Those are great pics Two…
thanks for sharing…
Sure, the hands to slow in their tangential travel, but what we don’t see is the pick up speed of their uncock and rotation, or what we do in our module #1 work. The hands can actually become more active in a rotational way, even though they do slow down in the tangential arc of their travel…
Nothing wrong with understanding this stuff…
twomasters,
Indeed, Joe Dante’s book, – ‘FOUR MAGIC MOVES To Winning Golf’ - is way ahead of its time, with a serious effort to try introduce science into golf instruction. However the explanations of the down swing given in chapter 7 using COAM are erroneous for the reasons spelled out in the opening post.
It has become with time normal in golf instruction books /articles to state that COAM rules the down swing without any second thought. It is certainly a good thing to try to explain golf using science, but science is not some flexible matter pliable in any direction. It has its rules and definitions which are rather strict.
The correct scientific approach to explaining the possible slowing down of the hands resides in the consideration of the interaction of linked masses, the kinetic chain action - a typical multibody dynamics problem. Even considering the very simple double pendulum swing, such as is the case for an Iron Byron, it is way more complex than most would suspect.
However, not easy, but by properly applying a torque, starting somewhat modestly and peaking sharply close to and through impact one does not necessarily have this slowing down of the hands during impact, even creating possibly some positive acceleration. COAM adepts would be completely mystified with such a swing, not knowing where to go with their theory. 
That was a lightbulb…“but what we don’t see is the pick up speed of their uncock and rotation”…
Once again, I’ve been looking at these pictures for years and never saw /considered what you said here. Thanks!
I have never seen Iron Byron, in person. Does where “his” lever attaches to the club rotate and uncock like the wrists?..if not, is this not a serious fallacy or drawback in using him as a model of the golf swing?..aren’t there several other problems…Might be a good thread…“Iron Byron’s deficiencies as a model”
Iron Byron is getting pretty old…looks like someone with engineering and fabrication skills could create something that jives more with reality.
what size feet you got?
I have 10.5 UKs that would love a set of (slightly) used FJ Classics 
twomasters,
COAM - conservation of angular momentum.
Read above slowly and carefully – what does it say?
It does refer to angular momentum being conserved.
What does that mean?
It means having a certain amount of angular momentum to start with and keeping it constant thereafter.
A golfer however is not conserving but instead generating angular momentum.
A golfer starts without any angular momentum whatsoever and is very busy generating angular momentum in the down swing.
Conclusion: COAM does not apply to a golf swing.
The usual examples taken to justify COAM in golf, such as rotating chairs, figure skaters, divers, etc., are indeed all subject to COAM - but a golfer, however, is not !!
To be able to use COAM requires two conditions to be satisfied:
1) a closed system - no external forces.
A golfer does not satisfy neither of these two conditions.
One can twist things any way one chooses it does not change these very simple basic facts.
There is another frequent misuse of COAM. It is usually taken as being at cause for the release. It is not. Forces/torques are at cause not angular momentum.
If I make a fire the close by air molecules start moving frantically around. This is reflected in a higher temperature. It is the fire being cause for the increased molecular motion not the temperature.
Similarly, torques/forces lead to motion which is reflected in an increasing angular momentum. Hence forces/torques are at cause, not the angular momentum, being at effect.
Angular momentum in effect depicts a particular characteristic state of a system, i.e., the motion and the mass distribution of a particular system.
I like to emphasize that ‘conservation of angular momentum’ is one of the most fundamental laws in physics, even more so than Newton’s laws, as it extends equally to, and is valid in, atomic and nuclear physics. It is a scientific law not a golf rule and not flexible in its application.
Whereas the golf swing from start to finish is not a closed system, analyzing the motion muscle fibre by muscle fibre in isolation would indeed show miniature closed systems. A muscle generating motion in some way, momentum carrying that motion through after the muscle has relaxed. Another muscle fibre might be working concurrently or taking over, but COAM does apply to that mini system viewed in isolation. As you say, it’s a fundamental law of physics–it must apply to everything. COAM is existent in the golf swing.
But just the not the way it’s usually tossed around. The example of throwaway in the golf swing leading to poor clubhead speed does have COAM at work on the existing momentum of a member after power has been cut from it, but as we’re adding more power in during our downswing plus the external force of gravity is always present, the biggest principle at play is simple leverage.
Steb,
Let’s imagine that I have you suspended in a harness above the ground. I leave you play as long as you wish with your muscle fibres and miniature closed systems. How does it feel hitting the ball this way with all the COAM at your disposal which you feel is acting from fibre to fibre?
You might also have a look at a previous post on the same subject - Analysis of conservation of angular momentum using model including ground reaction force
I neither said or implied COAM acted fibre to fibre, for that makes zero sense, nor did I say or imply COAM powers the swing, an equally ridiculous concept. Angular momentum does not pass from one ‘thing’ to another, COAM is an inherent principle within the ‘thing’ itself. I know you know this.
