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Post by dubiousgolfer on Jul 12, 2021 18:21:43 GMT -5
Dr Mann
Here is my confusion:
I am assuming that the hands/palms on the grip do not change their relationship with each other although, as you've proved, the forearms can change their relationship (ie. the lead forearm supinating while the trail forearm retaining supination from P6-P7 as in JT's images).
Therefore wherever the GFLW is facing at impact there should be no relative change in the direction the trail palm is facing (ie. as per the original relative hand positions on the grip at address).
If the GFLW rotates counterclockwise so must the trail palm (am I correct?).
If a GFLW is rotating 'counterclockwise' I cannot understand how the trail palm can have a passive circumduction movement (ulnar deviation and flexion) that rotates 'clockwise'.
DG
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Post by imperfectgolfer on Jul 12, 2021 19:19:22 GMT -5
Dr Mann Here is my confusion: I am assuming that the hands/palms on the grip do not change their relationship with each other although, as you've proved, the forearms can change their relationship (ie. the lead forearm supinating while the trail forearm retaining supination from P6-P7 as in JT's images). Therefore wherever the GFLW is facing at impact there should be no relative change in the direction the trail palm is facing (ie. as per the original relative hand positions on the grip at address). If the GFLW rotates counterclockwise so must the trail palm (am I correct?). If a GFLW is rotating 'counterclockwise' I cannot understand how the trail palm can have a passive circumduction movement (ulnar deviation and flexion) that rotates 'clockwise'. DG To better understand this complex issue, let's examine the golf swings of two different golfers. Capture images of Justin Thomas driver golf swing action. Justin Thomas uses a weak lead hand grip and a strong ("side-under") trail hand grip.
Image 1 is at P6.5 and image 2 is at P7 and image 3 is at P7.5.
Because he uses a weak lead hand grip, he needs to use a certain amount of lead forearm supinatory motion to complete his PA#3 release action that is happening between P6.5 => P7 - note that the back of his lead hand has rotated counterclockwise by a finite amount between image 1 and image 2. I agree that his trail palm must rotate counterclockwise by a finite amount during his PA#3 release action.
There are two factors that can cause a counterclockwise rotation of his trail palm - a decrease in his amount of trail forearm supination and a straightening of the trail wrist without any clockwise trail wrist circumductory roll motion. You can see that his trail forearm looks fractionally less supinated in image 2 compared to image 1, which indicates that his trail forearm is rolling counterclockwise by a small amount. You can see that his trail wrist is straightening between image 1 => image 2, but note that it not yet moving much more towards ulnar deviation, so there is no significant amount of clockwise trail wrist circumductory roll motion happening between P6.5 => P7, and that combination should contribute to a counterclockwise roll motion of his trail palm.
Note that his trail wrist looks more ulnar-deviated at P7.5 (image 3) and one can naturally expect that he has a finite amount of clockwise trail wrist circumductory roll motion happening between P7 => P7.5, which combined with an absence of any significant degree of trail wrist pronation, allows him to keep his trail palm more under the club handle between P7 => P7.5. Capture images of Patrick Rodgers driver golf swing action. Patrick Rodgers uses a weak lead hand grip and weak ("on-top") trail hand grip. Image 1 is at P6.5, image 2 is at P7 and image 3 is at P7.5. Note that PR uses a PA#3 release action between P6.5 => P7 in order to get the back of his lead wrist to face the target at impact. So, his trail palm must rotate counterclockwise during his PA#3 release time period. Note that his trail forearm is less supinated at P6.5 (compared to Justin Thomas at P6.5) and it looks neutral at impact, which means that his trail forearm must be rotating counterclockwise by a finite amount between P6.5 => P7. Also, note that he is straightening his trail wrist to a small degree between P6.5 => P7 without it moving towards ulnar deviation and that should produce a counterclockwise rotation of his trail palm because there is no offsetting clockwise trail wrist circumductory roll motion happening between P6.5 => P7. Between P7 => P7.5 it looks like he is pronating his trail forearm by a small amount, which allows his trail palm to continue to rotate counterclockwise by the small amount needed to keep his trail palm behind the club handle. Also, note that he maintains a small degree of radial deviation of his trail wrist between P7 => P7.5 so that he does not likely have any clockwise trail wrist circumductory roll motion happening between P7 => P7.5 (as seen in Justin Thomas' early followthrough action) and that allows him to keep his trail palm behind the club handle, and not under the club handle (as seen in Justin Thomas' early followthrough action). Jeff.
