GMcG,
doesn't the above calculation make the assumption that all the difference in KE from 100 to 150 mph is transferred to the ball?...i don't think a 150 mph impact speed clubhead slows to 100 mph during impact...anyway, as i've said before i think it is the equation F=ma that answers the distance question and not velocity but acceleration at impact that makes the most difference (assuming equal clubs and equally good ball contact) and that is why slow easy swings with late release and therefore high late acceleration can hit the ball as far or farther than some really hard swings.
-hcw
Hcw,
Calculation used to determine the relative amounts of energy required by the Golfing Machine to reach various velocities – not modeling around impact.
Other matters you allude to such as seemingly slow swingers out hitting those moving faster are cases of efficient transfer of power producing late clubhead speed. This is a matter of technique.
The source of my study on clubhead speed and power comes from Mark Evershed's book....The Golf Solution....
Here is an excerpt from that study....
If you still believe that the body creates the speed and power in your golf swing, and pervious pages have not yet changed your mind, You can stilll prove it to yourself by following the directions below. You will need a device to measure your clubhead speed.
S1 After warming up, measure the clubhead speed of your driver using your normal swing and averaging the three highest readings. This figure respresents 100% of your speed and energy potential.
S2 With your feet together, swing and measure your clubhead speed. (This eliminates the contribution of the body).
S3 From your knees, swing your driver and again measure your clubhead speed (This eliminates the body and the sequence (vertical drop).
S4 Finally, while still on your knees, swing the club with your hands, wrists, and forearms stiff or immobilized. The clubshaft should point at the middle of your chest during the entire swing. (This eliminates the body, vertical drop and hands, and measures only the contribution of the arm swing).
Here are Mark Eversheds results....someone who is accomplished golfer....
Quiet Body Clubhead velocity Contribution 4.6%
Clubhead Power Contribution 8.9%
Educated Hands Clubhead velocity Contribution 60.0%
Clubhead Power Contribution 58.9%
On-Plane Arms Clubhead velocity Contribution 19.1%
Clubhead Power Contribution 3.6%
The above exercise is in Mark's book....if you do the above procedures and send in your inputs Mark will mail back your results...
Mark's golf swing is based on an arm swing (right arm swing)....
The vertical drop term means, the start of the swing is a dropping action of the arms....
Quiet Body term means....the body is responding to the action of the swinging hands and arms.....the right forearm is supplying the arm acceleration.
DG
DG,
This doesn't seem terribly scientific or reasonable. For instance it may be that S2 tests a player’s balance or the contribution of lateral movement in the swing but eliminates the contribution of the body? Nope.
1. I don't subscribe to JK. Have read only a little of his stuff and ......
2. You seem to rely on Jorgenson
Quote:
Jorgenson in "The Physics of Golf" determines that only the legs contain enough muscle mass to power the golf swing.
Interesting to note Jorgenson did a paper exercise to come up with most of his conclusions. Actually regarding the power, he used the formula and applied it to the golf swing. Based on a professional golfer generates 2 hp (not sure where this number came from) he deduced that it require 32 pounds of muscles or 1/8 horsepower per pound and muscles must be used in pair, so 32 lbs. Since the arms and shoulders don't have 32 lbs he reasoned that other muscles must be used. Those were the legs, buttock, back aand abdomen. He considered these to be the lower body muscle group.
The hips are key to momentum transfer. If hip action is initiated it is with the buttock's muscles. The leg muscles (hamstrings) can push and pull the hips.
I find that in the introduction by Jorgenson, his description of Chapter 3, "... explains how the golf swing compares to theaction of a bullwhip, how the large muscles of the lower body, although they are not connected to the arms are used to enhance the speed of the golf club, how the pull of the shoulder on the arm works in the golf swing and who we find that the golfer does not swing about a quiet center in the downswing."
I find his choice of words, 'enhance' to support the position I have held and what I have said. I stated earlier that the lower body 'amplifies' allowing greater power.
As for the hip movement, I subscribe to this being either the first action in the down stroke, or as the golfer is about to complete the back stroke (for those who want a reference 12-3-0 section 6 #24).
Martee,
I have read Jorgenson and am glad that you have as well. I do not consider Jorgenson to be a definitive work (science does not stand still) and even within the quotes you have provided there is an error that I will show you that is pertinent to the discussion.