Every object in this world that has an angular momentum will obey the principle. If someone wishes to introduce an external force to the object, then that is an additional, associative effect layered on top. The external force will change the angular momentum so overall angular momentum of course will not be conserved, but COAM is still having a component effect on the object’s initial condition momentum.
Is COAM of any relevance to the golf swing? No. Does it exist in the golf swing? yes - it’s exists in anything moving with angular momentum.
Steb,
I might have interpreted what you are saying perhaps not quite the way you intended it. But normally one does not analyze a golf swing thinking in terms of individual muscles fibres. One step further and we are going to be working on a molecular scale.
Hence in your words to avoid any misinterpretation:
“ …nor did I say or imply COAM powers the swing, an equally ridiculous concept. “
“ Is COAM of any relevance to the golf swing? No.”
It seems therefore that we are in total agreement. COAM is neither causal nor relevant in a golf swing.
Hence you therefore also totally disagree with instructors misusing COAM, such as for instance Joe Dante, who considers COAM to be the essence of the golf swing in ’ FOUR MAGIC MOVES To Winning Golf ', since you are convinced that :
it is ridiculous to consider that COAM powers the golf swing, and
COAM has no relevance to the golf swing.
Glad too see someone in total agreement. Very few are going to agree with either you or me.
It is so difficult to let go of this believe in COAM as it seems so natural as explanation and having being repeated so often over the years by so many people.
Mandrin,
What is your point and what has this accomplished… Is this thread really going to help golfers get better…
Who said coam powers the golf swing and who are you referring too…
There are two speeds linear speed and angular speed of the club… If you have deceleration of angular speed you will have poor ball compression…
Not sure who your referring to, who believes coam powers the swing…
One minute you say there is no coam in the golf swing what so ever and then you say there is some coam and has no effect on the golf swing…
What is your point and who really cares… how is this helping people play better golf…
Do you think golfers give a dam about coam … all they care about is what ever works for them so they can play better golf…
How about focusing on something positive for a change and look at how can golfers swing the club move effectively and become more consistent…
Why waste time and energy on this for… what will this achieve … absolutely nothing…
Mandrin,
Can you explain how the figure skater is not working in a closed system with external forces like you suggest…they have skates (golf club) and ice (ground)
looks like the tighter the arms/legs get to the body the faster they can turn
[youtube]http://www.youtube.com/watch?v=NtEnEeEyw_s[/youtube]
Your two numerated points Mandrin are exactly my feelings. And I disagree with instructors like Dante who talk about it in this capacity. Instructors are very quick to grab onto science when it seems to fit their understanding. The problem is that they lose credibility with the people who live and breath science, even though their teaching methodologies might not be based on science and be quite tight.
But I also disagree with instructors who even get science right, for there is simply no need to bring science into it. It’s like they’re cheating, trying to give the student hope because the theory makes sense to the student, so the teachings to follow must be correct. Let the student get hope from results, not understanding theory.
IMO it’s the biggest reason handicaps aren’t improving. Everyone is trying to cheat their way to improvement. The armchair path, and it’s a wild goose chase. Scientists can’t play golf, that’s a fact, so why are instructors giving students scientific awareness? It’s not needed.
Pros play as well as they do because they know bugger all scientifically about their swing. They have no option but to trust the immense power of their subconscious. Our conscious mind is useless learning physical activity, anyone who’s concentrated on learning the moves to a dance knows that. Only when they let go does the dance just mysteriously come and show a semblance of rhythm for the first time. Get a bit of direction and go for it.
I used to like talking science in golf as it combined two passions. And even though I never based my swing on a scientific understanding, with time I found I lost confidence in my subconscious ability to learn. I felt I had to understand something to its minutest detail before I could learn it physically. Now I’m beginning to feel threads like this are now dangerous reads.
Steb, Two…
Ya’ll are right. And I’m guilty. For me, I think it’s a curious nature, and the hope that’ll it’ll help…heck, we’re told that even Hogan would pick the brain of people like Sam Byrd, Mike Austin, etc…so maybe it’s not all bad. But I’m not Hogan…by a long shot. Percy Boomer was a VERY successful teacher( and excellent player)…his book basically totally excludes science and practically only discusses FEELINGS.
When will we ( those like me) learn??
I’m gonna resolve to cutback on the science…and double -up on the time in the basement beating the bag.
biomechanics,
I seem to remember that you did not want to have anything to do with me, never ever. You just could not resist? 
You did not like a feature paper in an important biomechanical conference claiming biomechanics to be immature as science.
Your post, an incoherent rambling, does nothing to restore this very negative image - actually it reinforces it even more.
As soon as you show a more reasonable attitude i.e., making your arguments in a coherent fashion I will be all ears, and only then.
twomasters,
It is only natural for a golfer to firmly believe in COAM. Year in year out there are these images of someone rotating, sitting in a chair, a figure skater spinning or a diver jumping from a board, given seemingly as sufficient evidence that COAM is also ruling the golf swing.
