[Yoda]

Fantastic - I guess it takes a little brainwork for all of us to get some of the concepts of the golfing machine. Hinge action - turning, rolling, swivel???

Hinge Action is the Left Wrist remaining Vertical to one of the Three Basic Planes. Swivel Action (or Wrist Action) is Turning or Rolling away from that Vertical condition.

With Horizontal and Angled Hinge Action, the Vertical Left Wrist appears to Roll through Impact. However, as long as the Wrist remains Vertical, there has been no independent rotation of the Hand (and hence no Swivel).