[Mike O]

In my opinion, it's not a crucial issue in that it doesn't change the nature of the hinge action, it's one of the classification issues where it could be in either one. But it's been moved from zone #3 to zone #2- after Homer received feedback from teachers concerned that having it in zone #3 implied that Hinge Action was something you did with your hands- and since that's not the case (2-G 3rd paragraph- "The Physics of Hinging is, that, Hitting or Swinging, "Roll" is actually imparted by the turning torso and/or the orbiting Arms....), Hinging was moved to zone #2.