Golf swing and playground swing

[mandrin]

Rob Atkins in his Golf Digest article - ‘The Swing of the Future’ - refers to a move which he called the ‘spine-tilt thrust’.

“Most instructors will tell you the swing of the new golfer-athlete is one that synchronizes the swinging of the hands and arms with the turning motion of the body.
That's all fine and good. But after years of studying the swing, I've found one more critical element. I call it the spine-tilt thrust, and it happens right at impact. I'm convinced that adding this move to the arm swing and body turn will help you hit the ball consistently straight and far -- especially under pressure.”
-----------------------
“But if you get your body behind the hit, you have a driver that can weigh as much as you do. The spine-tilt thrust not only helps you effectively apply your body weight to your driver at impact, it will allow you to multiply that weight.”
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“WHEN TO DO THE SPINE-TILT THRUST: As the club contacts the ball, your left shoulder and hip should be jutting toward the sky. That's when the right foot should push off the ground and the left leg should stiffen. Don't do this too early. Wait for impact to make this split-second move.”
----------------------------

Above is a typical example of golf instruction. It is perhaps based on experience and intuition but the explanations given don’t hold much water. You cannot make your driver weigh as much as you do and neither will the spine-tilt thrust allow you to multiply its weight even further at impact.

A more realistic explanation should have invoked mechanisms such as :
- A bracing of the lead side which allows a more efficient energy transfer in the kinetic chain.
- An upward movement of the swing center, through impact, increasing the clubhead speed.

The lead side lower body acting as a solid wall to hit against allows the kinetic energy/angular momentum to be more efficiently transferred to the distal elements such as the clubhead.

The straightening of the lead knee and the upward jutting of the lead hip/lead shoulder is at the heart of a little known mechanism even if we have all done it as kids on playground swings.

For those who might be curious what they did as a youngster but have forgotten all about it playing golf as adults should have a look here to refresh their memory.

 

[vjcapron]

I agree

This article was "complete junk"! I couldn't believe what I was reading.

 

[mandrin]

This article was "complete junk"! I couldn't believe what I was reading.

vjcapron, I would be interested to know what you considered junk in this article. You are not very generous with reasons given.

 

[birdie_man]

I like the idea....of the article.....it's just Axis Tilt. mandrin's prolly right about the science.

 

[mandrin]

I like the idea....of the article.....it's just Axis Tilt. mandrin's prolly right about the science.

Birdie man,

Rom Atkins is convinced that one can effectively augment the effective mass of the clubhead.

This notion, I feel, is equally inherent in the TGM guidelines - 'heavy feel', 'impact deceleration'.

If you agree with me does that mean that you feel that one cannot resist impact deceleration?

 

[jmessner]

Birdie man,

Rom Atkins is convinced that one can effectively augment the effective mass of the clubhead.

This notion, I feel, is equally inherent in the TGM guidelines - 'heavy feel', 'impact deceleration'.

If you agree with me does that mean that you feel that one cannot resist impact deceleration?

Not Birdie man, but interesting timing because I just posted about this amoung other things in the other TGM forum and brought up the Cochran & Stobbs work that showed that the clubhead acts as if it's disconnected from the shaft during impact - and therefore resesting impact deceleration is not possible. Didn't get a lot of agreement over there.

 

[birdie_man]

Birdie man,

Rom Atkins is convinced that one can effectively augment the effective mass of the clubhead.

This notion, I feel, is equally inherent in the TGM guidelines - 'heavy feel', 'impact deceleration'.

If you agree with me does that mean that you feel that one cannot resist impact deceleration?

I think so....you mean STLOC?

...

I'm not entirely sure....I'm no science whiz.....so really I can only go by what's in Homer's book....and apply my own limited logic from my experience. Makes sense to me tho right now.

...

I know the clubhead doesn't get physically heavier....

...

...

Ya, right now I think STLOC is a good concept.

