Given that many cats are walked in harnesses, I doubt that Kitty was paralyzed. I think he was just, well, being a cat.
When I was a kid, I tried to put a harness on my cat. He reacted the same as the one in the video.
I gave it up as unnatural...the cat made me see the errors of my ways.
I have trained several cats to walk on a leash in a harness. The trick is to start them young and get a cat harness. They wiggle out of the ones meant for dogs. They wiggle out of the ones meant for cats too just not quite as fast.
Next cat I am thinking of getting a "Kitty Holster". George T. Cat is now starting his 15th year of life and I don't think it would be fair to start trying to change things at this point.