[Daryl]

I don't think that HK was against using the Wrists. He did say that the muscles of the Forearms "Are Available" to uncock the Left Wrist. On the other hand, references about using the procedure are nonexistent in the book.

6-B-2-0 THE SECOND POWER ACCUMULATOR When the Left Wrist is Cocked (in excess of the selected Clubshaft-Left Hand Angle (6-B-3) in the Address Fix positions) it forms the Second Power Accumulator. It’s the true Velocity Accumulator because of the shortness of its travel time (during a Maximum Delay Release). Centrifugal Force, Accumulator #1, the muscles of both forearms, any – or all – are available to actuate this Assembly. Its “in-line” condition is FULL EXTENSION as determined by the Accumulator #3 requirements – if any. It is the “Downward” (Angle of Attack) Motion per 2-C-0 and 2-N-1.

Also, Jorgensen's study ("The Physics of Golf"), tested the use of active wrists with his double pendulum model and concluded that the procedure reduces Clubhead speed unless a Golfer is Skilled enough to actuate them within 70 milliseconds of Impact. He concludes that if it's possible, it's effectiveness is only marginal and lacks the speed increase of a delayed release procedure.