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Post by dubiousgolfer on Mar 26, 2020 18:59:48 GMT -5
I suspect one could use diagonal left arm abduction or adduction (easier to visualise). DG PS. On reflection ,maybe not because the above wouldn't apply to the left arm movement in the golf downswing.
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Post by syllogist on Mar 27, 2020 7:06:26 GMT -5
Hi UG, You wrote: "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). " Take a look at Athletic Motion's presentation about forward bend: www.youtube.com/watch?v=uA6G7jl4pLIThe presentation shows a tour pro's 7-iron swing where the degree to which the spine is tilted toward the target line is consistent within a small range around 40 degrees. I'm not really interested in how forward bend turns into lateral bend through the backswing, becomes forward bend through the downswing, and becomes lateral bend through impact and beyond. This is rather obvious when one rotates the torso with approximately the same forward inclination. It is also obvious that there are pros who both increase and decrease forward bend during the downswing. Perhaps the consistency of maintaining forward bend of an "ideal" amount, which may slightly vary depending on the length of the club, during torso rotation may address the issue of a more consistent and ideal swing path given rotation. S
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Post by imperfectgolfer on Mar 27, 2020 9:26:23 GMT -5
UG,
You wrote-: "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."
I don't see that happening in many gofers who get their left arm across their shoulder turn angle, and who time their left arm motion so that it is perfectly synchronised with their upper torso rotation. They stop moving their left arm up-plane when their upper torso rotation stops. I can see more independent left arm motions in the late backswing in golfers who get their left arm very steep at P4, or in the early backswing if they start their takeaway with an independent arm action that is significantly faster than any upper torso rotation.
Regarding your use of the term "extension" it does make more sense than my use of the term "depression". However, I think that it would confuse golfers if I used the term "flexion" to refer to left arm elevating motions and "extension" when I refer to left arm lowering motions. I think that I will stick to the terms "elevating" and "lowering" to describe left arm motions in the vertical plane. I still prefer the term "horizontal adduction/abduction" even though a golfer's upper torso is not parallel to the ground during many moments of the downswing - because I use as my reference a line drawn between the shoulder sockets as the reference line for assessing degrees of left arm adduction => abduction.
Jeff.
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Post by utahgolfer on Mar 27, 2020 16:40:38 GMT -5
Jeff, okay show me any PGA pro who doesn’t have more independent motion of the humerus during the second half of the backswing than the first half.
I’ll bet you a virtual dollar on this one. Haha.
And, I’d bet you can’t find a PGA golfer who doesn’t have more independent humerus motion during the second half of the downswing than the first half.
UG
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Post by imperfectgolfer on Mar 27, 2020 17:50:05 GMT -5
Jeff, okay show me any PGA pro who doesn’t have more independent motion of the humerus during the second half of the backswing than the first half. I’ll bet you a virtual dollar on this one. Haha. And, I’d bet you can’t find a PGA golfer who doesn’t have more independent humerus motion during the second half of the downswing than the first half. UG Here is a typical pro golfer's backswing action. I think that AS is still rotating his upper torso clockwise while his left arm moves around his body during the 2nd half of his backswing action. I don't think that he is moving his left arm in some independent manner that is not reasonably synchronised with the rotation of his upper torso. Jeff.
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Post by utahgolfer on Mar 27, 2020 19:14:30 GMT -5
Jeff, the shoulders may move during the entire backswing, but the left humerus may be moving dependently or independently. From p1 to p2.5, the left humerus moves mostly because the shoulders are rotating (dependent motion), and this moves the humerus. From p2.5 to p4, the shoulders could be turning the the entire time which still moves the humerus some, but here the humerus is actually rotating more inside the joint capsule (independent motion).
All I am saying is there is more independent left arm motion of the left humerus from p2.5 to p4 in all players, than there is from p1 to p2.5, with no exceptions (on the PGA tour).
And, the same pattern occurs during the downswing, and I believe this is an important concept to know and teach.
