The importance of ground forces in the downswing
- Thread starter James Marshall (Hogan1953)
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Thanks Spktho. With that snippet, I found the orginal thread:
http://www.brianmanzella.com/forum/...-ground-reaction-forces-angular-momentum.html
http://www.brianmanzella.com/forum/...-ground-reaction-forces-angular-momentum.html
James Marshall (Hogan1953)
New member
Mandrin,
Thanks for your invaluable input. Are you saying here that the unbending right arm is adding and redistributing but the uncocking wrists are merely redistributing?
mandrin
New
Hogan1953,
Thanks.
Your interpretation is indeed quite correct.
The unbending trail arm, involving trail shoulder and some upper body, is both injecting and redistributing angular momentum.
Active wrist torque does not inject net angular momentum into the golfer club ensemble. The reason being that no appreciable ground reaction force is being generated.
If one can create some low friction surface, then one can, feel wise, readily identify the 'degree of connection' for various motion, by observing possible feet movements.
birdie_man
New
Very interesting. I want to try it...! Wish me luck. (slip fall crack...coconut milk leaking...)
birdie_man
New
From who??? ... certainly NOT from me ..!!!!
Steve you would have to show your face!!
Oh dear. All in good fun...
But wouldn't how you use the ground have a big effect on whether you apply those forces to the clubhead/ball as opposed to throwing them away? Using the ground well is more about conserving the energies (until the right moment) rather than generating them?
There's just something to the feel of "effortlessness" from a well grounded swing that must have something to do with greater efficiency.
mandrin
New
cnadon,
I sympathize as frequently ground forces are dealt with in a very vague and purely intuitive way. I am not aware of anyone analyzing ground forces as I have done. Hence it takes a bit of exposure before a very different way of looking at this matter seems to make sense.
I kind of feel in your questions the frequent vague notion of some ground force into which one can tap to increase power in the golf swing. It is kind of suggested by golf instruction when claiming having a method to efficiently exploit ground forces.
This however is approaching the golf swing in a tipsy topsy way. Ground forces do not have an existence independent of a golfer but are rather generated by the golfer himself. A weak swing generates weak ground forces and a power full swing strong ground forces.
Basically the input power comes from the torque, caused by the shear forces between feet and earth. But simultaneously the normal forces between feet and earth should generate enough friction to prevent slip. Some brisk upward motion will increase dynamic weight and hence friction forces, if so desired.
Perhaps not very exiting but there is no esoteric method to suck mystique power from the earth. The feel of "effortlessness" from a well grounded swing, you refer to, is due to hard work having resulted in proper technique. Mother earth is perhaps generous but does not know much about golf.
cnadon,
I sympathize as frequently ground forces are dealt with in a very vague and purely intuitive way. I am not aware of anyone analyzing ground forces as I have done. Hence it takes a bit of exposure before a very different way of looking at this matter seems to make sense.
I kind of feel in your questions the frequent vague notion of some ground force into which one can tap to increase power in the golf swing. It is kind of suggested by golf instruction when claiming having a method to efficiently exploit ground forces.
This however is approaching the golf swing in a tipsy topsy way. Ground forces do not have an existence independent of a golfer but are rather generated by the golfer himself. A weak swing generates weak ground forces and a power full swing strong ground forces.
Basically the input power comes from the torque, caused by the shear forces between feet and earth. But simultaneously the normal forces between feet and earth should generate enough friction to prevent slip. Some brisk upward motion will increase dynamic weight and hence friction forces, if so desired.
Perhaps not very exiting but there is no esoteric method to suck mystique power from the earth. The feel of "effortlessness" from a well grounded swing, you refer to, is due to hard work having resulted in proper technique. Mother earth is perhaps generous but does not know much about golf.
You mean the "secret" isn't in the dirt?, damn.
Welcome back, it's been a while, what have you been up to?cnadon,
I sympathize as frequently ground forces are dealt with in a very vague and purely intuitive way. I am not aware of anyone analyzing ground forces as I have done. Hence it takes a bit of exposure before a very different way of looking at this matter seems to make sense.
I kind of feel in your questions the frequent vague notion of some ground force into which one can tap to increase power in the golf swing. It is kind of suggested by golf instruction when claiming having a method to efficiently exploit ground forces.
This however is approaching the golf swing in a tipsy topsy way. Ground forces do not have an existence independent of a golfer but are rather generated by the golfer himself. A weak swing generates weak ground forces and a power full swing strong ground forces.
Basically the input power comes from the torque, caused by the shear forces between feet and earth. But simultaneously the normal forces between feet and earth should generate enough friction to prevent slip. Some brisk upward motion will increase dynamic weight and hence friction forces, if so desired.
Perhaps not very exiting but there is no esoteric method to suck mystique power from the earth. The feel of "effortlessness" from a well grounded swing, you refer to, is due to hard work having resulted in proper technique. Mother earth is perhaps generous but does not know much about golf.
Thanks for the reply Mandrin. I'm no mother/gaia freak or subscriber to the Antaeus myth. And I found your model of the swing to be based on sound physics. So ground force "generation" is a misleading term. And I suspect you're right that the feeling of being grounded is more an effect of other good movements and not a cause. Yet if you can get to that effect more easily by "thinking" (I guess the word, "believing" would be more accurate) it to be a cause, it would still work.
But what bothers me here is that thinking something false would work better than knowing what is true. So let me just ask you, what's the practical take away of what we should be aware of in the swing from the realization that the ground isn't generating force? Thanks for the patience.
mandrin
New
cnadon,
Excellent questions.
With regard to ground forces simply concentrate on your swing and let ground forces do their usual thing without much supervision.
