|
Post by imperfectgolfer on Aug 29, 2013 11:08:33 GMT -5
See this Jeffy-forum thread - jeffygolf.com/showthread.php?773-Convoluted-thinkingKM quotes Cheetham and Kwon. Where is this discussion happening? Can I view the discussion? Can I participate in the discussion? I would like to ask Cheetham to defend his wild claims that i) spinning of the left foot through impact + jumping off the ground at impact increases torque on the handle and increases wrist release speed; and ii) that slowing of the club motion post-impact causes the shoulder rotary motion to accelerate. Jeff.
|
|
|
Post by burner on Aug 29, 2013 17:22:03 GMT -5
Try joining Facebook and look for the group Golf Biomechanists.
|
|
|
Post by imperfectgolfer on Aug 29, 2013 19:24:19 GMT -5
Burner,
I am now a Facebook member and I can find a reference to the "Golf Biomechanists" group, but it is a closed group. How can one read that group's posts?
Jeff.
|
|
|
Post by richie3jack on Aug 30, 2013 8:34:09 GMT -5
You have to be invited onto the forum.
3JACK
|
|
|
Post by imperfectgolfer on Aug 30, 2013 14:36:24 GMT -5
3jack,
Thanks. I cannot imagine many of the members being willing to invite a critic who unrelentingly questions the validity of any golf instructor's opinions re: golf swing mechanics/biomechanics.
Jeff.
|
|
|
Post by richie3jack on Sept 3, 2013 8:40:27 GMT -5
I thought Kelvin asked some good questions and was eventually banned from the forum. Part of me understands it as people like Dr. Kwon, Phil Cheetham and others are giving away their thoughts and research for free and I can understand the feeling that they should not be antagonized over it. However, I thought Kelvin pretty much behaved himself although I will admit I didn't read nearly every post.
But, if people like Dr. Kwon and Cheetham decide they've had enough, then they don't have a forum.
I've found the work of Kwon, MacKenzie, Cheetham, etc to be interesting although I don't quite buy into taking what they say at face value because they have measurement tools and had a Doctor beside their name. It's a fine line between 'agree with me or else I'm leaving' and asking critical questions.
3JACK
|
|
|
Post by imperfectgolfer on Sept 3, 2013 10:01:36 GMT -5
Rich,
How do you get to read what they say? Are you a member of that closed group?
Jeff.
|
|
|
Post by richie3jack on Sept 3, 2013 12:37:40 GMT -5
I am a member.
3JACK
|
|
|
Post by virtuoso on Sept 3, 2013 14:03:13 GMT -5
I thought Kelvin asked some good questions and was eventually banned from the forum. Part of me understands it as people like Dr. Kwon, Phil Cheetham and others are giving away their thoughts and research for free and I can understand the feeling that they should not be antagonized over it. However, I thought Kelvin pretty much behaved himself although I will admit I didn't read nearly every post. But, if people like Dr. Kwon and Cheetham decide they've had enough, then they don't have a forum. I've found the work of Kwon, MacKenzie, Cheetham, etc to be interesting although I don't quite buy into taking what they say at face value because they have measurement tools and had a Doctor beside their name. It's a fine line between 'agree with me or else I'm leaving' and asking critical questions. 3JACK Richie, its fine that Kelvin, et al, disagrees. i don't think he should have been banned but now he's also saying that the biomechanists are corrupt as well. That's pretty bad. There is no evidence to support that.
|
|
|
Post by richie3jack on Sept 4, 2013 8:00:24 GMT -5
My feeling on biomechanical experts based on dealing with them is that if you asked 5 of them to explain something, you would get 5 very different answers. Each one of them are convinced that they have the absolute correct answer and they really try to sell it.
I think Kelvin's complaint is that he has questions and criticisms of different parts of their work, mainly where the sensors are located and what they are measuring and then verifying their system. Those are fairly valid points to bring up.
They often discuss being 'peer reviewed' and I have had work 'peer reviewed' when I was in college. In this case, I have felt that Kelvin's questions and criticisms are right in line with what a peer review would ask. Yet it's been an 'agree with me or else I'm leaving' attitude. Therefore, it's hard for me to take umbrage with Kelvin's feelings.
I understand the issues Nick Chertock faces as well. Although he can't tell me that Kelvin has been anywhere near as antagonistic as Mike Finney has been on that forum and other forums.
3JACK
|
|
|
Post by chipitin on Sept 4, 2013 9:17:52 GMT -5
Interesting, as one could say the exact same thing about Kelvin M.'s research. Dr. Mann has shown many problems with K.M.'s work. Also is K.M. a peer? He read a paper by Carol Putnam and totally misinterpreted what was in the paper, Sasho M. had to straighten him out on it, so I wouldn't put any faith in what K.M. has to offer as a " peer" review.
Kelvin used k-vest as his 3d experience, I mean really and 2d video to come up with his theories. I would suggest he's not quite in the same league as the other scientists as of yet.
