'T EVEN IN THE AIR ANYMORE!!"_
It is at this point that i will make a comparison to Alistar's knockup. As stated in the breakdown of Alistar's Q ability: _"Alistar slams the ground beneath him, **knocking up** nearby enemies for 1 second, **stunning them upon landing** and dealing magic damage."_
This ability is different to the other knockups in the respect that the 'knockup' part of the disable ends _exactly_ when you touch back down on the ground. _(Malphite's ability is stated purely as a knockup, and so shouldn't continually disable anyone after they hit the ground.)_
The total time spent disabled in Alistar's Q is no different than with Malphite's R. The difference being, that the 0.5 seconds spent on the ground, counts as a **stun** for Alistar, but counts as a **knockup** for Malphite. I have tested knocking up Irelia _(while outnumbered and with merc treads)_ as Malphite and her tenacity did NOT reduce the time spent disabled on the ground. Proving that it is indeed still classed as a knockup.
When players are knocked up by Alistar, they expect to still be disabled after they hit the ground. While players knocked up by Malphite, expect to instantly be able to move again once landing. **This is an important distinction in regards to clarity!**
Players like to know whats happening to them and why, and people do not enjoy not knowing why Yasuo can still ult them while they have 2 feet firmly planted on the ground, as well as having no clue why they cant flash away after a Malphite ult.
So I propose that **either:**
1. All knockups that this affects, are broken up into distinct 'knockup' and 'stun' effects like Alistar's Q.
2. All knockups that this affects, have the animation of being airborne, extended to match the duration of the disable.
As it is clearly misleading and frustrating, when there is no visual cue that your champion is disabled _(except for a tiny white bar below your HP.. which lets be honest, is near impossible to see when a Malphite just engaged on your whole team in a teamfight.)_ When you get hit by a knockup ability and your champion is up in the air, you expect to be disabled, when they are on the ground again, you expect to be free to move and cast.
There is no good reason why this should even be the case anyway.
The only reason I can think of as to why the game is currently working in this way, is that longer knockups might look odd, seeing your champion naturally suspended in the air for long period of time. The solution to this problem is to either: Have long knockups raise your champion higher in the air _(like a Janna Q)_ or to just break the disable into a 'knockup' and a 'stun' as aforementioned. The latter will be a slight nerf to Yasuo, as he wont be able to ult people once they land anymore. _(but to be honest he shouldn't be able to ult people on the ground anyway.)_
And i would love to hear Riot's view on this as well.