I'm science based. I go by numbers (data). I refer you to figure 7 or linked pdf (above) there is you angular velocity for 4 different golfers. Its increasing (at slightly varying rates) for all golfers. Its not constant and there for the concept of COAM does not apply.
Help me try to understand where you're coming from. What is it about rejecting the COAM myth that troubles you? For instance is it because you've come to believe COAM is responsible for the release? Just asking.
C
no nmgolfer im interested in delayed hip action..for e.g move the center of mass to the left earlier while the shoulders/arms/hands are still loading . So they move forward on an angle..bit of a lull..and then boom
OK... I'm with you now... I'll attempt an answer before I leave...
Basically I agree with Bio's mentor (Welch), i.e. the brains in that operation. Wether walking or golfing we create "motion" by shifting our CG thereby creating a temporary imbalance. In the golf swing we "fall" (and catch ourselves). Where I differ with Welch's concept its the notion that that its the shear force reaction at the feet that is what's most important. That concerns motion in the horizontal plane but it neglects the larger motion in the vertical (yes I know horz. and vertical are not the "correct" terms here). Bottomline is all golfers are (falling) in some combination of horz AND vert.
Just a suggestion... If yYou want to improve your golf swing, take the spikes off your shoes and go practice hitting off loose dirt (using a tee) where your feet will slip if you apply too much shear force. It will teach you to "fall" in the vertical plane. IMOP that's key.. that's where the "power" is at.
Take a look at young Mike Austin. http://www.mikeaustingolf.com/video/early_lessons.wmv He's falling around a posted left leg. Centripetal acceleration keeps him rotating about his posted left leg the same way it keeps the moon rotating about earth. He's falling in the vertical (not horizontal) plane. Even still, angular momentum is changing ... its not being conserved.
I leave you with this: COAM and Kinetic Chain Momentum transfer is BS. Hand path and learning to fall correctly are key and always Swing easy hit hard.
no_mind
Originally Posted by pistol
no nmgolfer im interested in delayed hip action..for e.g move the center of mass to the left earlier while the shoulders/arms/hands are still loading . So they move forward on an angle..bit of a lull..and then boom
No mind golfer,
depends how you take an insult, in australia we call this Sh''t stirring, stirring your mates up and getting a reaction, it's all fun and games.
I never take what you say personally, I laugh at your insults.
If you agree with shear forces , then your admitting your agreeing with conservation of monentum, and coam.
how you think normal and shear forces work, conservation momentum.
"agree with shear forces"????? What kind of ridiculous idiocy is that? Its like saying you agree the sky is blue....
Admit it Bio-BSer, you're a technician whose been taught how to perform a measurement, but you're clueless when it comes to interpretation of results.
Its obvious y what you've written (here and elsewhere) that you have no clue what shear force is let alone a dof or COAM. And the fact that you are such fawning sycophant of homer's proves that you are completely unaware how riddled with technical error his work really is.
But what's worst is that think the spine is designed for twisting and or that there is ANY power to be had by torquing the torso. That is down right scary. Mark my words you will be sued for injuries you will cause.
Lasty you may think being an a-hole is all "just fun and games" but where I'm from its just BEING AND A-HOLE.
Originally Posted by biomechanic
No mind golfer,
depends how you take an insult, in australia we call this Sh''t stirring, stirring your mates up and getting a reaction, it's all fun and games.
I never take what you say personally, I laugh at your insults.
If you agree with shear forces , then your admitting your agreeing with conservation of monentum, and coam.
how you think normal and shear forces work, conservation momentum.
"agree with shear forces"????? What kind of ridiculous idiocy is that? Its like saying you agree the sky is blue....
Admit it Bio-BSer, you're a technician whose been taught how to perform a measurement, but you're clueless when it comes to interpretation of results.
Its obvious y what you've written (here and elsewhere) that you have no clue what shear force is let alone a dof or COAM. And the fact that you are such fawning sycophant of homer's proves that you are completely unaware how riddled with technical error his work really is.
But what's worst is that think the spine is designed for twisting and or that there is ANY power to be had by torquing the torso. That is down right scary. Mark my words you will be sued for injuries you will cause.
Lasty you may think being an a-hole is all "just fun and games" but where I'm from its just BEING AND A-HOLE.
Who mention twisting and torquing the body, sued for teaching people not to over twist and torquing their body be my quest to sue.
