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Post by utahgolfer on Mar 24, 2020 19:52:02 GMT -5
S and DG,
I haven't looked at Dr. Mann's website for awhile. Always fun to peruse. I am certainly rehashing the same material as a way to distill out possible new insights.
The common term, as illustrated in that review article, is "retain the angle". Here, they are speaking of the often discussed left wrist lag angle between the left forearm and club shaft, from p4 to about p5.5.
Jeff also speaks of Ben Hogan doing his pump drill and delivering the club to p5.5 without active arm motion, only due to hip and body rotation. Similarly, in this post, I've tried to better understand the idea of left arm adduction or motion from p4 to p5.5.
Basically, I have also said it is ideal to "retain the angle", but this time I am referring to the angle between the left arm and shoulders...that this doesn't change from p4 to p5.5.
DG, sometimes it does help to just swing the arms when a golfer lacks hula hula flexibility. I'm glad that has worked for you. It would great if Jeff would post a thread on how he has been able to swing with an active pivot even though he also has limited hula hula flexibility. His determination to find a solution is remarkable, and could be of benefit to inflexible senior golfers like yourself.
Also, it can sometimes help certain golfers to just swing with their arms and get them moving. In my experience, some golfers might hold the left biceps against the chest for too long, well past p5.5, and either hit push shots to the right due to a rightward swing path issue or hit slice shots due to a poor release of PA# 2 and 3. The solution may be to do the Leslie King method as a remedial drill. But, as we know, the best approach is to strive to perform a global body-based swing, like PGA pros.
S, I'm just saying the same as in the previous example, that some players keep the left biceps pinned against the left chest for too long, past p5.5, and this leads to a host of problems. The problem isn't that the shoulders rotate faster than the hips. In fact, that should happen as the downswing occurs with a proper kinematic sequence. The problem is that the left arm simply holds on to PP#4 for too long, well past p5.5.
Yes, the p-system is going to be described the same for all clubs, but the relative position in space would differ based on the length of the club and swing mechanics, from the wedge to driver swing.
UG
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Post by dubiousgolfer on Mar 24, 2020 20:50:49 GMT -5
I found this slide in Phil Cheethams .pdf document below (apologies for the size of these images as I am having problems with my computer office packages ). www.philcheetham.com/wp-content/uploads/2015/10/Biomechanics-Instructors-Should-Know-Part-1-by-Phil-Cheetham-10-2015.pdfOne thing I noticed was the slope of the blue line (ie. arm rotational speed ) after P4. The degree of slope is the angular acceleration and one can see that the arm is being accelerated slightly more than the thorax (Green line) whose slope is flatter. But the rotational speed of the thorax is more than the left arm at P4. How can that be? I can only assume that there is no pinning of the left arm to the thorax , otherwise the speed and slopes of the blue and green lines would be the same. There must be some separation between the thorax and left arm in the beginning of the downswing. DG
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Post by utahgolfer on Mar 24, 2020 22:09:22 GMT -5
DG,
Velocity and acceleration can be two different measures. The torso could be moving faster (velocity) but the left arm is increasing in speed at a faster rate (acceleration).
I think the left arm could be pinned but could still have increased acceleration due to left scapula retraction and right scapula protraction. Or, this player had some slight independent left arm motion from p4 to p5.5.
This is my take, but Jeff is the expert.
UG
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Post by syllogist on Mar 25, 2020 5:27:31 GMT -5
Hi UG,
In Cheetham's graph, the thorax can rotate faster than the left arm if the adduction angle of the left arm decreases during the initial thorax rotation. This doesn't have to happen but some do it. (Arm swing not quite completed during backswing, while thorax begins to rotate with relaxed arm)
(My question was whether your adduction angle remained what you believed to be too long because you accelerated the shoulder girdle independent of the torso (thorax) - not the hips.) I'm just curious how you held the left arm back - if not shoulder girdle acceleration, muscular effort of muscles around the left shoulder?
By the way, I'm not a Leslie King fan.
