- do you think that the pelvis/shoulders/arms are rotating at roughly the same speed in the early downswing - before the lead arm reaches the parallel-to-the-ground position; or do you believe in the kinetic link theory where there is a time-sequential transfer of energy that causes the pelvis to move first, the shoulders second, and the arms third with each sequentially moving part maximally rotating at exactly twice the speed of the preceding moving part?
Jeff.
"the pelvis/shoulders/arms are rotating at roughly the same speed in the early downswing - before the lead arm reaches the parallel-to-the-ground position;"-- Lag being sustained.
"the kinetic link theory where there is a time-sequential transfer of energy that causes the pelvis to move first, the shoulders second, and the arms third with each sequentially moving part maximally rotating at exactly twice the speed of the preceding moving part"--Lag being thrownaway.
__________________ Yani Tseng, Go! Go! Go! Yani Tseng Did It Again! YOU load and sustain the "LAG", during which the "LAW" releases it, ideally beyond impact.
"Sustain (Yang/陽) the lag (Yin/陰)" is "the unification of Ying and Yang" (陰陽合一).
The "LAW" creates the "effect", which is the "motion" or "feel", with the "cause", which is the "intent" or "command".
"Lag" is the secret of golf, passion is the secret of life.
Think as a golfer, execute like a robot.
Rotate, twist, spin, turn. Bend the shaft.
__________________ Yani Tseng, Go! Go! Go! Yani Tseng Did It Again! YOU load and sustain the "LAG", during which the "LAW" releases it, ideally beyond impact.
"Sustain (Yang/陽) the lag (Yin/陰)" is "the unification of Ying and Yang" (陰陽合一).
The "LAW" creates the "effect", which is the "motion" or "feel", with the "cause", which is the "intent" or "command".
"Lag" is the secret of golf, passion is the secret of life.
Think as a golfer, execute like a robot.
Rotate, twist, spin, turn. Bend the shaft.
Stands for Conservation of Angular Momemtum (I alpha^2) where alpha is angular acceleration.
At the top of the back swing... How much angular momentum is there?
1/3 of the way down.. How much?
Half Way down?
and at impact?
Easy right? At the top there is none... zero... zip... nada. Things are stopped. 1/3 of the way down... There is some.. things have begun to move
1/2 way down... There's even more... now the golfswing is really picking up speed and starting to rotate fast. Finally at impact? Maximum momentum, maximum rotation *that is unless you subscribe to some ignoramus teacher's ridiculous theory of kinetic chain snapping in which case you've probably lurched yourself to a halt and incurred a mishit*
If angular momentum is increasing as the downswing progress' all but the dimmest among us must agree, then by definition angular momentum it is NOT being conserved. (If as time progresses you have more or less of somthing it is NOT being conserved). COAM does not apply to the golfswing and I refer you to any physics or mechanics textbook if you disagree with this definition of COAM.
Dante wrote a pretty good book back in the 60's (5 magic moves). In it he had stroboscopic pictures of one golfer whose hands slowed down before impact (they almost came to a halt in fact). Dante extrapolated from his sample of one (never a good thing to do btw) to all golfers.
Since he did not know how to explain this observation himself, Dante consulted a physics teacher who told him the golfers hands slowed down because of COAM (sounds good in theory.... but wrong ... for the reason given above). Also note the: "Appeals to authority" logical fallacy. He's a physics teacher so he knows right? wrong. Perhaps Dante should have consulted with more experts to confirm the firsts explanation and golf instruction would not be mired in this COAM myth. Hind sight is of course 20-20.
It turns out very few people swing a golf club like Dante's stoboscope model anyway. In fact Nesbit's data shows most golfers (especially the better ones) accelerate their hands all the way to impact. (See figure 4 http://www.motionanalysis.com/pdf/2005_nesbit.pdf ) BTW... Nesbit used the finest "3d machine" available to acquire his measurements. Some people choose to ignore that which does not fit their preconceived notions especially slayers of windmills.
PS
Check out fig. 7 of the linked pdf. That's angular velocity. For those who did not make it to (or forgot) calculus, the slope of that curve is angular acceleration. Note its increasing for all golfers right up to impact. Angular momentum IS NOT being conserved during the golf swing. Have a good day!
Last edited by no_mind_golfer : 10-31-2008 at 07:39 PM.
Use e.g. a V1 software. Use the Spline feature. Use the same time intervals and mark hands position each time. You will see (no matter what golfer - used even Ben Hogan driver FO vid) that the hands are initially accelerating, then slowing a bit before coming into the impact zone.
I know that it's an imprecise tool but it rather confirms what Dante discovered, not your revelations, Nm.
I am very objective. Try it yourself before you start negate what I tried.
I believe Nesbit's test data not your V1 software spline feature.
Drawing on stills or footage never made any sense to me anyway .... parallax etc. But you're free to believe what every you want to believe.
There there are undoubtly some golfers who's hands slow down some (Nesbit measured some golfers whose hands did) but very very few golfers hands slow to the extent of Dante's stroboscope model.
Its not worth my time discussing this hand speed issue anymore (as you know it was beat to death on that other forum).... the DATA speaks for itself and the DATA SAYS GOLFERS HANDS DO NOT NECESSARILY SLOW DOWN BEFORE IMPACT. (see figure 4 in linked pdf) Read Nesbit's comments on matter. Either you believe it or you don't end of story.
Originally Posted by Dariusz J.
Use e.g. a V1 software. Use the Spline feature. Use the same time intervals and mark hands position each time. You will see (no matter what golfer - used even Ben Hogan driver FO vid) that the hands are initially accelerating, then slowing a bit before coming into the impact zone.
I know that it's an imprecise tool but it rather confirms what Dante discovered, not your revelations, Nm.
I am very objective. Try it yourself before you start negate what I tried.
Cheers
Last edited by no_mind_golfer : 10-31-2008 at 07:40 PM.
It's not the question of my belief. I always tried to be objective and love the objective truth. Thus, I take seriously Mr.Nesbit's researches as well as e.g. Mr.Dante's ones. However, there is no final evidence for one or the other theory - otherwise, the discussion on this or the other forum would not have been necessary.
You can laugh at my V1 trial - and I understand it because I myself stated that it's a imprecise tool - but, it shows what it shows. This is what I wanted to say, nothing more.
Linear Mode
