Thanks for the replies, advice and suggestions.

Yeah Gina, I know, I didn't want to make a thread, but I was curious about arthritis and if a vet can diagnose it. (I could have just asked my sister, a vet tech. )

I think I'm just going to see how he does, since I can't take him to the vet until next week anyway. He seems perfectly fine, running around like usual. I'm probably just feeling a bit of guilt (for hitting him with the door) and just being a paranoid meowmie. He is my one and only heart cat.....EVER.

Thanks again you three!