S
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Post by utahgolfer on Mar 25, 2020 9:43:16 GMT -5
Hi S,
I’ve theorized it could be due to too much PP#4 tension. That could be true. But, yes, it could also be that the left arm is being left behind due to not enough isometric shoulder girdle muscle activation holding the left arm in place.
I assume this second problem could prevent the proper torso driven motion of the left arm at p4 or the proper acceleration of left arm abduction after p5.5.
But, I’ve probably speculated enough. We need Jeff to get this back on the original topic...rethinking the release of PA#4 and how the left arm, torso rotation, and shoulder girdle muscles appear to interact with one another from p4 to p5.5 based on his thinking and observations.
UG
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Post by imperfectgolfer on Mar 25, 2020 13:13:58 GMT -5
UG, I disagree with many of your opinions and here are some examples of statements that you have made in previous posts where I disagree with your opinions. You wrote-: 1. "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.
2. 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?
3. 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?
4. But, at p4, the idea is that PP#4 represents a stable non-moving humerus on the chest wall for all players. The humerus essentially does not slide or move from that PP#4 until p5.5.
5. I would suggest the same for Ryan Moore, although he may have some initial downward sliding of the left humerus from p4 to p4.5. But, at p4.5, the same applies to him and other golfers who have extremely upright swings (Jim Furyk and Matthew Wolff). They need to reconnect PP#4 as soon as possible and stop all independent humerus motion as soon as possible.
6. 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.
7. 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."
You have expressed opinions where you have opined that all left arm motions between P4 and P5.5 in a TGM swinger should be due to body rotation and that there should be no independent left humerus motions happening during that time period. You also have inferred that a TGM swinger should load PP#4 at P4 and maintain a loaded PP#4 unchanged all the way between P4 and P5.5. You seem to have conceded that Ryan Moore may have some independent sliding motion of his left humerus between P4 to P4.5, but you then state that he must re-connect PP#4 as soon as possible, which implies that he somehow disconnected PP#4 between P4 and P4.5.
I disagree with all those opinions and here is my present-day thinking on this topic.
Consider a "pure" lead arm only golf swing action, which is quintessentially a pivot-induced TGM swinging action.
Here are capture images of Logan Aldridge's hand arc path.
Note that he loads his lead arm across his shoulder turn angle at P4 and that he probably has a sense of PP#4 loading at P4.
How does he power his lead arm motion? I suspect that it is due to the clockwise rotation of his torso that moves the lead shoulder targetwards. How does the targetwards motion of his lead shoulder socket cause the hand arc path to be angled more downwards than the more horizontal motion of his lead shoulder socket? I think that it is primarily due to the fact that his lead humerus is trapped under the lead shoulder socket, and it gets pulled downwards when the lead shoulder socket's motion starts the downswing motion of the lead arm. Could he be using his lead shoulder girdle muscles to independently control the hand arc path's directional motion between P4 and P5.5? Possibly, but not necessarily, because he could do it by simply maintaining his spinal bend inclination angle while he rotates his torso clockwise. Does he increase PP#4 pressure as he transitions into the downswing? Probably - because he starts the downswing with a clockwise body rotation while not independently moving his passive lead arm. When does the sense of loaded pressure at PP#4 starts to decrease? I suspect that it starts to decrease after ~P4.75 (image 2) when the lead arm first starts to abduct away from the chest wall. I don't have any capture image of his golf swing at P5.5 so I will use Hogan's golf swing as a similar example of a TGM swinging action where the lead arm is loaded across the shoulder turn angle at P4.
Image 1 is at P4, image 2 is at P4.5 and image 3 is at P5 and image 5 is at P5.5.
I can imagine that Hogan's sense of pressure at PP#4 is increasing between P4 and P4.5 because he starts his downswing with a counterclockwise rotation of the torso (pelvis first => upper torso secondarily) while his left arm is passive. However, by P5 (image 3) the sense of pressure at PP#4 should be rapidly decreasing because his left arm is already starting to move faster than the upper torso, and you can already see an increased degree of "air gap" between his left humerus and his anterior chest wall at the location of PP#4 (image 3). Between P5 (image 3) and P5.5 (image 5) he should have far less sense of pressure at PP#4 because his lead arm is traveling much faster than his upper torso - even though the lead humeral head is still being pulled along by by the lead shoulder socket's motion in a targetwards direction. If Hogan's lead arm is traveling faster than his upper torso (as evidenced by the increased "air gap" between his left arm and his chest wall in the plane of left arm adduction => abduction that is seen between image 3 and image 5), then it makes no sense to state that there is no independent left arm motion happening between P4 and P5.5 when you stated-: "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."
