Thank you for taking the time to reply. I receive the E-mails regularly from Steven, but only one E-mail mentions pronation as the action his arm/hand takes after throwing a changeup. The "palm down" vs pronation was imparted from a "visiting" source. I hadn't heard or read anything about this before and so I thought it was the latest trend. The videos were very beneficial (thanks for the links, got any more??), especially Drew Brees and how his hand goes from supination before delivery, to full pronation after delivery. Looking at the videos further reinforced my view that pronation is natural and necessary to prevent injury to junior pitchers.
I appreciate your input.