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Post by utahgolfer on Mar 23, 2020 19:58:54 GMT -5
I agree that the release of PA#4 begins at p4, but I don't agree that Rahm and Finau have no significant PP#4 and that they don't maintain that pressure point to p5.5. I see a left arm moving in space only due to body rotation, scapula motion, and right lateral bend. I see no independent humerus motion, at least nothing of significance. The left arm is being pulled down with global body motion primarily, as seen in Hogan's demonstration. In essence, their left arms are pinned to PP#4 from p4 to p5.5.
Perhaps we are talking about two different things, but I believe PP#4 plays a key role in every good swing, as a means to promote a body swing and not an arm swing.
Granted, JR and TF have only a brief time from p4 to p5.5, but during this time, I see the body moving the left arm, and not the left arm moving independently.
UG
PS: Looking at Rahm again, he does have some independent left arm motion to about p5, but it looks pivot driven from p5 to p5.5. Finau looks traditional like Hogan.
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Post by dubiousgolfer on Mar 23, 2020 21:17:15 GMT -5
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Post by utahgolfer on Mar 23, 2020 22:16:07 GMT -5
Hi DG and Jeff, Is one purpose of this illustration to show that torso and shoulder rotational torque basically delivers the left arm to p5.5? Is chest pressure in this illustration the same as PP#4 in TGM? DT sure has a flip release swing for a guy with such an amazing brain. Cheers, UG
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Post by imperfectgolfer on Mar 23, 2020 23:01:39 GMT -5
UG,
You wrote-: "I agree that the release of PA#4 begins at p4, but I don't agree that Rahm and Finau have no significant PP#4 and that they don't maintain that pressure point to p5.5. I see a left arm moving in space only due to body rotation, scapula motion, and right lateral bend. I see no independent humerus motion, at least nothing of significance. The left arm is being pulled down with global body motion primarily, as seen in Hogan's demonstration. In essence, their left arms are pinned to PP#4 from p4 to p5.5."
I do not see any significant degree of left arm adduction against the left anterior chest wall in Tony Finau's swing. I only see a small amount of left arm contact with the chest wall near his armpit.
When you state that you see no independent humeral motion, how can you rationally reach that conclusion? The left arm may not be changing its degree of adduction between P4 and P5.5, but it is becoming far less elevated between P4 and P5.5. What is causing that depression of the left arm between P4 and P5.5? How can you exclude that it is not due to muscular contraction of the left shoulder girdle muscles combined with the effect of a right arm adduction maneuver rather than being due to a global pivot motion?
Jeff.
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Post by dubiousgolfer on Mar 23, 2020 23:24:06 GMT -5
Hi UG Far be it from me to question DT's knowledge of physics/maths but I think his assumption about passive tissue interaction and the shortening of the fulcrum radius (ie. using the left pec rather than the left shoulder joint) to increase the hand force is questionable. SMK's model didn't include a right arm so his graphs are not that useful from P4 -P5.5. One thing that DT didn't seem to mention is the 'eccentric force' at the left shoulder joint (caused by the active pivot) that could cause the left arm to rotate (rather than passive tissue interaction) - see image below . I've drawn the force 'F' and just guessed where the COM of the 'arm/club' unit would be with that blue dot. The perpendicular distance from the COM to the tail end of the force is 'r'. This will cause a turning MOF (Moment of Force or a Torque ) T = F x r which will rotate the COM to align with the instantaneous force vector F. So theoretically , the physics is there to explain the rotation of the left arm with just the active pivot . Of course one needs to also take into account the left shoulder girdle contractions and the adduction of the right arm (all without the use of passive tissue interaction of the humerus with the left pec). DG
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Post by utahgolfer on Mar 24, 2020 0:11:28 GMT -5
Jeff, if the humerus is moving independent of the shoulder turn from p4 to p5.5, how can you say the left arm is being truly pulled. When doing the left arm only swing, isn't the idea to move the left arm only via body and shoulder rotation. Isn't left arm speed, during the left arm only swing drill, a function of how fast one rotates the pelvis and shoulders? Do you think the left arm or humerus should move independent of the body rotation from p4 to p5.5? What if the left humerus moves faster than the body rotation? At what point do we call it an arm swing versus a pivot-based swing?
