That sounds like a very comfortable chair.
I read a book by Colleen Hoover, Verity - its about a writer who can't finish her book and needs to hire a ghostwriter.
Well, when the ghostwriter site on Verity's chair, she is instantly amazed at what a difference a chair makes. She makes a comment about how much of a better writer she would be if she was always comfortable.
I've been paying attention to chairs since I read that book :)
It does make a difference. If you're not comfortable, then you constantly are adjusting your position and interrupting your thoughts.