FWIW I don't think he was propped up when he got into the van so I don't think he was paralyzed at that time.
Here is the video that shot was taken from.
New video shows arrest of Freddie Gray in Baltimore Youtube video 2:34 April 21, 2015
Now that’s weird. The other YouTube video show him crumpled on his knees at the bumper as the lift him up and his head rolls back.
Yours shows him standing up briefly with his head straight at the same time and place as the other video was shot.
What the hell?!
Not only that he is yelling....kind of hard with a crushed larynx. He was not injured before being put in that van the van other that what being shot with a taser did to him.