What about independent left arm motion happening between P4 and P5 in a TGM swinging action?
Consider Ryan Moore's downswing action between P4 and P5.5.
Image 1 is at P4, image 2 is at P4.25, image 3 is at P5, image 4 is just passed P5 and image 5 is at P5.5.
Look at his hand arc path between P4 and P4.25. Note that he has already squared his pelvis and his upper torso is starting to rotate, but his hands are not moving downplane (as seen in the Logan Aldridge capture images), and his hands are actually moving away from the ball-target line and also downwards. What is causing his hands to move atypically? Surely, it is due to independent left arm motion happening secondary to his active right arm adduction phenomenon that radically shallows his left arm angle between P4 and P5. Does that independent left arm motion ( = independent of the body rotation) happening between P4 and P5 decrease his sense of pressure at PP#4? Not necessarily - because although his left arm is sliding down the front of his torso, it is not altering his left arm's degree of adduction in the plane of left arm adduction => abduction. I suspect that his sense of pressure-loading at PP#4 decreases soon after P5 (image 4) when the left arm is traveling faster than the upper torso and that it must be significantly less by P5.5 (image 5).
Now, consider another TGM swinger - pro golfer Jon Rahm.
Here is his kinematic sequence graph.
Note that his pelvis and upper torso are already rotating counterclockwise during his late backswing, and that his upper torso is traveling faster than his left arm before P4. However, note that his left arm starts to accelerate just before P4 and it travels faster than his upper torso very soon after P4 (eg. P4.25). How is that possible if there should be no independent motion of the left arm in the early downswing and if the left arm is only being pulled passively by the left shoulder socket's motion in a targetwards direction at the start of the downswing?
Consider Jon Rahm's hand arc path.
Image 1 is at P4, image 2 is at P5 and image 3 is P5.5.
Note his very steep hand arc path between P4 and P5 - compared to the far less steep hand arc path of Logan Aldridge and Ben Hogan. Surely, it must be due to some independent left arm motion (= independent of body rotation pulling the left arm down the plane) happening due to an active right arm adduction maneuver +/- some left shoulder girdle muscle activity that depresses the left arm in the left shoulder socket). I also suspect that Jon Rahm still has a sense of pressure loading pressure at PP#4 at P4, but far less at P5.5 when the left arm is moving away from his chest wall.
Finally, it is obviously still possible for Jon Rahm to have some degree of independent left arm motion happening within his left shoulder socket between P4 and P5.5 while the left shoulder socket is still moving targetwards (and thereby still pulling the left humeral head along with it) - thereby contradicting any opinion that it is not possible to have independent left arm motion happening at the same time if the left arm is being actively pulled by the body rotation between P4 and P5.5 in a TGM swinging action.
Jeff.
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Post by utahgolfer on Mar 25, 2020 14:33:19 GMT -5
Jeff, is this your new thinking on the release of PA#4? Did you believe in the past that the left arm was only pulled along the abduction plane due to body rotation or have you always beileved that there has been some independent left arm motion from p4 onward? In other words, have you believed that there is always some true left arm abduction from the beginning of p4 in all elite golfers?
Here is a comparison between Jon Rahm and Adam Scott. Would it be fair to say there is a slower phase of left arm abduction from p4 to p5.5, and a faster phase of left arm abduction from p5.5 to p6.5?
Do you believe that JR has a faster phase of left abduction than AS from p4 to p5.5? Do you see any part of AS's swing where his shoulders and left arm are moving at the same rotational speed between p4 and p5.5?
