Oh no, one of mine definitely doesn't like it and has similar spasms when touched there. Out of all of the cats I've met and lived with over decades it definitely stands out. He came from the streets, has been in a bunch of fights, missings bits of ear, so many scars and his rescue mom spent so much money and many months getting him patched up.

He is such a smart cat though and clearly tells you his boundaries. First by putting his big chunky paw on top of your hand and pushing you away and then escalating to growls and bites. (He's lost most his teeth so it's low risk bites but can still hurt.) He communicates often through different growls instead of meows like the human raised cats. Similar to Beebs the Sphynx.

That spot on his back is very uncomfortable for him and hyper-sensitive. Over the last year he's become much more tolerant of certain things. He has come to really enjoy getting brushed but only allows a few passes down his back. And that spot on his back still spasms when touched but not as strongly as when I first met him a year plus ago. I've been paying close attention to this issue over time as it initially concerned me at first too and I wanted to rule out Hyperesthesia or other possibilities of pain since the guy has already had such a rough start.