I believe the hands drop vertically from p4 to p5.5 primarily due to the inclined rotation of the shoulders along with right lateral bend and scapula motion. I do not think they drop due to independent humerus abduction, until after p5.5. Jon Ralm is a special case, just like his kinematic sequence tracing illustrates, but he still looks to have a brief period where his humerus piggybacks with the movement of his left chest from p5 to p5.5. But, most players, including Hogan, have a clear period from p4 to p5.5 where the arms only appear to drop vertically due to the inclined rotation of the shoulders, right lateral bend, and scapula motion...and not because of independent humerus abduction.
Do you think right arm/elbow adduction is moving faster than the shoulder turn from p4 to p5.5? If so, then I suppose it could be causing the left humerus to slide across the left chest independently, but if this occurs I believe it is a micro-move and very subtle. I wouldn't see this as a violation of a pivot-driven swing.
I assume we are on the same page, but am happy to be enlightened.
UG
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Post by syllogist on Mar 24, 2020 5:51:29 GMT -5
Hi DG,
I think DT's knowledge of math/engineering is sound, however there's no harm in questioning reasoning used to apply those concepts. A fulcrum point to establish a relationship between force and lever with respect to the left arm is only applicable if one reasons that a muscular force must be applied to "swing" the left arm independent of torso rotation. Consider trying to "swing" the left arm as the club's inertia increases rapidly. If the club were as light as balsa wood, one would have to independently swing the left arm as fast as possible to reach maximum speed as well as intentionally apply positive wrist torque to release the club.
I think that without a right arm in SMK's model, one would have to double the weight of the left arm when considering the math of the triple pendulum to match club speed and club positions of actual golfers. Isn't the weight of the right arm being "pulled" also during torso rotation? Doesn't the weight of the right arm add to the inertia of the club?
Also, if it were optimal to apply a positive left shoulder torque to "swing" the left arm, when does it start and stop given that 1) torso and arm begin to rotate at the same speed and 2) the arm slows when the club creates "tension" between itself and the hands?
To comment on UG's observation of DT's swing and the flippiness, I saw that too. I believe that DT performed his passive tissue connection (left arm continued adduction) just fine but, at the start down, it looks like he applied a positive, idiosyncratic right wrist torque, causing the club to begin to release.
S
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Post by dubiousgolfer on Mar 24, 2020 9:42:13 GMT -5
What I fail to understand from a purely physics perspective is how that 'passive tissue interaction' can push the arm around via a PP#4 pressure point . I have drawn a blue dot on the head of DT's golfer image to represent an axis of upper torso rotation. I've also drawn a yellow concentric circle about the point 'P' where PP#4 should theoretically interact between chest and left humerus. I have then drawn the instantaneous force 'F' that is being applied at point P by the 'Torque' created by the rotation of the torso. You can see that the force F is not in a direction that will push the humerus around in any anti-clockwise direction. The only way a force at point 'P' could be developed to rotate the left arm in an anti-clockwise direction is if the 'arms/club' unit are acting like a 'deadweight' or actively trying to impede the torso rotation and that means resisting its own movement in space. I cannot imagine a golfer trying to resist the motion of the arms in a golf swing when one of the main objectives is to try and maximise hand speed before release. DG
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Post by imperfectgolfer on Mar 24, 2020 10:16:09 GMT -5
UG, You wrote-: " Jeff, if the humerus is moving independent of the shoulder turn from p4 to p5.5, how can you say the left arm is being truly pulled. When doing the left arm only swing, isn't the idea to move the left arm only via body and shoulder rotation. Isn't left arm speed, during the left arm only swing drill, a function of how fast one rotates the pelvis and shoulders? Do you think the left arm or humerus should move independent of the body rotation from p4 to p5.5? What if the left humerus moves faster than the body rotation? At what point do we call it an arm swing versus a pivot-based swing?
I believe the hands drop vertically from p4 to p5.5 primarily due to the inclined rotation of the shoulders along with right lateral bend and scapula motion. I do not think they drop due to independent humerus abduction, until after p5.5." Consider what you are saying. You state that in a left arm-only golf swing action, the left arm is moving due to body and shoulder rotation. If the majority of left arm abduction only happens after P5.5, then you must agree that the depression of the left arm (in the vertical plane) that happens between P4 and P5.5 (where the hands move from being above shoulder level at P4 to being below waist level by P5.5) is due to the "pivot motion and shoulder motion" and that it induces a finite amount of left arm speed by P5.5. Is that left arm speed acquired by P5.5 (before any significant left arm abduction happens) not equal to stating that it represents the release of PA#4? Is the left arm speed acquired before P5.5 not responsible for the majority of a TGM swinger's swing power?