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Post by dubiousgolfer on Jul 12, 2021 19:42:40 GMT -5
Dr Mann Your explanation makes a lot more sense to me . In my search for an explanation I was by chance looking at another video of a golfer from a top view (see below) and I noticed the GFLW was moving inside and upward from P6.5 -P7 as his left forearm was supinating. Does this movement inside (see images below where I've drawn a white line as reference) also assist in squaring the clubface and is it associated with the upper body pivot? DG
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Post by imperfectgolfer on Jul 12, 2021 19:50:48 GMT -5
Dr Mann Your explanation makes a lot more sense to me . In my search for an explanation I was by chance looking at another video of a golfer from a top view (see below) and I noticed the GFLW was moving inside and upward from P6.5 -P7 as his left forearm was supinating. Does this movement inside (see images below where I've drawn a white line as reference) also assist in squaring the clubface and is it associated with the upper body pivot? DG I cannot understand why any upward movement of the left hand will help square the clubface. However, if his lead humerus is rotating counterclockwise in the direction of external rotation while his lead shoulder moves upwards-and-inside and while his lead hand moves upwards, then it could definitely contribute to the counterclockwise rotation of the GFLW during a PA#3 release action. Jeff.
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Post by dubiousgolfer on Jul 12, 2021 21:02:45 GMT -5
Many thanks again Dr Mann
DG
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Post by dubiousgolfer on Jul 13, 2021 10:37:53 GMT -5
Dr Mann
If there is no actual circumduction clockwise movement of the trail wrist happening between P6-P7 in JT's swing , but his trail wrist is ulnar deviating and flexing P7-P7.5 (which should signify a tendency for clockwise rotation) , doesn't this mean that the trail wrist is actually biomechanically opposing any counterclockwise rotation of the GFLW through impact?
Is this what can assist a DH hand release action?
DG
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Post by imperfectgolfer on Jul 13, 2021 13:28:40 GMT -5
Dr Mann If there is no actual circumduction clockwise movement of the trail wrist happening between P6-P7 in JT's swing , but his trail wrist is ulnar deviating and flexing P7-P7.5 (which should signify a tendency for clockwise rotation) , doesn't this mean that the trail wrist is actually biomechanically opposing any counterclockwise rotation of the GFLW through impact? Is this what can assist a DH hand release action? DG I do not think that the trail wrist is resisting any clockwise rotation of the trail palm that could happen if the trail wrist is undergoing a circumductory clockwise roll motion due to the combination of trail wrist flexion + ulnar deviation. I simply cannot quantify how much the trail wrist is moving towards ulnar deviation between P6 => P7 versus between P7 => P7.4 - other to state that more clockwise rotation is probably happening in a golfer who has an "under" trail hand grip rather than an "on-top" trail hand grip. It is also dependent on how much the trail wrist straightens between P7 => P7.4. If there is negligible trail wrist straightening happening between P7 => P7.4, then there cannot be a significant amount of clockwise circumductory roll motion happening during that same time period. Jeff.
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Post by dubiousgolfer on Jul 13, 2021 19:27:08 GMT -5
Dr Mann
Apologies for these questions but you mentioned the following in a previous post:
"There are two factors that can cause a counterclockwise rotation of his trail palm - a decrease in his amount of trail forearm supination and a straightening of the trail wrist without any clockwise trail wrist circumductory roll motion."
I cannot understand how a straightening of the trail wrist can cause a counterclockwise rotation of the trail palm. A straightening of the trail wrist is just movement from extension to flexion direction.
