This SHOULD end the Driver down or up debate...
- Thread starter Brian Manzella
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TGManMachine
New
Such confusion, and inability to understand body biomechanics. Let's try this again.
The left shoulder is moving up at impact while the right shoulder is rotating down. The unflexing of the right elbow is almost completed and the right hand is sustaining the lag with a flexed wrist and Pressure Point #3.
Rotation of the club around the wrist joints is virtually completed because a flat left wrist has been established. The dominant rotation and rotative center is between the shoulders, and this is confirmed because the upper left arm no longer rotates around the left shoulder joint into impact.
It seems that some here what to ignore the fact the left and right arms are rotating in unison with the shoulders, and no longer around the shoulder joints. The only way the left arm can be the rotative center for the left arm if in fact the left arm continued it's rotation around the left shoulder joint and disconnected from the left pec. Just look at brianman's swing.gif in stop action and you will see both arms rotating in unison with the upper torso. Therefore the rotative center of the golf swing into impact must reside in the upper chest.
Please gracefully admit that is what is happening in the golf swing at impact, and it is adequately demonstrated in brianman's own swing.gif. As for Mobley and Howell, it is obvious that they have delayed release deep into the down swing, and their release is not fully completed and have not yet achieved a fully flat left wrist. They are rotating their arm-club assembly around their shoulder axis while allowing release to finish through impact. This provides the indirect illusion and incorrect conclusion that the driver head must be descending at impact.
In fact, the Keuhne launch monitor data indicates that he has a positive attack angle of 2.8* and a forward shaft lean. What we cannot see is the kicked forward position of the driver head at impact, and without knowing that you cannot say that the driver head is on a descending path because the shaft has a forward lean.
Those that hold on to the logic that a forward leaning shaft must result in a descending attack angle, are just not cognizant of the full dynamic positioning of the club head and dominant rotative center located between the shoulder around the spinal axis.
Just draw a line from the shoulder rotative center to the driver head at impact to achieve the ascending attack angle. How many times do I have to repeat these facts before it sinks in?
The left shoulder is moving up at impact while the right shoulder is rotating down. The unflexing of the right elbow is almost completed and the right hand is sustaining the lag with a flexed wrist and Pressure Point #3.
Rotation of the club around the wrist joints is virtually completed because a flat left wrist has been established. The dominant rotation and rotative center is between the shoulders, and this is confirmed because the upper left arm no longer rotates around the left shoulder joint into impact.
It seems that some here what to ignore the fact the left and right arms are rotating in unison with the shoulders, and no longer around the shoulder joints. The only way the left arm can be the rotative center for the left arm if in fact the left arm continued it's rotation around the left shoulder joint and disconnected from the left pec. Just look at brianman's swing.gif in stop action and you will see both arms rotating in unison with the upper torso. Therefore the rotative center of the golf swing into impact must reside in the upper chest.
Please gracefully admit that is what is happening in the golf swing at impact, and it is adequately demonstrated in brianman's own swing.gif. As for Mobley and Howell, it is obvious that they have delayed release deep into the down swing, and their release is not fully completed and have not yet achieved a fully flat left wrist. They are rotating their arm-club assembly around their shoulder axis while allowing release to finish through impact. This provides the indirect illusion and incorrect conclusion that the driver head must be descending at impact.
In fact, the Keuhne launch monitor data indicates that he has a positive attack angle of 2.8* and a forward shaft lean. What we cannot see is the kicked forward position of the driver head at impact, and without knowing that you cannot say that the driver head is on a descending path because the shaft has a forward lean.
Those that hold on to the logic that a forward leaning shaft must result in a descending attack angle, are just not cognizant of the full dynamic positioning of the club head and dominant rotative center located between the shoulder around the spinal axis.
Just draw a line from the shoulder rotative center to the driver head at impact to achieve the ascending attack angle. How many times do I have to repeat these facts before it sinks in?
Brian Manzella
Administrator
Ok.
Let's assume that we have a driver shaft that is not flexing forward or backward at impact.
THE BOTTOM OF THE SWING WITH A FLAT LEFT WRIST PRESENT IS THE LEFT SHOULDER.
http://homepage.mac.com/brianmanzella/.Movies/flipperclip.mov
Let's assume that we have a driver shaft that is not flexing forward or backward at impact.
THE BOTTOM OF THE SWING WITH A FLAT LEFT WRIST PRESENT IS THE LEFT SHOULDER.
http://homepage.mac.com/brianmanzella/.Movies/flipperclip.mov
TGManMachine
New
Thank you brianman for going to all that work to present your video on this important subject. I must apologize because I am not able to get audio even with the volume up, so I must make some assumptions on what you may be saying and from what you illustrate about the swinging of the left arm around your shoulder.
I can agree with you as you show it that the left shoulder joint represents the center of the swing radius resulting in the bottom of the swing being directly under it assuming a flat left wrist. I would also agree with you that your example is correct if the shoulders are not rotating and are statically horizontal to the ground.
