I would say Finish Swivel begins somewhere around when the left arm passes the left shoulder socket thingie.
Hinge Action -- holding the Left Wrist Vertical (or perpendicular) to one of the three Basic Planes (Horizontal, Vertical or Angled) -- is in operation from Impact to the end of the Follow-Through (Both Arms Straight position) per 7-10. The Arms will be well-extended past the Left Shoulder and the Clubshaft will be about 45 degrees to the ground. Then, Swivel Action -- "Snap Rolling the Hands into their On Plane Condition" (2-G; 4-0; 4-D-0) -- takes over as the Left Wrist Rolls from its Vertical alignment and creates the bridge to the Finish (12-3 #41).
In essence, Hinge Action is an Arm Motion (for Clubface Control) whereas Swivel Action is a Wrist Motion (for Clubhead Control).
Hinge Action -- holding the Left Wrist Vertical (or perpendicular) to one of the three Basic Planes (Horizontal, Vertical or Angled) -- is in operation from Impact to the end of the Follow-Through (Both Arms Straight position) per 7-10. The Arms will be well-extended past the Left Shoulder and the Clubshaft will be about 45 degrees to the ground. Then, Swivel Action -- "Snap Rolling the Hands into their On Plane Condition" (2-G; 4-0; 4-D-0) -- takes over as the Left Wrist Rolls from its Vertical alignment and creates the bridge to the Finish (12-3 #41).
In essence, Hinge Action is an Arm Motion (for Clubface Control) whereas Swivel Action is a Wrist Motion (for Clubhead Control).
Horizontal is the ground- flat. Vertical is a wall 90 degrees to horizontal or incline- perpendicular Angled is a roof attached to the horizontal plane at any degree- incline
Horizontal- Inclined Plane line, Stance Line, Target Line, Low point Plane Line (under the ground but horizontal and flat) Angled- Basic Plane angles for clubshaft control-incline plane angles such as Elbow or Shoulder. Vertical-Any and ALL perpendicular motions in the golf stroke and conceptually the toughest one to recognize. It is all perpendicular, vertical or ninety degree angles. The “wall” can be at alongside your hip or behind your back – perpendicular to the ground or it can be mounted perpendicularly to an incline plane. This is where it is attached when the Left Arm Flying Wedge throws out Accumulator Number two. All Vertical motion is ninety degrees to this vertical wall.