UG
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Post by imperfectgolfer on Mar 25, 2020 15:19:40 GMT -5
UG, You wrote-: " Jeff, is this your new thinking on the release of PA#4? Did you believe in the past that the left arm was only pulled along the abduction plane due to body rotation or have you always beileved that there has been some independent left arm motion from p4 onward? In other words, have you believed that there is always some true left arm abduction from the beginning of p4 in all elite golfers?" My thinking has evolved. I do not believe that there is any significant left arm abduction between P4 and P5, and that significant left arm abduction only begins after P5, being small in amount between P5 and P5.5, and then becoming much larger in amount between P5.5 and impact. Look at Jamie Sadlowski's hand arc path. Between point 1 (P4) and point 2 (P5) there is virtually no left arm abduction, and the hand arc path is "straightish" but angled away from the target because his left arm moves from being angled at 12 o'clock at P4 to being angled at 9 o'clock by P5 as his torso rotates counterclockwise and his left arm depresses due to independent left arm motion happening in his left shoulder socket. Between point 2 (P5) and point 3 (P5.5) a small amount of left arm abduction must happen to move the hands targetwards to a small degree so that the hands can become located vertically under point 1 by P5.5, and therefore the same distance from the target as point 1 was at P4. Most of the left arm abduction phenomenon happens between P5.5 (point 3) and impact (point 4) so that the hand arc path can be nearly parallel to the ground during the later downswing when PA#2 and then PA#3 is released. You asked-: "Here is a comparison between Jon Rahm and Adam Scott. Would it be fair to say there is a slower phase of left arm abduction from p4 to p5.5, and a faster phase of left arm abduction from p5.5 to p6.5?" There should be no left arm abduction between P4 and P5, and only a small amount between P5 and P5.5, and a much larger amount between P5.5 and impact. You asked-: "Do you believe that JR has a faster phase of left abduction than AS from p4 to p5.5?"
No. However, JR has a faster phase of left arm depression than AS between P4 and P5.5.
You asked-: "Do you see any part of AS's swing where his shoulders and left arm are moving at the same rotational speed between p4 and p5.5? Only between P4 and P5. After P5 the left arm is moving faster than his upper torso. Jeff.
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Post by utahgolfer on Mar 25, 2020 16:30:13 GMT -5
Jeff,
Here you state: Between point 1 (P4) and point 2 (P5) there is virtually no left arm abduction, and the hand arc path is "straightish" but angled away from the target because his left arm moves from being angled at 12 o'clock at P4 to being angled at 9 o'clock by P5 as his torso rotates counterclockwise and his left arm depresses due to independent left arm motion happening in his left shoulder socket.
Do you actually mean left scapular depression that lowers the left scapula and therefore lowers the left shoulder and accompanying left arm between p4 and p5? What do you mean by left arm depression?
What do you mean by independent left arm motion happening in his left shoulder socket? Again, do you mean scapular depression is causing this?
I'm still not entirely sure why you disagreed with my speculations, other than I wasn't clear enough on what you call left arm depression at p4, that we differed slightly on the PP#4 dialogue, and that I said that true left arm abduction started at p5.5 instead of p5.
But, as long as I'm learning, I'm good.
UG
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Post by imperfectgolfer on Mar 25, 2020 19:26:49 GMT -5
Jeff, Here you state: Between point 1 (P4) and point 2 (P5) there is virtually no left arm abduction, and the hand arc path is "straightish" but angled away from the target because his left arm moves from being angled at 12 o'clock at P4 to being angled at 9 o'clock by P5 as his torso rotates counterclockwise and his left arm depresses due to independent left arm motion happening in his left shoulder socket. Do you actually mean left scapular depression that lowers the left scapula and therefore lowers the left shoulder and accompanying left arm between p4 and p5? What do you mean by left arm depression? What do you mean by independent left arm motion happening in his left shoulder socket? Again, do you mean scapular depression is causing this?I'm still not entirely sure why you disagreed with my speculations, other than I wasn't clear enough on what you call left arm depression at p4, that we differed slightly on the PP#4 dialogue, and that I said that true left arm abduction started at p5.5 instead of p5. But, as long as I'm learning, I'm good. UG No - I am not talking about scapular depression as causing left arm depression (lowering), and I am referring to the angle of the left humerus in the left shoulder socket as depicted in the following web page where they talk of flexion and abduction-adduction. www.acefitness.org/fitness-certifications/ace-answers/exam-preparation-blog/3535/muscles-that-move-the-arm/When I use the term left arm abduction/adduction, I am only referring to what is called horizontal abduction/adduction motions in that page. When I talk about left arm elevation/depression, then I am referring to elevating (or lowering) the left arm in either the coronal plane (which is referred to as abduction-adduction in that page) or the sagittal plane (which is referred to as flexion in that page) or in any plane that is intermediate between the coronal or sagittal plane.
