I have a student, who's buddies tell him to pull from the
top with the left arm. I tell him that this is incorrect, that
the left arm is inert with not much power. I recommend that
he start the downswing with shift/pivot/hip rotation. The
student says that he can't move the downswing with the
shift/hip turn, says it hurts his right hip. He insists that the
pull with the left arm makes him pivot.
How do I explain to the student that pulling with the left arm
does not make the pivot happen?