Now let’s be clear about what we are talking about. We are talking about which muscles perform the work (physics sense) that causes the rotor of 7-12 to spin and drive the Golfer’s Flail.
Choices are:
Leg muscles that drive hip rotation.
Torso muscles that drive torso rotation relative to the hips.
Care to add any??
If you still believe that the body creates the speed and power in your golf swing, and pervious pages have not yet changed your mind, You can stilll prove it to yourself by following the directions below. You will need a device to measure your clubhead speed.
S1 After warming up, measure the clubhead speed of your driver using your normal swing and averaging the three highest readings. This figure respresents 100% of your speed and energy potential.
S2 With your feet together, swing and measure your clubhead speed. (This eliminates the contribution of the body).
S3 From your knees, swing your driver and again measure your clubhead speed (This eliminates the body and the sequence (vertical drop).
S4 Finally, while still on your knees, swing the club with your hands, wrists, and forearms stiff or immobilized. The clubshaft should point at the middle of your chest during the entire swing. (This eliminates the body, vertical drop and hands, and measures only the contribution of the arm swing).
dg,
well this probalby illuminates why we were on different sides of this issue...i disagree that the above exercises eliminate the body components as listed...in all of these your hips are still moving and this is powered by muscles in you legs...S2 and S3 maybe eliminate some hip turn velocity b/c of decreased balance ( for S3 depending on how far apart your knees are), but especially problematic is S4 which i think does pretty much the opposite of what's stated as far as the body element goes...if your arms are fully extended and immoblized then none of the arm muscles including the trail tricep do anything...what is moving the whole assembly are you hips via you leg muscles and maybe some torso muscles, you have really eliminated everything BUT the body/hips/legs!
Calculation used to determine the relative amounts of energy required by the Golfing Machine to reach various velocities – not modeling around impact.
Other matters you allude to such as seemingly slow swingers out hitting those moving faster are cases of efficient transfer of power producing late clubhead speed. This is a matter of technique.
Golfie
GMcG,
fair enough on the first point and totally agree on the second...however, i think the problem is that so much focus is often put on the parameter of clubhead velocity that it becomes the ultimate goal and obscures the more important technique of "efficient transfer of power" which i call "maximizing acceleration" at impact...well at least that's what happened to me, i think ...luckily, that is slowly but surely being corrected!
1. I don't subscribe to JK. Have read only a little of his stuff and ......
2. You seem to rely on Jorgenson
Quote:
Jorgenson in "The Physics of Golf" determines that only the legs contain enough muscle mass to power the golf swing.
Interesting to note Jorgenson did a paper exercise to come up with most of his conclusions. Actually regarding the power, he used the formula and applied it to the golf swing. Based on a professional golfer generates 2 hp (not sure where this number came from) he deduced that it require 32 pounds of muscles or 1/8 horsepower per pound and muscles must be used in pair, so 32 lbs. Since the arms and shoulders don't have 32 lbs he reasoned that other muscles must be used. Those were the legs, buttock, back aand abdomen. He considered these to be the lower body muscle group.
The hips are key to momentum transfer. If hip action is initiated it is with the buttock's muscles. The leg muscles (hamstrings) can push and pull the hips.
I find that in the introduction by Jorgenson, his description of Chapter 3, "... explains how the golf swing compares to theaction of a bullwhip, how the large muscles of the lower body, although they are not connected to the arms are used to enhance the speed of the golf club, how the pull of the shoulder on the arm works in the golf swing and who we find that the golfer does not swing about a quiet center in the downswing."
I find his choice of words, 'enhance' to support the position I have held and what I have said. I stated earlier that the lower body 'amplifies' allowing greater power.
As for the hip movement, I subscribe to this being either the first action in the down stroke, or as the golfer is about to complete the back stroke (for those who want a reference 12-3-0 section 6 #24).
Martee,
I have read Jorgenson and am glad that you have as well. I do not consider Jorgenson to be a definitive work (science does not stand still) and even within the quotes you have provided there is an error that I will show you that is pertinent to the discussion.
Now let’s be clear about what we are talking about. We are talking about which muscles perform the work (physics sense) that causes the rotor of 7-12 to spin and drive the Golfer’s Flail.
Choices are:
Leg muscles that drive hip rotation.
Torso muscles that drive torso rotation relative to the hips.
Care to add any??
Can we at least agree on the topic and choices?
Golfie
I am not sure where this is going, what you are trying to prove but the original discussion has long since been left behind and you continue to reframe the questions.