However, in a real golf swing, the left arm rotation essentially stops as the arms and club are bottoming out because the left upper arm is connected to the left pec and both rotate in unison around the shoulder rotation center. Please read 2-M-4 on Body Power. This is nicely illustrated in the swing.gif of your signature swing.
Furthermore in the full golf swing, since the left shoulder is obviously rotating and pulling the left arm UP and BACK because it has passed horizontal (as shown in the Mobley and Howell pics on this thread), the left arm CANNOT be the rotative radius in a full golf swing. The rotative center must be somewhere in the vicinity of the shoulder span or Stationary Head which is held back due to the lateral Spinal Axis Tilt. Whether it is the Head or the shoulder span axis, both arms are rotating in unison with the torso rotation and this geometry would contradict your video example.
This seems so evident in your own signature swing.gif. I hope I have properly interpreted what you presented in your video.
I can agree with you as you show it that the left shoulder joint represents the center of the swing radius resulting in the bottom of the swing being directly under it assuming a flat left wrist. I would also agree with you that your example is correct if the shoulders are not rotating and are statically horizontal to the ground.
However, in a real golf swing, the left arm rotation essentially stops as the arms and club are bottoming out because the left upper arm is connected to the left pec and both rotate in unison around the shoulder rotation center. Please read 2-M-4 on Body Power. This is nicely illustrated in the swing.gif of your signature swing.
Furthermore in the full golf swing, since the left shoulder is obviously rotating and pulling the left arm UP and BACK because it has passed horizontal (as shown in the Mobley and Howell pics on this thread), the left arm CANNOT be the rotative radius in a full golf swing. The rotative center must be somewhere in the vicinity of the shoulder span or Stationary Head which is held back due to the lateral Spinal Axis Tilt. Whether it is the Head or the shoulder span axis, both arms are rotating in unison with the torso rotation and this geometry would contradict your video example.
This seems so evident in your own signature swing.gif. I hope I have properly interpreted what you presented in your video.
Brian Manzella
Administrator
Nope.
TGManMachine
New
So where does your audio message depart from the geometry you show and the text of your accompanying message, namely:
"Let's assume that we have a driver shaft that is not flexing forward or backward at impact.
THE BOTTOM OF THE SWING WITH A FLAT LEFT WRIST PRESENT IS THE LEFT SHOULDER."
Thanks for your help.
"Let's assume that we have a driver shaft that is not flexing forward or backward at impact.
THE BOTTOM OF THE SWING WITH A FLAT LEFT WRIST PRESENT IS THE LEFT SHOULDER."
Thanks for your help.
Brian Manzella
Administrator
The shoulder's position at impact is IRRELEVANT to where low point will be.
Wherever it is, there it is.
Wherever it is, there it is.
Here is a link with photos of eight pros and 6 of the pics the clubhead is clearly heading downward.
http://golfdigest.com/instruction/s...uction/swingsequences/gd200407nessimpact.html
http://golfdigest.com/instruction/s...uction/swingsequences/gd200407nessimpact.html
The only time that the bottom of the swing is guaranteed to be even with the left shoulder is when the left shoulder is stationary. However, this is not the case during the swing. There is no disagreement that the left shoulder is moving upwards during the swing, thus changing the bottom point of club path. It’s clear from the TM system figures that the clubhead is going UP at a 2.8 degree angle with respect to the ground. However, because his clubshaft is still bent forward, the club is moving DOWN with respect to the shoulder.
I’ve created a couple graphs to illustrate what I’m saying. In the first picture, the left shoulder is stationary (the red dot). Using excel, I have calculated the clubhead path assuming that the club and arm act as a straight line of fixed length. This path is shown in green. As expected, the bottom of the path is even with the left shoulder.
The second figure shows the path of the clubhead with an upward shoulder motion (the shoulder moves from the blue dot to the red dot.) The resulting path was calculated assuming that the shoulder moves upward at a constant rate, and that the club and arm act as a straight line of fixed length. As you can see, the path, shown in green, hits its lowest point well before it is even with the left shoulder. At any point between this bottom point and the point even with the left shoulder, the clubhead is traveling UPWARDS, but the clubshaft would still be leaning forward. This appears to be the case in the TM analysis shown above.
image38.webshots.com/38/9/76/7/316797607LPDptZ_ph.jpg
image40.webshots.com/41/9/78/67/316797867sZAzTz_ph.jpg
This does not guarantee that the clubhead will be traveling upward for a driver, but does show how it is possible for the shaft to be leaning forward and the clubhead still travelling upward. If the left shoulder does not move upward very much (as Mickelson says he does), it would be quite possible to be hitting down on the driver.
I’ve created a couple graphs to illustrate what I’m saying. In the first picture, the left shoulder is stationary (the red dot). Using excel, I have calculated the clubhead path assuming that the club and arm act as a straight line of fixed length. This path is shown in green. As expected, the bottom of the path is even with the left shoulder.