Curiously as long as it is wrong science everybody agrees, how wonderful, how interesting these scientific explanations of the golf swing., etc, etc… However, as soon someone comes around and claims it is all just not true, a sudden and complete turn around, people get upset and start crying out loud that science is useless and of no fxxxxxx use. Rather curious and immature attitude.
This is the same attitude with TGMers in general. Between them they pet each other on the shoulders about being so impressively scientific. Yet, I am barred from LBG before even posting once and being thrown off iseekgolf after only a couple of days. Twomasters, instead of getting emotionally upset, please take it easy. Science is not so much about emotions but about objective truth and facts. So lets look at this in a calm relaxed attitude.
An essential condition for COAM is that there should be no net external torque acting on the system being considered. A chair rotating on smooth bearings, a figure skater during a spin or a jump, a springboard diver during his somersaults/twists have one thing in common - A very small or no external torque acting on them and which can be considered negligible for the very short duration of a somersault, pirouette or twist.
The torque due to friction between skates and ice or that of the bearing friction is negligible, especially for the small time periods considered. The omnipresent gravity force acts through the center of mass of a diver or the figure skater during a jump and hence does not exert any torque. In other words a person in a chair, a figure skater or a diver is, a for a short period of time, virtually isolated from its environment – referred to in science as a ‘closed system’. And COAM definitely applies to these cases.
A golfer however is firmly rooted with his two feet to the earth. Just just ask yourself a simple question – why does a golfer requires spikes on his golf shoes? For what purpose? Simply to be able create the maximum possible torque between him and the ground without falling on his rear end during a golf swing. Obviously this is an external torque and immediately disqualifies the golfer to claim his swing to be governed by COAM.
It is not complicated or esoteric. Angular momentum and COAM have precise definitions and a golf swing simplify does not qualify. Just like in golf, science is played by strict rules and similarly no mulligan is allowed. I do definitely acknowledge that it is all so darned simple, and so cute with COAM, but I am very sorry, it just ain’t true. Instead one needs complicated differential equations to explain. Much less attractive. 
That’s all fine…I just wanted to know about the skates being in touch with the ground because the discussion came across that it was a pirouette or jump that was being used as an example not the grounded twist turn that I posted in the youtube video example.
Like I said…I don’t care one way or the other if COAM is involved or not in the golf swing, because I had never heard of it before, but it piqued my interest and wanted to know farther information just for insight.
Mandrin,
With a vertical jump to initiate motion you root the ground which creates an equal opposite force reaction, allowing the feet to grip the ground and be able to create extension speed of the knees and hips to achieve a vertical jump… Peak knee and hip extension speed is reached before you leave the ground…
Isn’t there an external force applied to the system to create motion? Speed is created before you leave the ground… Coam exists in jumping interesting…
COAM,
Getting to the issue of definitions, which is really what this thread is about… meaning… is COAM the proper term to describe the downswing?
Conserving… what we are doing is conserving the angle of a lever… so we load the lever (wrist cock and wrist rotation)
then we deliver or move that lever to a place where we trigger it like a mouse trap.
It’s not that complicated.
COAM may not be the right term but is certainly a well understood implied term. You might flunk the physics exam, but win the blue ribbon at the physics fair exhibit.
[b][i] …’ CORRECT Steb- who cares about science in the golf swing… that’s what is making it increasingly more and more difficult for golfer’s the world over. Too much useless information that people dream up in the hope it will make them a better player in a quick fix… "
. …“and I guarantee maybe 3 out of the top 5000 golfer’s in the world would have any clue what this thread is about because to be a good golfer…you don’t need to know it”
“I have never heard so much crap in all my life since i have started reading golf forums …I actually sit there and read something 20 times or more and still can’t fathom what it is all about.” [/i][/b]
twomasters,
Science, for you it is all momentous silly crappy complicated stuff as you so darned clearly state in the lines above. And yet on the other hand you spend hours feeding patiently all of chapter 7 of Dante’s book into your computer, perhaps with just two fingers, to start your own thread on exactly the same subject as my thread on COAM. 
That can only be because you are really interested in the subject. Hence you entertain a rather ambivalent discourse. Apparently the right side of your mouth does not know what is coming out of the left side. It is rare that one encounters such an obvious ambivalent behavior, worthy of our dear politicians. 
It has always puzzled me that science, a rather neutral subject, arouse so much passion with some posters. Often they look energetically for some crack, some weak spot, and when finally they realize that after having spent a lot of time they get nowhere they fall back on various insults, and suddenly saying that it is finally of no importance whatsoever, etc, etc… 
You fall back on and glorify the beautiful simplicity of ABS and yet surprisingly lagpressure himself sees the science chapter of Homer Kelley’s book as the pinnacle of golf-science, being epic. Go figure. TGM is not an easy read. If there is one book more cryptic and bizarre, with all this illogic forward referencing, published during the last few hundred of years, I would love to see it. 