By the way, when I stated that left shoulder girdle muscle contraction can contribute to the speed of left hand motion down the hand arc path, I am not stating that it causes the left arm to move faster than the left shoulder socket's motion (which is secondary to upper torso rotation) that is pulling the left humerus down the plane and I am also not stating that it causes the humerus to move independent of the body rotation. Look at this Hogan video demonstrating the release of PA#4. Do you believe that the speed of left arm motion happening during the release of PA#4 is entirely due to the pivot motion and that there is no contribution from the left shoulder girdle muscles and right arm adduction maneuver?
Jeff.
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Post by dubiousgolfer on Mar 24, 2020 11:25:20 GMT -5
UG
When you said in a previous post " In essence, their left arms are pinned to PP#4 from p4 to p5.5.".
I'm uncertain how that can be achieved unless the torso and arms are using some sort of X-factor pressure via PP#4 . Doesn't this mean that the torso is being rotated anticlockwise while the arms are still in the process of completing backswing (clockwise)?
Also if that is the case , the PP#4 pressure force would be perpendicular to the torso axis of rotation at P4 . In Ben Hogans swing , that would mean a torque force happening immediately on the TSP at the start of the downswing and wouldn't that cause an OTT clubhead swing path?
Here is another video of BH , and under the TGM definition for the release of PA#4 , I can see his left humerus already losing any PP#4 pressure almost immediately at the start of the downswing (check out 1:13 , 1:14 and 1:15 frames).
DG
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Post by utahgolfer on Mar 24, 2020 11:36:49 GMT -5
Jeff: Consider what you are saying. You state that in a left arm-only golf swing action, the left arm is moving due to body and shoulder rotation. If the majority of left arm abduction only happens after P5.5,...
UG: A major amount of left arm abduction occurs before p5.5, especially in players who swing the left arm well above the shoulder, as most do. The left shoulder socket is moving through space and bringing the left humerus with it. Isn't this called left arm abduction since the left arm is moving toward abduction, even though there may be no actual rotation of the humerus within the shoulder socket?
Jeff: Is that left arm speed acquired by P5.5 (before any significant left arm abduction happens) not equal to stating that it represents the release of PA#4?
UG: Yes.
Jeff: Is the left arm speed acquired before P5.5 not responsible for the majority of a TGM swinger's swing power?
UG: Yes, the ability to generate left arm speed is greatest before p5.5. Doesn't the kinematic sequence graph show a greater height of the left arm velocity line before reaching p5.5, than after?
Jeff: Do you believe that the speed of left arm motion happening during the release of PA#4 is entirely due to the pivot motion and that there is no contribution from the left shoulder girdle muscles and right arm adduction maneuver?
UG: No. These muscles are active and play a vital role. I think the muscles directly attached to the left humerus generate isometric tension until p5.5. I believe muscles directly attached to the right humerus generate isotonic tension until p5.5 allowing for right arm adduction. I believe left side scapula muscles (rhomboids) generate some isotonic tension to cause some left scapula retraction during the initial downswing. I believe right side scapula muscles (serratus anterior) generate some isotonic tension to cause some right scapula protraction during the initial downswing.
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Post by imperfectgolfer on Mar 24, 2020 12:49:14 GMT -5
UG, You wrote-: " A major amount of left arm abduction occurs before p5.5, especially in players who swing the left arm well above the shoulder, as most do. The left shoulder socket is moving through space and bringing the left humerus with it. Isn't this called left arm abduction since the left arm is moving toward abduction, even though there may be no actual rotation of the humerus within the shoulder socket?" I seemingly disagree with your definition of left arm abduction. If the upper torso rotates counterclockwise between P4 and P5 and it causes the left arm angle to change from being angled at 12 o'clock at P4 to 9 o'clock at P5, then there may be no left arm abduction happening if the angle between the left arm and the chest wall does not change due to no abductory motion of the left humerus happening within the left shoulder socket joint. Consider Jamie Sadlowski's early downswing. Note the change in his left arm angle between P4 (image 1) and P5 (image 5) due to the counterclockwise rotation of his upper torso that secondarily causes his left arm to depress in the plane of left arm elevation => depression within his left shoulder socket joint. However, there is no change in the angle between the left arm and the anterior chest wall in the plane of left arm adduction => abduction, which means that no left arm abductory motion has happened within the left shoulder socket joint. The first evidence of left arm abduction happens between P5 and P5.5, but most of it happens between P5.5 and P7. Jeff.
