Pedroia fighting off an inside pitch without stalling his elbow.
"Once you stop learning, you start dying" -- Albert Einstein.
My DD had the same problem..... What I believe was happening was, she would trigger the swing with her shoulders..... I guess you could say she was dragging the hands..... This cleared up when (or at least IMO) when she started focusing on the hands being in charge and letting the body support..... A cue that seemed to help her with this was “Allow the turn or transition of the barrel to open you”.....
Usually a stalled elbow is from poor hand usage in the beginning of swing launch. There is a ‘short hands’ video floating around this site. Give it a view. See if it makes sense. The reason why you don’t see a stalled rear elbow on the tee is the body’s angles are preset before launch because of knowing location of the ball before launch. I would encourage you to learn about hand path. It’s a must in a GOOD swing.
Review DRDRODDs post as well. The hands set up the body. Not the other way around.
Thanks in advance.