UG
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Post by imperfectgolfer on Mar 27, 2020 23:09:47 GMT -5
Jeff, the shoulders may move during the entire backswing, but the left humerus may be moving dependently or independently. From p1 to p2.5, the left humerus moves mostly because the shoulders are rotating (dependent motion), and this moves the humerus. From p2.5 to p4, the shoulders could be turning the the entire time which still moves the humerus some, but here the humerus is actually rotating more inside the joint capsule (independent motion). All I am saying is there is more independent left arm motion of the left humerus from p2.5 to p4 in all players, than there is from p1 to p2.5, with no exceptions (on the PGA tour). And, the same pattern occurs during the downswing, and I believe this is an important concept to know and teach. UG We will simply have to accept that we disagree on this issue. I think that there is as much independent motion of the left humerus between P2.5 and P4 as there is between P4 and P5.5 in Adam Scott's golf swing action. Jeff.
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Post by utahgolfer on Mar 27, 2020 23:57:52 GMT -5
Okay, but I'm not comparing the backswing to the downswing. I'm only comparing the first half of the backswing to the second half of the backswing, and the first half of the downswing to the second half of the downswing. UG
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Post by dubiousgolfer on Mar 28, 2020 12:11:12 GMT -5
Dr Mann /UG Have you ever seen this article before (just discovered it)? www.sciencedirect.com/science/article/pii/S2095254614001276If I've interpreted this correctly , clubhead speed increased when the time difference is small between the initial 'firing' of the 'left latissimus dorsi' and then firing of 'right pectoralis major'. The other interesting result showed a positive correlation with clubhead speed the greater the time difference between the 'maximum left foot GRF' and impact. I found the 'Discussion' a bit too confusing to understand properly but maybe the 2 of you might fare better. I tried to summarise my interpretation below but it doesn't make sense 1. The left 'lats dorsi' is the only connecting back muscle that links to 'upper arm/spine/pelvis' which can be used to powerfully rotate the trunk via a powerful twist of lower limb movement. 2. There is no 'peak left foot' force in the initial downswing because the left hip could not achieve the twisting power to stretch the 'left lats dorsi' and drag the upper arm and club downward. 3. That there is some correlation between the EMG firing of the 'left lats dorsi' and the timing of the peaking of the left foot GRF (although they didn't show any evidence to prove that in the article). 4. That for enhanced clubhead speed the 'left lats dorsi' must fire first before the 'pectoralis major' (where clubhead speed increases the shorter the interval between their 'firing' -as mentioned earlier above) So what is bringing the left arm down from P4-P5 ? Point 2 suggests its not the 'left lats dorsi' , while point 4 suggests it cannot be the 'pectoralis major' because it fires after the 'left lats dorsi'. It doesn't make sense to me at all!!! DG
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Post by imperfectgolfer on Mar 28, 2020 13:35:00 GMT -5
Dr Mann /UG Have you ever seen this article before (just discovered it)? www.sciencedirect.com/science/article/pii/S2095254614001276If I've interpreted this correctly , clubhead speed increased when the time difference is small between the initial 'firing' of the 'left latissimus dorsi' and then firing of 'right pectoralis major'. The other interesting result showed a positive correlation with clubhead speed the greater the time difference between the 'maximum left foot GRF' and impact. I found the 'Discussion' a bit too confusing to understand properly but maybe the 2 of you might fare better. I tried to summarise my interpretation below but it doesn't make sense 1. The left 'lats dorsi' is the only connecting back muscle that links to 'upper arm/spine/pelvis' which can be used to powerfully rotate the trunk via a powerful twist of lower limb movement. 2. There is no 'peak left foot' force in the initial downswing because the left hip could not achieve the twisting power to stretch the 'left lats dorsi' and drag the upper arm and club downward. 3. That there is some correlation between the EMG firing of the 'left lats dorsi' and the timing of the peaking of the left foot GRF (although they didn't show any evidence to prove that in the article). 4. That for enhanced clubhead speed the 'left lats dorsi' must fire first before the 'pectoralis major' (where clubhead speed increases the shorter the interval between their 'firing' -as mentioned earlier above) So what is bringing the left arm down from P4-P5 ? Point 2 suggests its not the 'left lats dorsi' , while point 4 suggests it cannot be the 'pectoralis major' because it fires after the 'left lats dorsi'. It doesn't make sense to me at all!!! DG I think that the golf researchers are TGM-illiterate and I think that their study is worthless! Jeff.
