I think Homer is referring to the Left Wrist during Impact Interval. In this case, the Left Wrist should always be Vertical/perpendicular to its associated Basic Plane, depending on the Hinge Action used -- Horiztonal, Vertical or Angled.
Palm faces plane for Standard Wrist Action (10-18-A). That's why Swingers need to Swivel -- Uncock then Roll -- to get ready to apply their selected Hinge Action (usually Dual Horizontal) at Impact.
With Standard Wrist Action . . . you are BEGINNING the UNCOCKING with the left palm facing the plane. BUT Full Lever Extension would be achieved until AFTER the Releease Swivel and Hinge Action, right? Since Full Lever Extension is at Low Point (of course assuming that Impact is not at Low Point).
Hybrid Mode