In general any belief, right or wrong, is fine as long as it does not cause to discourage or prevent someone to use proper technique.
The placebo effect is an excellent example the importance of imagination over physical reality. Sometimes even more powerful than the real medication.
Likewise many golfers cultivate sensations, feelings, ideas, which are not really of the domain of reality but help them greatly in their game.
I simply believe that golf is still primarily an art and only partly science. But gently cleaning up scientific misconceptions can't hurt in the long run.
Dariusz J.
New member
Well, it would depend on how much a given motion is being dependent on horizontal forces. Take e.g. post-secret Hogan into account - he was so much aware about how to benefit from horizontal ground forces and torques (being somehow a small and light person) that he felt he needed an additional spike under his rear foot sole, which was enough fot the vast majority of scenarios. However, as we remembered, he lost his 5th US Open because his rear foot slipped in muddy ground of the 18th tee at Olympic.
Great posts, Mandrin.
Cheers
James Marshall (Hogan1953)
New member
Mandrin,
Going back to my original question, would it be fair to say therefore that ineffective downward vertical forces in the transition compromise the generation of force/energy in the horizontal axis?
As regards technique, would a thoracic spine tilting slightly targetward in the transition facilitate keeping the lead shoulder low thus increasing the ability to exert more force downward?
Thanks,
James
Going back to my original question, would it be fair to say therefore that ineffective downward vertical forces in the transition compromise the generation of force/energy in the horizontal axis?
As regards technique, would a thoracic spine tilting slightly targetward in the transition facilitate keeping the lead shoulder low thus increasing the ability to exert more force downward?
Thanks,
James
mandrin
New
Dariusz,
Thanks for the compliment.
There is no special wisdom manifested by Hogan using an extra spike. Just smart common sense. One slips, so increase friction.
Some in golf make too much a deal of ground forces, probably motivated to find yet anther niche to sell goods and services.
I like the anecdote about Sam Snead, practicing bare feet. Augmenting awareness of the ground feet interaction to help fine tuning the quality of his swing.
Any normal person knows instinctively how to deal with ground forces. Just watch a person dealing with his locomotion on a slippery surface.
If you make such a person a complement about how deftly he utilizes ground forces he will most likely look at you with genuine bewilderment.
Dariusz J.
New member
I agree. However, Hogan was wise enough not to give up his swing principles because he was afraid of his rear foot slipping out due to excessive torques in the lower leg areas - instead, he thought how to increase the friction coefficient and found a solution.
Yep, I like the anecdote, too. I read somewhere that he wanted to play barefooted at Augusta during Masters but he was not allowed to...
The truth is that Snead's swing was primarily based on vertical forces, much less on horizontally oriented ones as e.g. Hogan's. I doubt that Hogan could swing barefooted...
Cheers
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mandrin
New
James,
The problem with golf is that it is so difficult to approach scientifically. Models are fine as they isolate certain parameters. But once you look at individual golfers in detail scientifically they are wildly different notwithstanding very similar visual similarities. Ground reaction forces generated by golfers are likely a very, very individual trait to each golfer. Just a few elements. Static weight distribution, dynamic 3d weight shift in back swing. Where is weight at transition. First move down, lateral, down, rotational? I am fairly sure that golf researchers using forces plates occasionally pull on their hair in despair trying to find some lead in the bewildering complicated signal traces measuring 3d forces and torques.
'Going back to my original question, would it be fair to say therefore that ineffective downward vertical forces in the transition compromise the generation of force/energy in the horizontal axis?'
Hogan, how do you generate downward force in the transition? There is the given gravitational downward pulling force and you can distribute that between your two feet. Moreover you can by motion of body parts increase or decrease dynamically your apparent weight.
'As regards technique, would a thoracic spine tilting slightly targetward in the transition facilitate keeping the lead shoulder low thus increasing the ability to exert more force downward?'
It is very difficult to answer your question in isolation. For instance are you trying to keep most of the weight initially on the trail foot or rather on the front feet as the active pivot in the down swing. Or keeping a more centered action with both sides active simultaneously.
A golf swing is a holistic event and it takes quite some experience to be able to sense through the apparent swing motion and get a handle on the internal guts and invisible exertions of any golf swing.
??
Should we be asking questions about the statement, "Some brisk upward motion will increase dynamic weight and hence friction forces, if so desired?"
Should we be asking questions about the statement, "Some brisk upward motion will increase dynamic weight and hence friction forces, if so desired?"
cnadon,
I sympathize as frequently ground forces are dealt with in a very vague and purely intuitive way. I am not aware of anyone analyzing ground forces as I have done. Hence it takes a bit of exposure before a very different way of looking at this matter seems to make sense.
I kind of feel in your questions the frequent vague notion of some ground force into which one can tap to increase power in the golf swing. It is kind of suggested by golf instruction when claiming having a method to efficiently exploit ground forces.
This however is approaching the golf swing in a tipsy topsy way. Ground forces do not have an existence independent of a golfer but are rather generated by the golfer himself. A weak swing generates weak ground forces and a power full swing strong ground forces.
Basically the input power comes from the torque, caused by the shear forces between feet and earth. But simultaneously the normal forces between feet and earth should generate enough friction to prevent slip. Some brisk upward motion will increase dynamic weight and hence friction forces, if so desired.
Perhaps not very exiting but there is no esoteric method to suck mystique power from the earth. The feel of "effortlessness" from a well grounded swing, you refer to, is due to hard work having resulted in proper technique. Mother earth is perhaps generous but does not know much about golf.
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Jon Hardesty
New
I think the brisk upward motion increases the normal force of foot contact, thus allowing more shear force to be applied without slipping.
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