I was just thinking that maybe the only reason why a strike would feel heavier is because you deloft the club more (with a Flat Left Wrist and some Lag)....

But then I thought.....ok....assuming I hit the sweetspot each time.....I can add loft and still have that compressed feel......if I have a good swing.

i.e. or I can hit a PW (it has more loft to begin with).......it will still feel compressed.

.....

Then my dad can hit a 5 iron.....and I can hit a PW (my normal PW....when I'm not trying to hit it high.....goes about the same height as his 5 iron- he flips a bit.....)....the sound is different....

I don't think it's just because my swingspeed's higher. He's a good golfer....about 5-6 hdcp these days. He swings driver about 100....I'm 115-120 or w/e...

...both of us hit em on the sweetspot...but something different happens...regardless of loft.

....

I'm all ears to your argument tho.

 

[mandrin]

Not Birdie man, but interesting timing because I just posted about this amoung other things in the other TGM forum and brought up the Cochran & Stobbs work that showed that the clubhead acts as if it's disconnected from the shaft during impact - and therefore resesting impact deceleration is not possible. Didn't get a lot of agreement over there.

jmessner,

You will not get very enthusiastic reactions here either. It has been discussed previously. You can search for the topic in the archives.

 

[jmessner]

jmessner,

You will not get very enthusiastic reactions here either. It has been discussed previously. You can search for the topic in the archives.

Got it. It only took me one old thread to see this topic has been hashed through with little productive result. These science and physics discussions sure generate a lot of reaction.

 

[mandrin]

musical ear

I think so....you mean STLOC?

...

I'm not entirely sure....I'm no science whiz.....so really I can only go by what's in Homer's book....and apply my own limited logic from my experience. Makes sense to me tho right now.

...

I know the clubhead doesn't get physically heavier....as he seemed to suggest.......or at least as he wrote it- it could make someone think that.

...

...

Ya, right now I think STLOC is a good concept.

I was just thinking that maybe the only reason why a strike would feel heavier is because you deloft the club more (with a Flat Left Wrist and some Lag)....

But then I thought.....ok....assuming I hit the sweetspot each time.....I can add loft and still have that compressed feel......if I have a good swing.

i.e. I can hit a PW (it has more loft to begin with).......it will still feel compressed.

.....

Then my dad can hit a 5 iron.....and it won't be as compressed as my PW (my normal PW....when I'm not trying to hit it high.....goes about the same height as his 5 iron- he flips a bit.....)....the sound is different....

I don't think it's just because my swingspeed's higher. He's a good golfer....about 5-6 hdcp these days. He swings driver about 100....I'm 115-120 or w/e...

...both of us hit em on the sweetspot...but something different happens...regardless of loft.

....

I'm all ears to your argument tho.

birdie_man,

The sounds associated with a well struck golf ball are indeed rather special. One can have various type of sounds such as clicking, sharp cracking, and there is that dull thumpy type sound.

They say Ben Hogan's sound was different and the sound included the hitting of the ground, a deep thump included with the sharp crack, people said you could actually feel the ground vibrate.

One might perhaps think of the clubhead surface as some type of musical instrument, having a typical dimensional structural resonance frequency, and likely optimally excited by an on-center hit with the golf ball.

Now is the sound typically and primarily generated when the direction of movement of the COG of clubhead, at impact, coincides closely with the line connecting the COGs of ball and blade?

Is there perhaps also a difference in the type of sound generated when the hit is not on the center of gravity but rather on the center of percussion of the clubhead ........ intriguing questions.

It could be indeed an interesting study to do a frequency analysis of the various types of sounds and than try to correlate it with the type of impact. Needs a golfer who can readily control impact conditions.

If indeed there existed a significant relation one could start thinking in terms of an acoustical bio-feedback learning tool perhaps especially useful for golfers with a musical ear.

 

[tourdeep]

without a doubt, our senses dictate choice.

 

[EdZ]

Sounds like he is talking about the 'result' of having what I call "full body impact" - extending the swing radius to the feet, with proper timing.