Jeff.
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Post by utahgolfer on Mar 25, 2020 20:00:26 GMT -5
Okay, that makes sense.
Another observation on this topic is that the backswing and downswing are similar in terms of the sequence of independent left arm motion.
During the backswing, there is more shoulder-based motion of the left humerus during the first half of the backswing, and more independent left humerus motion during the second half of the backswing.
During the downswing, there is more shoulder-based motion of the left humerus during the first half of the downswing, and more independent left humerus motion during the second half of the downswing.
So, the sequence is: dependent, independent, dependent, and independent.
UG
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Post by utahgolfer on Mar 25, 2020 23:20:53 GMT -5
Jeff, I assume this is a unique example of the downward (extension) of the left humerus during early downswing as you indicated. It's also interesting to see his very strong grip and his no left forearm supination into impact.
UG
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Post by imperfectgolfer on Mar 26, 2020 10:50:17 GMT -5
Okay, that makes sense. Another observation on this topic is that the backswing and downswing are similar in terms of the sequence of independent left arm motion. During the backswing, there is more shoulder-based motion of the left humerus during the first half of the backswing, and more independent left humerus motion during the second half of the backswing. During the downswing, there is more shoulder-based motion of the left humerus during the first half of the downswing, and more independent left humerus motion during the second half of the downswing. So, the sequence is: dependent, independent, dependent, and independent. UG UG, I have no clear understanding of what you saying. I can understand how it is possible to have a shoulder-based motion of the left humerus in the early downswing if you mean that the left shoulder socket's motion (due to an upper torso rotation) is pulling the left humerus along with it, with the left shoulder socket leading the way - because a pulled object can follow a path directed by the pulling agent (like a toy car can follow a child pulling the car along with an attached string). However, I cannot understand how one can have a shoulder-based motion of the left humerus in the backswing if the left humerus is moving further away from the target than the left shoulder with the left humerus leading. Are you implying that the motion of the left shoulder socket is pushing the left humerus backwards? If my guess is correct, then it makes no sense to me because the path of the left arm cannot be determined by "something" that simply pushes the left humeral head backwards.Whether one uses an one-piece takeaway, or a right forearm takeaway, the directional motion of the left humerus cannot be dictated by the movement of the left shoulder socket in a clockwise direction.
Jeff.
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Post by imperfectgolfer on Mar 26, 2020 11:15:49 GMT -5
Jeff, I assume this is a unique example of the downward (extension) of the left humerus during early downswing as you indicated. It's also interesting to see his very strong grip and his no left forearm supination into impact. UG I can see nothing unique about this golfer other than the fact that he has a lot of right lateral bend (more than Dustin Johnson) and he "crunches" his right side to an exaggerated degree - as seen at his P5.5 position (if the video is stopped at the 1:12 minute time point). I also don't understand why you are using the phrase "downward extension of the left humerus". It is true that he bends his left arm at P4 and that he then straightens it between P4 and P5.5 - but I presume that you are not referring to that fact.
When I talk about the release of PA#4 between P4 and P5.5, I talk about the directional motion of the left arm (relative to the left shoulder socket) as being divided into two components - a horizontal abduction component and a left arm depression (lowering) component with the latter component being most prominent between P4 and P5.5. Consider Dustin Johnson's early-mid downswing action. Image 1 is at P4, image 2 is at P5 and image 3 is at P5.5.
