The principle of connection states that a hitter's hands, rather than extending through and making the Power V at the point of contact, rotate with their back shoulder through the Point Of Contact. Their hands and arms do extend on a good swing, but only after the Point Of Contact. At the Point Of Contact, a good hitter's back elbow and back knee will be bent 90 or so degrees and in the Power L position.
Yes, often combined with the front leg fanning open. This constitutes a system that has to be addressed as a system rather than as separate problems.Another thing that also causes this issue is a batters initial move. You have to get your swing started as the pitch is thrown. Many batters with bat lag will drop their hands as their first move and create bat lag.