[Jeff]

12PB

The hand arc is not as circular as the clubhead path.

The only time that the hand arc can be circular is a swing where the left shoulder socket remains stationary in space - as demonstrated with that double pendulum swing model where the fulcrum remains stationary (and as seen in an Iron Byron machine).

A poor golfer may have a near-circular hand arc if he accelerates the hands from the top of the swing and starts the kinetic sequence incorrectly with a hand pull down motion.

Good golfers start the downswing with a lower body shift movement that causes secondary axis tilt => they then rotate the right shoulder downplane => that allows the left arm to be pulled down to the ball (via the release of PA#4) along an inside track. That produces an U-shaped hand arc - as demonstrated in this next photo of Tiger Woods hand arc.



The upper portion of the hand arc is very "straightish" and that doesn't induce a release phenomenon. The release phenomenon doesn't only depend on the radius of the hand arc curve; it also depends on the hand speed as it moves through that portion of the hand arc curve. Tiger's hands aren't moving very fast during the "straightish" portion of the U-shaped hand arc because he hasn't yet released PA#4. The speed of hand movement in the early downswing is determined by the speed of the pivot rotation - because the left arm is still kept across the chest wall (PA#4 remains loaded) and the power package is kept intact.

Tiger's hand speed becomes maximum when PA#4 is released and that happens when his hands are going around the bottom of the U-shaped hand arc. That means that his hand speed is maximum when the radius of the hand arc curve is smallest (tightest rounded curve) and that causes the passive release of the club. Although we commonly refer to this release as a centrifugal-induced release, a better explanation is nm golfer's mathematical explanation. Either way, the release is passive, and the "force" inducing the release is the circular motion of the fast-moving hands.

KOC - I do believe in 10-23-A - see above photo of Tiger Woods. I simply use the term 'straightish" because the hand arc can never be perfectly straight. However, it can be close to straight if the kinetic sequencing is correct. To prevent a circular hand arc path that promotes a sweep release, a golfer needs to induce a more U-shaped hand arc (like Tiger Woods) by making sure that the thrust-direction of the hands is in a straight line direction towards a desired aiming point (eg. ball or point ahead of the ball on the ball-target line) and the kinetic sequence is optimised.

Jeff.