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Post by utahgolfer on Mar 24, 2020 15:25:14 GMT -5
Jeff, then we are on the same page. The exact definition of left arm abduction means there is actual humerus rotation within the shoulder socket, however, the functional motion of the the left arm from p4 to p5.5 could still loosely be considered left arm abduction. Is there a better, more accurate name for it?
From p4 to p5.5, most players, I believe, feel a connection between the chest and left biceps (PP#4), and I believe they should. This represents that time when the left arm is being driven by the rotation of the shoulder, and is a key feature in PGA pros swings. To me, this represents the essence of a global body-based golf swing.
Hacks, an appropriate name, will swing their left arm down independent of the left shoulder starting at p4 (strictly defined left arm abduction) and hack down into the ball.
Many amateurs, will maintain PP#4 with no independent left arm motion at p4, but will turn the shoulders too early before a proper hip turn, and rotate the right shoulder too horizontally leading to an OTT or an out to in swing path through the impact zone, leading to pulled shots or pull-slices. This is a timing issue, a violation of the kinematic sequence.
Amateurs will also fail to begin strictly-defined left arm abduction at p5.5, and delay independent left arm motion for too long past p5.5, possibly due to too much tension at PP#4. This will usually cause the swing path to be too in to out, leading to pushed shots to the right. In this case, player will fail to swing the club head left enough into and after impact.
I know these last two swing faults all too well!
So, both the torso-dependent motion of the left arm from p4 to p5.5 is important, as is the independent motion of the left arm from p5.5 to p7+.
UG
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Post by syllogist on Mar 24, 2020 16:06:20 GMT -5
Hi UG,
I agree with amateurs having independent left arm motion starting at P4. However, delaying independent motion until after P5.5 ... wow! ... haven't seen that one. I have asked some golfer friends to hold the adduction angle as long as they could in order to feel the arms/club mass become exceedingly "heavy" and all were quite shocked at how quickly the heavy feeling shows itself, meaning that the left arm is induced to move and the beginning of right arm straightening helps. You refer to rotation as shoulder rotation. Do you mean by this that the rotation of shoulders outpaces the rotation of the torso? That's one way I can envision the adduction angle maintained too long. (I'd have to try it.) Also, I believe that if there is a lot of side tilt (as one might have hitting a driver), isn't P5 for example no longer P5 but a position earlier than P5 since positions can be related to the sideways angle of the torso and not just the ground?
S
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Post by dubiousgolfer on Mar 24, 2020 17:59:58 GMT -5
Hi UG "Hacks, an appropriate name, will swing their left arm down independent of the left shoulder starting at p4 (strictly defined left arm abduction) and hack down into the ball."Unsure whether the proponents of the Leslie King technique would agree with you on that (see below) :-) THE GOLF ACTION IS BASED UPON A FREE SWING OF THE HANDS AND ARMS INDEPENDENT OF THE BODY.golftoday.co.uk/leslie-king-tuition-series-an-end-to-trial-error-golf-lesson-1/Dr Mann has described this type of swing in the chapter below where the left arm releases PA#4 with a reactive pivot. How to Power the Golf Swing www.perfectgolfswingreview.net/power.htm"Many amateurs, will maintain PP#4 with no independent left arm motion at p4, but will turn the shoulders too early before a proper hip turn, and rotate the right shoulder too horizontally leading to an OTT or an out to in swing path through the impact zone, leading to pulled shots or pull-slices. This is a timing issue, a violation of the kinematic sequence"This is what I used to do based on David Leadbetters old instruction concepts about the 'Dog Wagging the Tail' where the body is the main powerhouse for the swinging arms. Problem was I had virtually zero pelvic/torso (hula hula) separability into my late 30's, so when I used the correct kinematic sequence from the ground up , my pelvis and upper torso rotated immediately together and I ended up with all sorts of errant shots (mostly snap hooks for me). I nearly gave up the game until , would you believe it , I started using Leslie King tuition series link above. I then started to hit the ball straighter and could play reasonably well enough to get around the course without too much embarrassment. Is your concept on the golf swing more in accord with Dr Manns old article below? How to Maximise Wrist Lag and Avoid Casting www.perfectgolfswingreview.net/casting.htmDG
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