Back sholder bones touching

I am wanting to know if this is normal for cats...I have a 4 1/2 month old kitten that is very thin but he weighs 5lbs 8 oz. He is very long and lean. I noticed that his sholder blades touch eachother...it's like there is nothing between them. It is only like this when he is sitting up. I asked my vet and he said he is actually pretty big for his age but he is so skinny!!!
Is it normal for their sholder baldes to touch like that??

If the vet didn't have a concern, I wouldn't worry. Is this cat neutered? This can affect muscle growth/development in male cats and it may just be lack of muscle in the cat.

Lselie