MY 7.5 month old DS sits up beautifully on his own - for long periods of time - and really enjoys playing in that position. He can roll over both ways, and all over the place.
He prefers to be sitting though, and seems to get more frustrated rolling as if he can't do what he needs to do in that position.
Does sitting hinder crawling development? Is it better he's on back or stomach sometimes, even if frustrated, so he pushes himself to crawl...?
I have no clue about these things
And let me add, I'm not looking for him to crawl quickly for no good reason as I know my nice quiet life will end...