Anyone can question anything. And speaking of selling ideas and other items I think Kelvin is a peer.
And nothing you said shows Kelvins claim that the biomechanists are corrupt is true, more like name calling because he doesn't like the answers and treatment he received.
|
|
|
Post by chipitin on Sept 4, 2013 9:28:00 GMT -5
One of Mike Finney's posts
This debate is not about the validity of the measurements. Dr. Kwon, Dr. Duffey, Dr. Mackenzie, Dr. Neal, and Mr. Cheetham have all chimed in on the different 3D motion capture system's hardware and software, the axes used, and several other factors that affect the output.
This debate is about a group of people who think that certain elite strikers of the ball somehow overcome human limitations and peak their pelvis speed at impact of full golf swings. They use "video evidence" to make "qualitative observations" that basically refute the already captured data of tour players.
They have done two things to deflect from the real debate. They have changed course midstream and said that the "second fire" is now the reason that they can qualitatively see the elite strikers' superiority. This "second fire" consists of translational movements like hip slide, thrust, and lift. Six months ago, their claim was that these same elite strikers were overcoming normal human limitations and keeping their rotational speeds constant through impact or in some cases they were accelerating.
When the Drs. said "we are not seeing that", they moved to the "translation" is "rotation" argument. The Drs. again said no - they must be separated. They didn't like that and they took to another website to discredit all who did not agree with them.
The second tactic has been to question biomechanics as a science. They cite poor New Zealand cricket batting as a biomechanics failure and wonder aloud if this same thing will happen in golf (meanwhile, every tour in the world had their winners shooting 20 under par this week). If they are to be successful, they must throw actual measurements to the side because they are not agreeing with their hypotheses. They must have the right to make their qualitative observations - from video or a markerless 3D system - to exist.
So here we are - an observational group grabbing questionable 3D data and using it to prove their point. Dr. Kwon said it best - it's a deadly mix.
|
|
|
Post by chipitin on Sept 4, 2013 9:49:11 GMT -5
Some more...
by Phil Cheatham from AMM:
"If the axis is not parallel to the anatomical turn axis (the up/down axis through the pelvis that tilts with the pelvis) then you are not looking at turn you are looking at some combination of side bend, forward bend and turn combined. When I talk about pelvic turn I am talking about rotation around the up/down axis.
The turning rotation speed of the pelvis around its up/down axis accelerates in the downswing then decelerates before impact in elite level golfers."
|
|
|
Post by chipitin on Sept 4, 2013 10:02:03 GMT -5
Sasho M. straightening Kelvin M. out on Carol P.'s paper.
I do not believe that Carol Putnam would consider simultaneous peaking to be the ideal motion in golf (or most other striking and throwing actions).
I took a two university classes from Carol during my undergrad degree at Dalhousie. One was Advanced Biomechanics; it was a small class (< 10 students), so there was a lot of time to have in-depth conversation regarding her segment interaction work. We spent a lot of time covering the equations presented in her 1993 paper (the one that Kelvin Miyahira quoted from). In the 1993 paper, when Carol describes simultaneous peaking as being ideal from a KINEMATIC perspective, those are not her own thoughts; rather, they are the theories of other researchers. She is attempting to demonstrate the importance of the research she is about to present in the paper on what CAUSES the motion of each segment in a linked system. Her research could be considered an initial starting point for understanding why a proximal-to-distal sequence is favoured, over simultaneous peaking, in most throwing and striking actions.
IMO, I wouldn’t even say simultaneous peaking is ideal from a kinematic perspective. Simultaneous peaking is ideal from a mathematical perspective when one only analyzes the kinematic constraint equations of a linked system and doesn’t realize that forces (and torques) must act on masses (and moment s of inertia) in order to generate the ideal motions. Situations in which simultaneous peaking would be ideal would be the exception, not the norm.
|
|
|
Post by richie3jack on Sept 4, 2013 13:17:48 GMT -5
Interesting, as one could say the exact same thing about Kelvin M.'s research. Dr. Mann has shown many problems with K.M.'s work. Well, two wrongs don't make a right. I didn't say he was. I said the questions and criticisms he has asked is right in line with what would be questioned and criticized in a peer review. Many of these doctors, researchers and scientists consistently cry for Peer Reviews, then when somebody comes along and ask similar questions and has similar criticisms that a Peer Review would present, they get upset and act like they are beyond reproach. Like I stated earlier, I haven't read every post made by everybody involved. From what I have read the 'name calling' consisted of a claim of 'scientific bias' from Kelvin and asking for verification of the accuracy of the measuring systems used as well as where the sensors have been placed. This is all right in line with what would be asked in a peer review. I don't know if KM resorted to name calling (again, haven't read every post), but I would not characterize what I have read from him as calling them corrupt. More of a criticism and stating what he believes the flaws in their work is. Surely, KM could be incorrect in his criticism and claims. But, I don't think it was something worth banning him over and it makes the group appear to be afraid to have their research questioned. 3JACK
|
|