To suggest this is anything you must 'do' or 'time' is absurd and will really mess up a lot of folks who try.

 

[mandrin]

Sounds like he is talking about the 'result' of having what I call "full body impact" - extending the swing radius to the feet, with proper timing.

To suggest this is anything you must 'do' or 'time' is absurd and will really mess up a lot of folks who try.

EdZ, I feel that you are referring to the action of an effective kinetic chain, using the whole of the body, from the ground up, to help generating efficiently club head speed.

However, people like Rob Atkins do think that you can effectievly increase the effective mass of the clubhead by getting somehow the body mass involved.

“But if you get your body behind the hit, you have a driver that can weigh as much as you do. The spine-tilt thrust not only helps you effectively apply your body weight to your driver at impact, it will allow you to multiply that weight.”

 

[EdZ]

EdZ, I feel that you are referring to the action of an effective kinetic chain, using the whole of the body, from the ground up, to help generating efficiently club head speed.

However, people like Rob Atkins do think that you can effectievly increase the effective mass of the clubhead by getting somehow the body mass involved.

“But if you get your body behind the hit, you have a driver that can weigh as much as you do. The spine-tilt thrust not only helps you effectively apply your body weight to your driver at impact, it will allow you to multiply that weight.”

The body mass 'can' be involved, especially for a hitter.

 

[mandrin]

free body?

The body mass 'can' be involved, especially for a hitter.

EdZ, your statement is so general that it looses meaning. Body mass is always involved in a golfswing. The question however is exactly how re to impact.

Mindy Blake, with an engineering and teaching background, has expressed his idea very clearly in two books, ‘The Golf Swing of the Future’ and ‘Golf – the technique barrier’. It is based on assumption the clubhead not being a free-moving body during collision when ball and clubhead travel together. He is convinced that it is not the clubhead speed but instead the pressure applied through impact which determines the ball departure velocity.

Ike S Handy, another golf author - ‘How to hit the golf ball straight’ - is also very clear – ‘No degree of speed in the clubhead will supplant the power of swinging the weight of the body into the stroke’. Also, 'The slower, or more deliberate the downswing of the hands and the top of the club, the more perfectly and completely the weight of the body flows into the stroke'.

With Homer it takes the form of being able to resist deceleration of the clubhead during the impact interval and hence based also on the same belief that the clubhead is not a ‘free body’ at impact. He refers to centrifugal shaft stiffening and shaft stiffening, due to prestressing, being cause for resistance to impact deceleration. Hence including both swinging and hitting procedures.

The body mass involvement is indeed a perfect example of the rather sharp opposition which can exist between our intuition and a scientific analysis. My opinion is clear and expressed through various posts. I don’t want to start another debate but I am interested to hear what you think of it all.

 

[Biffer]

Mandrin,

Your quote.
"Mindy Blake, with an engineering and teaching background, has expressed his idea very clearly in two books, ‘The Golf Swing of the Future’ and ‘Golf – the technique barrier’. It is based on assumption the clubhead not being a free-moving body during collision when ball and clubhead travel together. He is convinced that it is not the clubhead speed but instead the pressure applied through impact which determines the ball departure velocity."

Could you please comment on what you believe Blake means in the last sentence? I know from experience with a launch monitor that clubhead speed and pressure are both important factors. Maximum pressure on the correct spot on the clubface is most desireable. Seperate swings at the same identical speed, but contacting different locations on the clubface can yield different ball speeds (we call it power transfer).

 

[EdZ]

EdZ, your statement is so general that it looses meaning. Body mass is always involved in a golfswing. The question however is exactly how re to impact.

Mindy Blake, with an engineering and teaching background, has expressed his idea very clearly in two books, ‘The Golf Swing of the Future’ and ‘Golf – the technique barrier’. It is based on assumption the clubhead not being a free-moving body during collision when ball and clubhead travel together. He is convinced that it is not the clubhead speed but instead the pressure applied through impact which determines the ball departure velocity.

