Todd -- wouldn't each of those Top 100 videos show a golfer whose lead shoulder is rising through the impact zone, thus pulling the extended lead arm/hand attached to that shoulder upward and inward?
Dear puttmaster,
Great comment and observation.
In 2007, when I first got curious about ground reaction forces and how in golf they were created, I actually took the fold-out swing sequences in the golf magazines, and with engineering tracing paper, drew the position of the lead shoulder sequentially from each frame for both the head on, and down the line views.
For sure, the lead shoulder is going up (or sometimes and unfortunately horizontally for amateurs), and for good reason. From simple geometry, the angle between the arms and the club at address and impact are different necessitating ALWAYS, a movement of the lead shoulder to a more distant location at impact thru full extension of both arms.
This is the time period being discussed here, and another VERY important relevant point is to be made from physics, not geometry.
For a golfer hitting a driver with a swing speed of 100 miles per hour at impact, the centripetal force needed to be keep the club stably on its 'flight path' is almost exactly 100 pounds, and easy to remember. Since the force is a 'square function' with the velocity, a 110 MPH swing develops 121 pounds of force, a 90 MPH, 81 pounds of force etc.
My point is the effect on STABILITY of the flight path of the club. If that centripetal force is not RESISTED exactly, the club will drift AWAY from the intended path. Conversely, if MORE than the centripetal force is exerted on the grip in a pulling direction, the path will be changed, but the physics suggests that 'parametric acceleration' will occur, with a resultant increase in club head velocity.
So, IMO, even though subjective, throwing the club head off the shaft, and pulling on the shaft could result in very different club head dynamic, and flight path conditions.
Sincerely,
art