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Post by dubiousgolfer on Apr 16, 2020 9:05:57 GMT -5
Dr Mann Just reading this thread again but wondering why you thought the following regarding this golfer below: 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 armHow can a lead humerus get trapped under the lead shoulder socket? DG
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Post by imperfectgolfer on Apr 16, 2020 11:00:07 GMT -5
Dr Mann Just reading this thread again but wondering why you thought the following regarding this golfer below: 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 armHow can a lead humerus get trapped under the lead shoulder socket? DG I don't really mean that the lead humerus is physically trapped, and I only mean that the proximal end of the lead humerus is positioned below the lead shoulder socket at P4. Then, when the lead shoulder moves targetwards between P4 and P5.5 as the upper torso rotates around the thoracic spine, it allows the lead arm to be directed more easily downwards (rather than excessively outwards and OTT). A key biomechanical phenomenon that must happen is that a golfer must maintain his spinal bend inclination angle between P4 and P5, so that the lead shoulder stays low as it moves targetwards. If a golfer "stands-up" due to a loss of spinal bend inclination angle between P4 and P5, then the lead shoulder will be moving upwards while it moves targetwards and that will more likely predispose to an OTT move. Jeff.
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Post by dubiousgolfer on Apr 16, 2020 11:28:24 GMT -5
Apologies - this post below crossed with your reply above (the above might actually answer my question below about OTT) Dr Mann When reviewing your critical review of Tyler Ferrell you mentioned the below regarding DJ's swing from P4-P5 What causes his hands to move very fastbetween P4 and P5? I think that a significant factor is the fastspeed of motion of his left shoulder socket in a targetwards direction that pulls the left humeral head in the same direction. If the left humeral headmoves targetwards very fast between P4 and P5, it must exert a considerabledownward pull on the left arm because his left arm is angled upwards to the12 o'clock position at his P4 position. However, note that Dustin Johnsonmaintains an unchanged degree of right elbow bend between P4 and P5 and hisright elbow is dropping in a groundwards direction very fast due to anactive right arm adduction maneuver. I can readily imagine that his rightpalm, which is moving downwards very fast between P4 and P5, could beapplying a certain amount of push-pressure against PP#1 (which is locatedover the base of his left thumb), thereby synergistically helping him tomove his left hand (which is pulling the club handle) in a groundwardsdirection at an optimallyfast speed.When you state 'targetwards' direction of left shoulder socket , do you really mean CCW rotation of the socket due to upper torso rotation, where the upper left arm is abducted in a plane more perpendicular to the axis of torso rotation? So when we see DJ's left arm from a face on view , its movement from P4-P5 can theoretically be attributed into 3 components: Component 1 : 'Horizontal Abduction' caused by the upper body pivot in a plane perpendicular to the axis of upper torso rotation Component 2 : 'Horizontal Abduction/Extension' caused by left shoulder girdle muscles Component 3 : 'Humerus Adduction' caused by right shoulder girdle muscles Wouldn't component 1 be similar to a 'Horizontal Adduction' move by the right arm which would cause an OTT swing path? DG
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Post by imperfectgolfer on Apr 16, 2020 12:45:29 GMT -5
DG,
You asked-: "Wouldn't component 1 be similar to a 'Horizontal Adduction' move by the right arm which would cause an OTT swing path?".
No!
Component 1 (horizontal abduction motion of the left arm) will be more downwards (rather than outwards in an OTT manner) if the golfer maintains his spinal bend inclination angle and where the upper left arm is abducted in a plane more perpendicular to the axis of torso rotation; and the right arm adduction maneuver moves the right hand more downwards if the right elbow is pitching, and not punching (which can move the right hand more outwards).
Jeff.
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