People develop the wrong perceptions of body rotations from glossy magazines. what the x factor thats destroyed more swings and injured more people, I agree go sue the x factor boys.
welldone to your letter from your biomechanists friend, he's right, it's called muscular loading, go to see he is on the right path. I sincerely mean this well done to him, he is on the money. I agree with him.
the chain is an indication to what the body is doing in a motion, all it indicates is rotational speeds, show's each segments acceleration and deceleration and if the segment are moving in the right sequence and whether the body segment is efficient and inefficient in their swing.
there is stability as well,muscular loading and club dynamics as well to consider, which we measure.
measuring shear force is also some thing we measure, we can tell you if they apply enough shear force or not enough.
No-mind golfer you may not agree on coam that's ok, but if we were to speak in person you would find we are on the same page on a lot of things.I like the letter you presented and liked what was said.
I would love to explain coam, but to put to paper is to hard to explain.
honestly send me a email and would love to organise a webinar and speak with you further. i would be happy to show you in depth what we do. how this is measured and why would you like to find out?
I thought that this thread was removed from the forum. I didn't realize that is was moved to this section.
Wow! It is good to see nmgolfer's posts again. I thought that he had disappeared from online golf forums. I especially like his sound argument that the logic of a poster's argumentative position depends on its intrinsic logicality (its intellectual coherence and its concordance with objective reality) and not on the "qualifications" of the poster.
I am not surprised that he found Biomechanic's posts of little value, and I am not surprised that Biomechanic thought he was a Jeff-clone.
Going back to the "facts" regarding the kinetic chain - I agree with nmgolfer that the kinetic chain and COAM doesn't apply to torso movements in a golf swing. However, I think that nmgolfer is wrong about two points.
1)I think that COAM does apply to the relationship between the movement of the left arm and the clubshaft.
2) I think that the the left arm slows down prior to impact.
nmgolfer only quoted one source that claims that the arms/hands do not slow down prior to impact - Nesbit's research study. However, there is substantial evidence from many other sources that demonstrate that the left arm/hands do slow down prior to impact.
An explanation of why the hands should be expected to slow down prior to impact comes from an understanding of TGM mechanics. Here is my personal explanation.
In a pivot-driven swinger's action, the pivot supplies swing power that is responsible for the release of PA#4. From then on, the body pivot motion does not affect power production because the PA release sequence is 4:2:3 and PA#2/3 are passive release phenomena. The club is an inert object that doesn't know from where the source of power is derived - it only responds to the pull force at the grip (exerted by the left hand). In that sense, the double pendulum swing model applies. The clubshaft is equivalent to the peripheral arm and only responds to pull forces exerted at the peripheral hinge joint (left hand), and the peripheral hinge joint only moves as fast as the central arm (equivalent to the golfer's left arm).
In a pivot-driven swing, the pivot supplies swing power that causes the release of PA#4. Once PA#4 has been released, then no more energy is imparted to the system of the flying left arm (from the central torque generator = body pivot motion) . In that sense the flying left arm is a motional system containing a "fixed" amount of energy. When PA#2 releases, and the clubshaft becomes more in line with the left arm, then the left arm must slow down. There are two valid explanations for this phenomenon. The one explanation relates to COAM.
Explanation number 1
If the left arm (central arm)/clubshaft (peripheral arm) is a system in motion, and there is a "fixed" amount of energy in the entire motional system, then the central arm must slow down if the peripheral arm speeds up - because energy moves from the center to the periphery.
Explanation number 2
Another way of understanding this COAM phenomenon relates to the distribution of the COG relative to the axis of rotation. If the COG of the entire motional system moves further from the central axis of rotation (which is the central hinge point from which the central arm is suspended in a double pendulum model), then the entire motional system must slow down. That's the explanation evoked by David Tutelman in his explanation.
I now believe that the hands slow down prior to impact (because the left arm slows down prior to impact) in an excellent golfer's swing and it's a good thing - because it allows time for release of PA#3 and the squaring-up of the clubface prior to impact.
Here is a capture image of Tiger Woods swing - videod at 4,000 frames/second. Every white dot joining those red lines represents 10 frames (1/400th second) and one can see that Tiger's left arm slows down just before impact.
There is one other unquantifiable factor that makes my COAM explanation far from full-proof.
The COAM idea is based on the belief that all the energy propelling the clubshaft is only passively derived from the left arm (according to the principle of COAM), and that the left arm derives all its energy via the release of PA#4. However, one needs to consider another factor - the role of left forearm muscles in actively releasing PA#2 and/or PA#3. If the left forearm muscles supply any energy to actively release PA#2 or PA#3, then the left arm may not need to slow down as much as predicted by the COAM theory.
OK... I'm with you now... I'll attempt an answer before I leave...