The downward motion of the left humerus (relative to the left shoulder socket) can be determined by likening it to a clock (with the center of the clock being the left shoulder socket and the left arm being the hour arm). At P4 the left arm is at 12 o'clock, at P5 it is at 9 o'clock, and at P5.5 it is at 7:30 o'clock. Those changes in the left arm's angular motion are happening in the left arm's depression plane without there being any significant change in the left arm's angle in the horizontal left arm adduction-abduction plane.
Jeff.
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Post by utahgolfer on Mar 26, 2020 17:36:53 GMT -5
First of two posts above: It is simple. During the first part of backswing, the left arm piggybacks and moves more in sync with the left shoulder turn, whereas during the second half of the backswing, the left arm moves more independently and at a faster, more noticeable rate of motion relative to the left shoulder turn. The downswing follows this same pattern. During the first part of downswing, the left arm piggybacks and moves more in sync with the left shoulder turn, whereas during the second half of the downswing, the left arm moves at a faster, more noticeable rate of motion relative to the left shoulder turn. Second of two posts above: I've only heard of depression when referring to the scapula and only extension when referring to the humerus. If the arm is raised in the sagittal plane and extended, the arm is lowered downward; if the hanging arm is flexed, the arm is raised upward (see illustration). Abduction is moving the hanging arm away from the midline in the frontal plane whereas horizontal abduction is moving the horizontal arm away from the midline while moving level with the ground. The golf swing is performed on an inclined plane and the torso is rotated at the same time. How can your current descriptors apply to this? Based on which plane you choose, the left arm in the downswing could be called extension or abduction. The humerus simply rotates within the joint capsule, so how can it be called one thing from p4 to p5 and the another thing from p5 to p7? I also don't see how anything can be called "horizontal" since the swing is performed on an inclined plane, and is not level with the ground. Based on how I currently see it, I would drop the term abduction and simply describe independent left humerus motion as either more vertical/more downward or more horizontal/more level. Abduction or adduction may sound more technical, but I'm not sure how this is universally precise when the swing is inclined and rotating. Thus, from p1 to p2 the left arm moves more horizontal/level and more in sync with the left shoulder turn, and from p3 to p4 the left arm moves more vertical/upward and more independent of the left shoulder turn. From p4 to p5, the left arm moves more vertical/downward and more in sync with the left shoulder turn, and from p5 to p7 the left arm moves move horizontal/level and more independent of the left shoulder turn. The challenge is to describe why the left arm is moving downward from p4 to p5 and to describe it as independent or dependent left arm motion. For example, is the left arm moving downward because of shoulder/torso rotation or right lateral bend (dependent motion) or because of independent left arm motion? Likewise, from p5 to p7, is the left arm moving more horizontal because of shoulder/torso rotation (dependent motion) or because of independent left arm motion? Also, how is it best to instruct golfers? We would probably never use the term left arm adduction or abduction. The backswing or downswing could be off plane due to an improper shoulder/torso turn angle or improper independent left arm motion or both (among other problems). It would be important to discuss this in terms the golfer can understand. When teaching about the initial downswing, most players don't have enough vertical rotation of the shoulders (the shoulders/torso rotate too horizontal). This more than anything else causes the left arm to initially move too horizontal and not downward enough (due to dependent left arm motion). Once this is fixed, the player can work on some independent downward left arm motion, although the shoulder/torso rotation is still producing some simultaneous (dependent) downward motion of the left arm. To do this, the player could work on a bit more independent left arm downward motion as a result of some simultaneous independent horizontal right arm motion (pitched right elbow move). But, here the player may incorrectly try to get more downward left arm motion by using early right lateral bend instead of a proper shoulder/turn or independent left arm motion. The player would need to be taught the difference and how to do this correctly. Another point of instruction would be to teach the player the difference between independent and dependent scapula motion, and how independent micro-movements of the scapula can influence the golf swing. The above example of Ryan Fox is unique because he looks to have a lot of quick independent downward motion of the left arm during the transition, whereas most players seem to spread this out and perform it more gradually (and much less noticeably). UG
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