That was from the last day of his concert, his pinky fingers trembled so hard so he hid it inside his pocket.
Spinal disc problems is a condition where the nerve between the spinal discs (spinal discs are the rubbery pads in between the vertebrae) are pressed together, along with the nerves that control the movement of hands and legs, which results of them moving without even the person knowing.
If you see the video, his legs also trembled hard.
He even fell that day during the ending part, he must be in pain..
Kai wasn't anywhere to be seen during the opening stage, so Suho tried to make the fans calm down by telling them that Kai was going to be late because he had some problems with his outfits.
But later, he came up to the stage wearing a cape, he looked like he was in pain while crying during the stage.
It looks very painful even just by looking at it, imagine how hard it must be for him..
-At first, Kai was sick so they decided to do the pre-recording just once. But after monitoring it, they were told to record once more, so they did.. and then Kai fainted, and Chanyeol cried.
-After Show Champion's Pre-recording, the fans were really worried because after the pre-recording ended, Kai couldn't even stand. So around 5 persons came up to the stage to help him, Suho explained that Kai has a spinal problems because of over-work. During the second pre-recording, Kai held onto Chanyeol arms and looked like he was almost crying while going off the stage.
(more gifs on the link)
-I'm a non-fan but my heart really hurts while reading thisㅠㅠㅠㅠㅠㅠㅠㅠ
-Let's be healthy and not get sickㅠㅠㅠㅠㅠㅠㅠㅠㅠ I'm so upsetㅠㅠㅠ
-Jongin-ah, it's nice to see you working hard to show us a good performance. But please take care of yourself firstㅠㅠㅠㅠ
-Of course it's cool, the fact that he danced while suffering from terrible painㅠㅠㅠ But I really hope he knows that his health must be his number one priority..
-Ah.. My heart hurts.. He should go and get treatment for itㅠㅠㅠ
-It's painful and hard even just to do simple things in life if you have spinal disc problems.. I hope he will get better soonㅠㅠ
-Take some rest..
-They should give them a break.. SM is over-working him..