[O.B.Left]

Though the section on Hinge Action and the diagram of the Machine in 1-L depict the Hinge as being located at the swing center, the left shoulder, any of the Three Zones can reproduce Hinging ......and as if it were done at the shoulder.

Billy Casper had a very effective Zone 3, Hands only Vertical Hinge putting stroke for instance. Id venture that most pros today use a Zone 1 (Paw Minor Basic Stroke) Shoulder Stroke with Angled Hinging.

Homer was all about categorization so I guess you could say that any of the Three Zones on their own or any combination there of, could reproduce a Hinge Action.

The Machine of 1-L reveals the basic geometry only. The geometry of a "Hinge Action of an Angular Motion on an Inclined Plane". Homer didnt want us, Humans, to try and swing like his Machine! That is not what the book is about. The Machine can not " swing from the feet" for instance, or shift its weight, or tilt it shoulder axis or or or. But the geometry of the Machine holds, profoundly.