On several occasions reference has been made to Dr. Grober and his [size=130]Sonic Golf System[/size].
I have some time ago analyzed this system and it might be of interest to those who wonder what it measures and how it is done.
Well known golf scientists such a Dr. Jorgensen (The Physics of Golf) and Dr. Cochran et al. (Search for the Perfect Swing) came to the conclusion that the bigger muscles had to contribute significantly to obtain the observed club head speeds.
Their conclusion likely contributed to the view that the golf swing is primarily body driven and the present emphasis on the kinetic chain action.
However these scientists did not take into consideration the power contribution generated by the linear reaction forces in the wrist joints.
This makes the distinction between arms swing and body swing way less significant and also seems to make lag’s approach more easily to explain.
The kinetic chain concept is probably now part of mainstream thinking. It implies that proximal segments slow down sequentially and thus letting energy/momentum flow towards more distal elements.
lag’s approach however seems to neglect kinetic chain action by aiming for maximum pivot acceleration just prior, during and beyond impact. This inhibits the typical kinetic chain action.
One can consider a golf swing from different angles such as, for instance, efficiency, speed or accuracy. Using kinetic chain action is probably best for maximum efficiency.
Lag’s approach is not energy efficient but seemingly there is not much distance loss indicating that the role of kinetic chain action in golf is perhaps overdone a bit.
Dr. Grober’s measurements clearly indicate that the hands decelerate prior to impact which agrees with the kinetic chain concept.
Dr. Nesbit’s measurements however, if I remember correctly, seem to show substantially less deceleration for expert golfers.
In the linked [size=130]paper[/size] I have taken again a typical measurement done by Dr. Grober and derived some more information from it. There is indeed a significant deceleration of the hands during the down swing.
Imagine lagpressure using Grober’s Sonic System, with the suggested extensions, and quite likely being able to show how his swing exhibits a totally different behavior.
It would be very interesting indeed to have such comparative study done by an expert gofer, such a lag, who is able to swing in various ways and compare the resulting measurements.
Mandrin
I agree with this.But suppose on the top of a SF street which goes down and then rises back up. Regular swinging is like pushing briefly on the gas pedal with the car in overdrive and then letting go; you may or may not reach the top end of the street. Lag’s swing is like let the car drop in neutral and pushing the gas full throttle just before the bottom in 1st gear and keep throttling full speed to the top. Yes the enginge revs up into the red but you are sure of reaching the top.
Mandrin,
That is a great looking experiment and ideas that you posted…alas I don’t understand one bit of it 
anyhow besides all that
In all these tests or conclusions or thesis’s who is tested?
I am pretty certain they haven’t strapped Trevino, or Hogan or Nicklaus onto the hook ups and worked out what any of the great strikers actually did.
Is it based on anyone…who is used in tests…club pros?..amateurs?..touring pros on the Hooters Tour?..PGA Tour?..or hackers?
I think understanding the test parameters and who it was tested on would make some of that stuff more believable if we knew what type of students they used for the work or is it all machines?
I just get skeptical of all these tests facts figures until we know who is involved. Any test situation can be swayed to give the results we are looking for if the subjects are of the right arsenal to do so.
And out of curiosity 
I know you and Bio have butted heads …and… I know you are not one of Lag’s students so don’t know the full methods involved in what is being taught and achieved here at ABS…but Lag was subjected to Bio’s cube or measuring tool for testing… I don’t know if you know the cube/test zone he uses…Lag did the test straight out of bed in the morning when his body was less functional and active or warmed up…no practice swing…no stretching…nothing… and the results were apparently fantastic as far as the kinetic link and it’s workability and chain function was concerned… does that show anything about kinetic link and Lag’s teaching that you may be missing by saying his teaching isn’t exactly on the ball ?
Macs: That is one great description of feel regarding the passive lowering of the action from the top–probably one of the best I’ve ever heard. It does indeed feel like the clutch is being pushed in…ready to be “popped” at the correct moment.
Mandrin,
You are undoubtedly the expert when it comes to science around here, so I do hope you can answer some questions about the kinetic link.
- When you talk of the hands slowing down, are you talking about the distance the arc of the hands travel?
- Does your model only apply to a full swing? Because if I take a half swing, I know I can hit an impact bag much stronger with an aggressive and muscular uncocking and rotation of the wrists than if I sequenced the motion from the ground up and and let the uncocking of my wrists happen naturally.
- If we consciously tried to put on the brakes at impact, do you think this would increase our clubhead speed?
Thanks in advance for your feedback.
twomasters,
Just some Googling will readily convince you that Dr. Grober and Dr. Nesbit are trustworthy well respected golf scientists. Usually they take a batch of golfers of various skills, from hackers to pro golfers. If you have another peek at my post than you will notice that instead of saying “lag’s teaching isn’t exactly on the ball” I am rather mentioning, perhaps not very clearly, not being quite convinced that the kinetic chain model is all inclusive and explaining everything. Lag himself mentions somewhere that his approach is not optimum for distance hence seemingly in line with my comments. However it seems evident from results that lag’s approach is proof that there are still other quite different and useful avenues open for those who want to explore on their own. 
Nick,
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Slowing down reduces the rate of displacement vs time. As a consequence the hands travel a smaller distance than if they had not slowed down. From the super slow motion sequences, e.g. of Tiger Woods, shown during PGA events, it is clearly visible that close to impact the hands are slowing down appreciably and clubhead rapidly overtaking the hands.
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You have to be very careful comparing hitting golf balls with hitting impact bags. The collision of head and ball lasts for only 0.0004 sec. For an impact bag let’s say it takes about 0.4 sec. Hence the impact with an impact bag would take approximately 1000 times more time. Feeling wise it is hence clear that one can feel very readily the strong impact with the impact bag but can’t feel the same for the collision of clubhead with golf ball, way too short. A typical example of feel versus real.
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Joe Nichols with his rotary swing, “Rotor Method”, taught it and some tour players such as Mike Morley and Howard Twitty and several teaching pros adapted the method. I don’t feel that it is an good idea. The golf swing is a short duration intensive muscular activity and maintaining therefore almost simultaneously the feeling of both accelerating and decelerating would probably be detrimental for almost everyone. Tiger on a YouTube clip mentioned as a junior player, from the top, squatting down vertically first and subsequently rising up vigorously through impact. Here we have something similar. Two ideas, rather conflicting, and very difficult to execute optimally in a very short time span.
It seems common sense that a downswing should be one fluid interrupted motion. If a vigorous torque is exerted directly from the transition than automatically there is slowing down and all will take place without any conscious action. Feel and facts are usually so far apart in golf that science is not really a good golf instructor. Its findings should be used with care. Science is good as background information, not quite appropriate for detailed swing instructions. 