On looking at that top view of the golfer in my previous post doesn't it seem that there is a progressive change in the orientation of the scapula spines in the late downswing. Could the protraction of the trail scapula help rotate the whole right arm (while retaining the supination of the forearm) to complement supination of the left arm/forearm?
DG
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Post by imperfectgolfer on Jul 13, 2021 22:05:17 GMT -5
Dr Mann Apologies for these questions but you mentioned the following in a previous post: "There are two factors that can cause a counterclockwise rotation of his trail palm - a decrease in his amount of trail forearm supination and a straightening of the trail wrist without any clockwise trail wrist circumductory roll motion." I cannot understand how a straightening of the trail wrist can cause a counterclockwise rotation of the trail palm. A straightening of the trail wrist is just movement from extension to flexion direction. On looking at that top view of the golfer in my previous post doesn't it seem that there is a progressive change in the orientation of the scapula spines in the late downswing. Could the protraction of the trail scapula help rotate the whole right arm (while retaining the supination of the forearm) to complement supination of the left arm/forearm? DG DG, You stated-: " I cannot understand how a straightening of the trail wrist can cause a counterclockwise rotation of the trail palm. A straightening of the trail wrist is just movement from extension to flexion direction." Look at these capture images of Patrick Rodgers release. Note that his trail forearm is supinated in image 1, which will allow the trail palm to face the back of the club handle, which is angled about 45 degrees to the right. In other words, the trail wrist's plane of extension => flexion is angled to the right so that it can be roughly perpendicular to the club handle. Then, in image 2 the club handle is nearly perpendicular to the ball-target line. Between image 1 => image 2 his trail wrist is straightening while moving towards radial deviation and that motion is combined with a small degree of counterclockwise rotation of the trail forearm. The combined motion allows the trail palm to move from being angled 45 degrees to the right to being more vertically oriented so that it remains behind the club handle. Try and mimic PR's trail wrist position in image 1 - so that your trail palm is angled ~45 degrees to the right. Then, straighten your trail wrist while allowing it to move towards radial deviation. You should note that your trail palm is becoming vertical, which means that there is an element of counterclockwise rotation of the trail palm happening during the trail wrist straightening action. Protraction of the trail scapula in that "top-view" golfer combined with a lot of counterclockwise of the upper torso makes it easier for the whole trail arm to rotate internally so that the trail forearm can more easily change its angles.
Note that his trail forearm is perpendicular to the ball-target line at P6 (image 1) and then angled about 45 degrees to the ball-target line at impact (image 3) and then angled nearly parallel to the ball-target line at P7.5 (image 4). That allows his trail palm to remain behind the club handle while the club handle changes its angular orientation by ~150 degrees between image 1 => image 4.
Note that he maintains an intact LFFW between image 1 => image 4, and that his entire LFFW is rotating ~150 degrees, and note that he can keep his trail palm parallel to his intact LFFW all the way between P6 => P7.5. That is biomechanically possible because he does not "run-out-of-trail arm", which is made more biomechanically possible because his trail scapula is protracted, because his upper torso rotates a lot counterclockwise and because his trail shoulder socket moves targetwards under his chin.
Jeff.
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Post by imperfectgolfer on Jul 13, 2021 22:41:07 GMT -5
I am now inclined to think that internal rotation of the trail humerus does have a clubface closing effect if the trail humerus changes it angles during the process of internal rotation. I previously argued that if the one kept the trail humerus vertical and then rotated it 90 degrees counterclockwise while keeping the trail forearm supinated, that it would not have a clubface closing effect. That claim would apply if the trail humerus remained stationary. However, look at these capture images of the "top view" golfer. Note that his trail elbow is progressively moving closer to the target between image 1 => image 4 as his trail upper forearm moves from being vertical and perpendicular to the ball-target line at P6, to becoming nearly parallel to the ball-target line at P7.5. During that time period, his trail humerus is rotating internally, while it is simultaneously changing is angular orientation, and that combination may allow the trail palm to rotate counterclockwise secondary to the rotary motion of the trail upper arm, and not solely due to counterclockwise rotation of the trail forearm - note that the upper trail forearm looks more rotated counterclockwise in image 4 compared to image 1.
