Move the club up and down with arms, around with the body
Maude, relaying Pete Cowen's insights, clarifies the division of labor in the golf swing: the arms are responsible for moving the club up and down, while the body is responsible for turning the club around. A big flaw is letting the arms do the 'around' motion and then adding the body turn on top of it, which leaves you completely out of position. Keep the arms working up-and-down and let the body supply the rotation.
Channel: Danny Maude
Watch official source at 0:52Why this context matters
From a driver lesson in which Maude relays Pete Cowen's emphasis on controlling the trail side.