Ike S Handy, another golf author - ‘How to hit the golf ball straight’ - is also very clear – ‘No degree of speed in the clubhead will supplant the power of swinging the weight of the body into the stroke’. Also, 'The slower, or more deliberate the downswing of the hands and the top of the club, the more perfectly and completely the weight of the body flows into the stroke'.

With Homer it takes the form of being able to resist deceleration of the clubhead during the impact interval and hence based also on the same belief that the clubhead is not a ‘free body’ at impact. He refers to centrifugal shaft stiffening and shaft stiffening, due to prestressing, being cause for resistance to impact deceleration. Hence including both swinging and hitting procedures.

The body mass involvement is indeed a perfect example of the rather sharp opposition which can exist between our intuition and a scientific analysis. My opinion is clear and expressed through various posts. I don’t want to start another debate but I am interested to hear what you think of it all.

All are talking about proper lag pressure IMO.

Of "SUPPORTING the on plane swinging force in balance"

The 'free moving clubhead' is throw away resulting from over acceleration, improper rhythm, and improper aiming point IMO, but as you said, we have been down that road.

 

[mandrin]

EdZ, I had hoped that, having an engineering background, you would have stayed away from answering right out of the ‘book’.

Lag pressure, staying on plane, over acceleration, improper aiming point , etc., are all very important but don’t address the essential issue here, which is:

Can one during the 0.0004 sec of impact interval increase ball departure velocity by applying force, hence accelerating, through the impact interval.

EdZ, let’s simply agree not to agree, since I feel that you are not quite open to the science involved explaining collision phenomena.

 

[mandrin]

'high-pressure-swing'

Mandrin,

Your quote.
"Mindy Blake, with an engineering and teaching background, has expressed his idea very clearly in two books, ‘The Golf Swing of the Future’ and ‘Golf – the technique barrier’. It is based on assumption the clubhead not being a free-moving body during collision when ball and clubhead travel together. He is convinced that it is not the clubhead speed but instead the pressure applied through impact which determines the ball departure velocity."

Could you please comment on what you believe Blake means in the last sentence? I know from experience with a launch monitor that clubhead speed and pressure are both important factors. Maximum pressure on the correct spot on the clubface is most desireable. Seperate swings at the same identical speed, but contacting different locations on the clubface can yield different ball speeds (we call it power transfer).

Biffer, applying pressure/force and their point of application are two different things. You seem to have in mind more hitting it or not squarely on the sweet spot (center of percussion). This is distinct from the act of applying a force through impact.

I am really at a loss how an engineer can possibly write such things as that it is not the clubhead speed but instead the pressure applied through impact which determines the ball speed. He distinguishes between a conventional ‘high-speed swing’ and his ‘high-pressure-swing’.

The 'high-pressure swing' is a slow deliberate swing exerting maximum pressure at impact. He believes, (no evidence, only opinion), that the ball separation speed is higher this way. This is similar to HK. Moreover he believes that the ball and clubhead stay than together longer.

He believes that by swinging slower than a ‘high-speed-swing’, but instead accelerating through impact, that there is no loss in distance and moreover an increase in accuracy. He therefore also believes that the bending of the shaft is part of the deal.

Mindy Blake, an engineer and scientist, is claimed being the first having made a scientific study of the body mechanics of the golf swing. He had a 2 handicap and 280 yard drives at the age of sixty-seven.

Golf can do strange things once the passion for golf is strongly entrenched and seemingly even obscure the mind of a well known engineer and war hero. Even a simple calculation should have shown him the truth.

 

[Biffer]

Mandrin,
Thanks for the clarification. I misunderstood the reference. So. now I have an additional query. Is this scenario correct? The amount of "pressure" is dependent on the velocity and the mass of the clubhead at impact, which produces a certain amount of ball speed. In order to change the amount of "pressure", it would be necessary to change the clubhead velocity or mass. Is that the idea?