Jeff.
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Post by dubiousgolfer on Jul 14, 2021 7:43:02 GMT -5
Dr Mann
Your last post seems a more plausible explanation of the biomechanics .
You mentioned previously:
"Try and mimic PR's trail wrist position in image 1 - so that your trail palm is angled ~45 degrees to the right. Then, straighten your trail wrist while allowing it to move towards radial deviation. You should note that your trail palm is becoming vertical, which means that there is an element of counterclockwise rotation of the trail palm happening during the trail wrist straightening action."
I found it very difficult to allow my trail wrist to straighten and move towards radial deviation . It was more natural for me to allow it to passively straighten and move into ulnar deviation because the dynamic weight (you can all it centrifugal force) of the club is becoming very large. But flexion and ulnar deviation of the trail wrist obviously causes a clockwise rotation of the palm/fingers which is why I thought some other biomechanics must be involved to still allow the trail palm to complement the counterclockwise rotation of the intact LFFW.
So I wondered if the trail humerus internal rotation coupled with the protraction of the trail scapula could still allow the trail palm to rotate (trail forearm still in supination) with the intact LFFW (while still performing a clockwise circumduction). I then wondered whether this passive clockwise circumduction movement by the trail wrist could help impede the counterclockwise movement of the LFFW to reduce the ROC and assist in a 'DH- hand release action'.
DG
PS. I was viewing some videos of Jon Sinclair trying to explain the biomechanics of dual supination of the forearms but it was very vague and just didn't make any sense to me at all. See the 2nd video below from 22:54 - 30:23
Apparently the TPI database that Jon Sinclair uses does not have any measured data for internal rotation of the trail humerus, scapula motions or grip strength information.
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Post by imperfectgolfer on Jul 14, 2021 10:39:57 GMT -5
DG,
You wrote-: "I was viewing some videos of Jon Sinclair trying to explain the biomechanics of dual supination of the forearms but it was very vague and just didn't make any sense to me at all. See the 2nd video below from 22:54 - 30:23."
I don't know why it makes no sense to you.
Jeff.
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Post by dubiousgolfer on Jul 14, 2021 11:00:01 GMT -5
DG, You wrote-: " I was viewing some videos of Jon Sinclair trying to explain the biomechanics of dual supination of the forearms but it was very vague and just didn't make any sense to me at all. See the 2nd video below from 22:54 - 30:23." I don't know why it makes no sense to you. Jeff. Dr Mann Actually , look at the avatar animation in the 1st video from 0:21 - 0:47 . I think Jon Sinclair is stating that the hands are twisting on the grip in opposite directions to make dual supination happen (ie. left hand twisting counterclockwise while right hand twisting clockwise). I think these actions will make the elbows move closer together and that will cause effective supination of both forearms. Imho, that active twisting on the grip seems unnatural to me. DG
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Post by imperfectgolfer on Jul 14, 2021 11:45:59 GMT -5
That dual forearm supination seen in the avatar that is happening in the mid-dowswing only happens in pro golfers who use an "early lead forearm supination + lead wrist bowing" maneuver eg. Gary Woodland.
Note that GW is supinating both forearms in image 4.
Pro golfers who use an intact LFFW/GFLW technique only start to supinate their lead forearm after P6 and dual forearm supination exists between P6 => P6.7+ if the trail forearm becomes neutral after P6.7 in pro golfers who adopt an "on-top" or "side-cover" trail hand grip, and dual forearm supination exists all the way between P6 => P7 if the trail grip is "side-on" or "under".
Jeff.
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Post by dubiousgolfer on Jul 14, 2021 16:50:16 GMT -5
Many thanks for the explanation Dr Mann
DG
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