Basically I agree with Bio's mentor (Welch), i.e. the brains in that operation. Wether walking or golfing we create "motion" by shifting our CG thereby creating a temporary imbalance. In the golf swing we "fall" (and catch ourselves). Where I differ with Welch's concept its the notion that that its the shear force reaction at the feet that is what's most important. That concerns motion in the horizontal plane but it neglects the larger motion in the vertical (yes I know horz. and vertical are not the "correct" terms here). Bottomline is all golfers are (falling) in some combination of horz AND vert.
Just a suggestion... If yYou want to improve your golf swing, take the spikes off your shoes and go practice hitting off loose dirt (using a tee) where your feet will slip if you apply too much shear force. It will teach you to "fall" in the vertical plane. IMOP that's key.. that's where the "power" is at.
Take a look at young Mike Austin. http://www.mikeaustingolf.com/video/early_lessons.wmv He's falling around a posted left leg. Centripetal acceleration keeps him rotating about his posted left leg the same way it keeps the moon rotating about earth. He's falling in the vertical (not horizontal) plane. Even still, angular momentum is changing ... its not being conserved.
I leave you with this: COAM and Kinetic Chain Momentum transfer is BS. Hand path and learning to fall correctly are key and always Swing easy hit hard.
no_mind
Hey NM, I think you are the guy who told someone on another forum not to lie about moving objects on car dashboards to an English major golf pro who was obviously quite confused and leery about the professional advice and information to "use your pivot to snap your Kinetic Chain, and to assist your arms, hands, and club with creating the proper D plane for the selected shot. Everything else is show biz." They deleted all your posts and maybe some other poster's posts as well, so I'm not sure it was you. Thanks for sticking up for me if it was indeed you.
Anyway, my posts to that site haven't been deleted and since the time you were wiped out, I've continued to post there to implore anyone to explain to me in the Queen's English what the hell a "kinetic chain snap" is and how you can use your "pivot" to do it. Well I haven't gotten any good answers except that I am wrong to even cast a doubt in the direction of pivot induced kinetic chain snapping since some PHD clearly posted and explained a diagram of 16 or 8 piece linked chains to show that kinetic chain snapping is not only possible but likely necessary to generate the adequate or "missing?" horsepower that Cochran and Stobbs struggled to substantiate in order for good golfers to hit balls as far as they do..
I have been studying biomechanical research concerning the golfswing for many years and I've yet to uncover solid evidence to support the idea that power in good golf swings is generated by rotational movements of the pelvis and spine. Of course these rotations are necessary to create good backswings, good transitions, and good downswing posturings to strike the ball well, but I've never heard of these rotations (especially hip/pelvic rotations) as being able to generate or store significant power for golf. In fact I'm struggling to find any credible biomechanical literature wherein twisting, or coiling, or winding up, or pivoting of the pelvis and torso are used to describe dominant power generation in any powerful forms of human locomotion.
The credible research that I have studied strongly suggests that the difficult to describe lateral slide and resultant weight pressure shift and slight pivot of the hip girdle toward the target and onto the left leg is responsible for generating the real power for good golf swings. The research always describes this lateral pelvic shift/slight rotation as occurring BEFORE the completion of the backswing, and the research generally claims that this movement serves two critical functions in good golf swings: First, it is opposed by the grounded left foot and this opposition promotes subsequent rotation of the pelvis to the left about and above the left femoral head, which allows the pelvic girdle to rotate and face the target by the end of the swing. Second, it serves to pre-stretch principle upper extremity adductors (primarily pectoralis major and latissimus dorsi) before golfers initiate the downswing by contracting those muscles. More recent research shows that this PRE-DOWNSWING lateral weight pressure shift and slight leftward rotation of the pelvic girdle likely pre-stretches the right external oblique muscle as well, which will subsequently contract and initiate torso rotation to the left side on the downswing. It is the stretching and subsequent contraction of these muscles that enhance or harness the power created by the initial PRE-DOWNSWING lateral shift and slight rotation of the pelvis. I'd like to throw in that I hope most golfers have effectively hinged their right forearm about its elbow and both hands about their wrists, thus pre-stretching the right triceps and both sets of appropriate forearm muscles to contract on the downswing to further and dramatically enhance or harness the power generated by the initial PRE-DOWNSWING lateral shift and slight rotation of the pelvis.
I interpret from your posts that you basically espouse the validity of the research that I have studied. None of this research describes COAM or pivot induced kinetic chain snapping as enhancing, harnessing or "overpowering?" power generation. Golfswings are kinetic chains but "kinetic chains" are merely descriptions of types of movement and/or sequencing of movements within a given activity. I don't think "kinetic chains" describe power generation or power enhancement.