The second figure shows the path of the clubhead with an upward shoulder motion (the shoulder moves from the blue dot to the red dot.) The resulting path was calculated assuming that the shoulder moves upward at a constant rate, and that the club and arm act as a straight line of fixed length. As you can see, the path, shown in green, hits its lowest point well before it is even with the left shoulder. At any point between this bottom point and the point even with the left shoulder, the clubhead is traveling UPWARDS, but the clubshaft would still be leaning forward. This appears to be the case in the TM analysis shown above.
image38.webshots.com/38/9/76/7/316797607LPDptZ_ph.jpg
image40.webshots.com/41/9/78/67/316797867sZAzTz_ph.jpg
This does not guarantee that the clubhead will be traveling upward for a driver, but does show how it is possible for the shaft to be leaning forward and the clubhead still travelling upward. If the left shoulder does not move upward very much (as Mickelson says he does), it would be quite possible to be hitting down on the driver.
Jim Kobylinski
Super Moderator
As per brian:
"The left shoulder moving UP
MAKES the club go down!!!
Watch...
http://homepage.mac.com/brianmanzella/.Movies/leftshoulderup.mov "
Please watch the movie....
"The left shoulder moving UP
MAKES the club go down!!!
Watch...
http://homepage.mac.com/brianmanzella/.Movies/leftshoulderup.mov "
Please watch the movie....
- bold by Vaako -
This assumption is a bit too bold.
This line isn't fixed length thanks to wrist joint. Wrist cock and wrist (forearm) roll - accumulators 2 and 3 - move the clubhead down. The rate of descent from wrist movements is greater then the rate of ascent from shoulder movement.
Untill we reach the low point under the shoulder joint.
Vaako
As an after thought - does anybody know how the MATT system really works?
In this case, is it measuring the driverhead baseplate roll around the center-of-mass caused by impact?
- or -
Is it measuring the true path of driverhead center-of-mass?
Vaako "Being something, but not paranoid."
In this case, is it measuring the driverhead baseplate roll around the center-of-mass caused by impact?
- or -
Is it measuring the true path of driverhead center-of-mass?
Vaako "Being something, but not paranoid."
Jim -
I'm not asserting that the driver should contact the ball on the upswing (because I really don't know better than anybody else). I'm just showing that it is very possible for the clubhead to be moving on an upward path while the shaft is leaning forward.
Vaako -
You're right - I have made a LARGE assumption in my model, and one that is not correct for the vast majority of the swing. However, during (or just after) impact, when the back of the left hand is facing the target, I think it's a reasonable approximation. Your objection is certainly worth considering, and that's why I mentioned it. If anyone could come up with a perfect model, we wouldn't have this debate!
I'm not asserting that the driver should contact the ball on the upswing (because I really don't know better than anybody else). I'm just showing that it is very possible for the clubhead to be moving on an upward path while the shaft is leaning forward.
Vaako -
You're right - I have made a LARGE assumption in my model, and one that is not correct for the vast majority of the swing. However, during (or just after) impact, when the back of the left hand is facing the target, I think it's a reasonable approximation. Your objection is certainly worth considering, and that's why I mentioned it. If anyone could come up with a perfect model, we wouldn't have this debate!
Another afterthought -
If the arm-club is not considered to be the same length throughout the bottom of the swing, then how does TGM come to the conclusion that position just under the shoulder is the bottom of the swing? I always assumed that was how that conclusion was drawn (i.e. assuming that the lowest point on a circle is directly below the centerpoint of the circle).
If the arm-club is not considered to be the same length throughout the bottom of the swing, then how does TGM come to the conclusion that position just under the shoulder is the bottom of the swing? I always assumed that was how that conclusion was drawn (i.e. assuming that the lowest point on a circle is directly below the centerpoint of the circle).
Objection is such a strong word.
Your model - or calculation - is perfectly applicable to the last ½ inch before and after impact. There is too much going on in the swing to start arguing it's merits; The saft droops, kicks, rotates and then some.
The graphics you made seem - to me at least - a touch too dramatic. Like taking your model out of it's domain and generalizing it to whole swing. As long as you stick to below left should plus/minus inch or two, you're good. Start talking about below sternum and wrist joint movements kick in.
The Perfect Model(TM) in this situation would be a rather involved dynamic Finete Element Model with bazillion cells. Not something you casually piece together.
Vaako
Burner
New
Long drivers are looking to do just that - drive long - no other consideration.
Driving long, in their world, includes maximising the potential for forward roll once the ball gets back on the ground. Hence the lower loft and leaning back in order to gain a little initial height before roll does the real work for them. They are not too concerned how the ball gets out there so long as it does.
Golfers operate under different criteria where flight takes precedence over roll and the outcome of the drive has a direct bearing on the next shot.
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