Anyone interested in finding more club head speed (which is everyone one would assume) should read the following then follow their work. I'm telling you there is GOLD in the pot at the end of that rainbow.
Reducing radius is the key and there are many ways to skin that cat. El Tigre "snaps" his left leg and is so doing move the left shoulder socket up. That's probably not the best way though lest ye too eventually need surgery.
Forget about "snapping your kinetic chain" (its bs anyway) learn to control your HAND PATH!
It may be a term Nesbit invented I don't know but that doesn't matter.
Think of a wagon wheel. YOu have a rim and you have spokes extending to the hub (which has a certain radius). Now look at figure 2 of : http://www.motionanalysis.com/pdf/2005_nesbit.pdf . Those are diagrams of golfer swings (Think of each club freezeframe as a spoke with the head on the "rim" and the grip end on the "hub".
So the Hub is the "path" your hands take from the top down to and beyond the ball. The "instantaneous" radius of that path is what matters. You want it to decrease (This is what prevents casting and maximizes club head speed). If you fit a curve to that hand path of a better golfer it would look like a contracting spiral.
We have determined that there are relationships that exist between the changing radius and club head velocity, applied force, torque, work, and power, and that even a small change in hub path and wrist trajectory values can increase club head velocity.
We already know the #2 accumulator gives velocity power so it would seem that the radius is shorter until the point where the wrists begin to uncock and after that point the radius lengthens. That's why people who cast from the top lose power and tend to hit fat shots, they just made the club longer.
My 2 cents worth.
__________________ Hitting the Ball is the easiest part of the game-hitting it effectively is the most difficult. Why trust instinct when there is a science."1-G.
In that experiment the student is using a loudspeaker which tugs up and down on the pendulum string at just the right frequency in order to increase the amplitude. Its called parametric acceleration.
The same principle can be used to extract energy. When the phasing is such that it extracts energy, its sometimes called: active vibration control or active vibration damping. What's this have to do with golf in general and this thread in particular?
Its the same.
When the club is releasing it is like a pendulum, the club is swinging about a point at the wrists. While we cannot shorten the length of the club shaft during the swing we can apply more centripetal acceleration than is needed to keep the club rotating. We can tug "UP" at just the right time thereby injecting kinetic energy to the club head. When done in the final stage of the downswing this is effectively the same thing as "reducing the hand path radius". In 2002 a Japanese scientist wrote a paper proving the amazing efficacy of this technique to increase club head speed called: Parametric Acceleration in Golf Swing.
All long hitters do it. They may not know they're doing it ... but all long hitters inject that final dose of energy by "pulling up" at the end of the downswing. Some even end up on their toes as a result like Bubba.
One interesting bit of data reported by Nesbit is that a wide range of players have almost exactly the same hand speed profile (bottom set of curves on link below notice its not slowing as others suggest either but that's another issue)
Their hand velocity profiles are nearly identical yet clearly some swings are much more effective than the others. What's the difference? Its the path their hand follow reducing radius vs. non-reducing (or even increasing) radius... its pulling up at at the last second vs. not pulling up..
Its all in the hands folks... use your body to make your hands go where they've got to go.
Last edited by no_mind_golfer : 12-06-2008 at 10:00 PM.