I think a lot of good people have been convinced that the lateral pelvic shift/rotation thing STARTS the downswing instead of PRECEDES it. If measurements are taken of a PRECEDING THE DOWNSWING MOTION as being a START OF THE DOWNSWING motion, then those measurements will likely be compared to a backswing that hasn't ended yet - and huge brain snaps will occur in the wrong direction as a result.
By the way, Tiger is the best at slowing and stopping his pivot and arms after he starts the downswing, especially when he hears a camera click, but alas, the club never hits the ball because it stopped too!
NM, thanks for sticking to your guns. I don't want to write any more posts for a long time. If anyone can be right concerning this subject, I firmly believe that it is you. Don't let it go to your head though!
I have been studying biomechanical research concerning the golfswing for many years and I've yet to uncover solid evidence to support the idea that power in good golf swings is generated by rotational movements of the pelvis and spine. Of course these rotations are necessary to create good backswings, good transitions, and good downswing posturings to strike the ball well, but I've never heard of these rotations (especially hip/pelvic rotations) as being able to generate or store significant power for golf. In fact I'm struggling to find any credible biomechanical literature wherein twisting, or coiling, or winding up, or pivoting of the pelvis and torso are used to describe dominant power generation in any powerful forms of human locomotion.
Really good stuff, coophitter. Thank you for another great post.
From a little something I wrote based on an article my chiropractor gave me a about spinal injury due to rotation.
"The Golfing Machine by Homer Kelley teaches that there are four sources of power in the golf swing, known as Power Accumulators- or Power Sources- none of which are based on torso rotation.
The turning of the body, "pivot", should be a reaction to where the hands need to go. This is referred to as a "hand controlled pivot" in The Golfing Machine. Many teachers believe that the rotation of the body controls the hands. This is fine if you want to hit less than your maximum distance potential and create room for injury.
The geometry and physics of the golf swing, studied by all Authorized Instructors of The Golfing Machine, dictates that the hands always have a destination. Give your hands an assignment, where to go and what to do, then have them complete that assignment. The body should play a supporting role, and not vice-versa."
__________________ Hitting the Ball is the easiest part of the game-hitting it effectively is the most difficult. Why trust instinct when there is a science."1-G.
From a little something I wrote based on an article my chiropractor gave me a about spinal injury due to rotation.
"The Golfing Machine by Homer Kelley teaches that there are four sources of power in the golf swing, known as Power Accumulators- or Power Sources- none of which are based on torso rotation.
The turning of the body, "pivot", should be a reaction to where the hands need to go. This is referred to as a "hand controlled pivot" in The Golfing Machine. Many teachers believe that the rotation of the body controls the hands. This is fine if you want to hit less than your maximum distance potential and create room for injury.
The geometry and physics of the golf swing, studied by all Authorized Instructors of The Golfing Machine, dictates that the hands always have a destination. Give your hands an assignment, where to go and what to do, then have them complete that assignment. The body should play a supporting role, and not vice-versa."
What measured data does the chiropractor have to support his beliefs.
I'm T.G.M all they way I love homers work, the day I was introduced to golf I was taught educated hands, but my weakness was human body motion.
My body didn't fire in the right sequence in order for the mechanics to be executed correctly, I can shot par on my ear. what let me down is not being able to 4 rounds of 68 on my ear. This was due to incorrect human body motion.
We need the world of mechanics and I'm so happy we have yoda , mike and have homer who gives us understanding of mechanics.
This is the world of mechanics and there is another world human body motion,
how can mechanics be executed correctly when human body motion isn't performing they way it should in order for mechanics work.
Homer states 6-M-1 that is the downswing sequence.
you can have the best educated hands on the planet but with out the human body motion , moving in the correct sequence educated hands will never happen.
In every all bat and ball sports, throwing a ball is the same sequence in kinetic linking.
This isn't from he said , she said, a form of opinions, this is developed from measured science.
Bear in mind you talking about mechanics a different world to human body motion.
My question is I don't question homers work he's on the money. But I question how people deliver what he's says and if they truly understand his work.
They may understand the mechanics but how well do they understand the human body motion in order to work.
Why hasn't there been a world number 1 golfer who's T.G.M student, why isn't T.G.M students dominating golf on tour ?
I believe it's the communication of homers work. And lack of knowledge how human body motion functions.
Video can't measure human body motion, nor can ball flight. I think we all need to get realistic, We need homer, we also need human body motion.
Last edited by biomechanic : 11-04-2008 at 03:03 AM.
I sincerely mean this well done to him, he is on the money. I agree with him.
B. J. Hathaway, G.S.E.B., M.C.I.
Hybrid Mode