I also don't know where I incorrectly posted a quote, unless it was a spelling error, what did I quote wrong?
As for last suggestion, I can only conclude I am either not making myself clear or you are not reading what I have wrote.
Obviously we are having a failure to commincate.
I would be interested in seeing your references to back your position, cause I think it is clear Jorgenson doesn't but does support my position.
As for work, that was not what we were discussing.
As for the most powerful swing, if a golfer didn't use his entire body and longest club he would be a fool.
1. I don't subscribe to JK. Have read only a little of his stuff and ......
2. You seem to rely on Jorgenson
Quote:
Jorgenson in "The Physics of Golf" determines that only the legs contain enough muscle mass to power the golf swing.
Interesting to note Jorgenson did a paper exercise to come up with most of his conclusions. Actually regarding the power, he used the formula and applied it to the golf swing. Based on a professional golfer generates 2 hp (not sure where this number came from) he deduced that it require 32 pounds of muscles or 1/8 horsepower per pound and muscles must be used in pair, so 32 lbs. Since the arms and shoulders don't have 32 lbs he reasoned that other muscles must be used. Those were the legs, buttock, back aand abdomen. He considered these to be the lower body muscle group.
The hips are key to momentum transfer. If hip action is initiated it is with the buttock's muscles. The leg muscles (hamstrings) can push and pull the hips.
I find that in the introduction by Jorgenson, his description of Chapter 3, "... explains how the golf swing compares to theaction of a bullwhip, how the large muscles of the lower body, although they are not connected to the arms are used to enhance the speed of the golf club, how the pull of the shoulder on the arm works in the golf swing and who we find that the golfer does not swing about a quiet center in the downswing."
I find his choice of words, 'enhance' to support the position I have held and what I have said. I stated earlier that the lower body 'amplifies' allowing greater power.
As for the hip movement, I subscribe to this being either the first action in the down stroke, or as the golfer is about to complete the back stroke (for those who want a reference 12-3-0 section 6 #24).
Martee,
I have read Jorgenson and am glad that you have as well. I do not consider Jorgenson to be a definitive work (science does not stand still) and even within the quotes you have provided there is an error that I will show you that is pertinent to the discussion.
Now let’s be clear about what we are talking about. We are talking about which muscles perform the work (physics sense) that causes the rotor of 7-12 to spin and drive the Golfer’s Flail.
Choices are:
Leg muscles that drive hip rotation.
Torso muscles that drive torso rotation relative to the hips.
Care to add any??
Can we at least agree on the topic and choices?
Golfie
I am not sure where this is going, what you are trying to prove but the original discussion has long since been left behind and you continue to reframe the questions.
I also don't know where I incorrectly posted a quote, unless it was a spelling error, what did I quote wrong?
As for last suggestion, I can only conclude I am either not making myself clear or you are not reading what I have wrote.
Obviously we are having a failure to commincate.
I would be interested in seeing your references to back your position, cause I think it is clear Jorgenson doesn't but does support my position.
As for work, that was not what we were discussing.
As for the most powerful swing, if a golfer didn't use his entire body and longest club he would be a fool.
Martee,
I will post, in the next couple of days, a whole treatise on which muscles are useful for powering the golfer's flail. As to not responding to your comments specifcally there are many particular comments I could have made along the way but was hoping not to have to overeducate. It appears that more of a treatise approach may be more benfieical for anyone who still cares as the post-response dialogue inevitably leads to wiggling, misunderstandings due lack of common base, talking at cross-purposes, and sidetracking. I now more appreciate why Yoda goes to such lengths to compose comprehensive responses to significant rather tyahn trying to go along step by step.
Until then enough for now.
Golfie
P.S. It was not your mistake but Jorgenson's for listing incompatible muscle groups in his search muscle mass.
I believe that one's PERCEPTION of WHAT is POWERING a golf stroke may be, and often is different than what actually is the case, in the most efficient and powerful strokes. One may FEEL the whole thing with their HANDS, but we know there is much more going on. One may FEEL SOMETHING within ZONE 1, but that does not negate the contributions of ZONE 2, AND 3, whether the golfer is aware of them or not.
PIVOT LAG(6-C-O) is in there in the most efficient and powerful strokes. Try to stand on ice and strike a ball... you will see!!
...luckily, that is slowly but surely being corrected!
Linear Mode
