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Post by imperfectgolfer on Oct 20, 2012 13:37:42 GMT -5
Consider these Phantom camera videos of John Oda's swing. Those slow motion videos clearly show the hand action through impact, and clearly show that a golfer (who uses a neutral or slightly strong left hand grip) uses PA#3 to close the clubface prior to impact (in the time period between P6.5 and P7) - and that the biomechanical basis is a left forearm supination action synergistically assisted by a right forearm paddlewheeling action. Image 1 shows JO at addresss - he has a slightly strong left hand grip which means that his clubface will be slightly closed to the back of his left hand. Note that his left forearm is nearly neutral and only minimally pronated at address. Image 2 shows him at P5.5 where the back of his FLW is parallel to the inclined plane, and the clubface must still be slightly closed to the back of his FLW. Image 3 shows him at P6 - note that the back of his FLW is parallel to the ball-target line. Image 4 shows him at impact, and note that the back of his FLW has rotated ~90 degrees. When does that happen? One clearly see when it happens in these close-up views of his hands. Note that image 1 is at the P6.5 position - and his FLW is angled away from the target (and still nearly parallel to the ball-target line). One can clearly see how much his left lower forearm/back of his left hand rotates between P6.5 and P7.1 and that it is primarily due to a left forearm supination motion, and this represents the release of PA#3. Tapio's idea that a golfer primarily squares the clubface in the late downswing by a torso rotation motion, and KM's idea of early supination to square the clubface, is obviously wrong - when one considers skilled golfers who use a neutral or slightly strong left hand grip. Jeff.
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Post by tapiosantala on Nov 28, 2012 3:39:38 GMT -5
Jeff, IMO you are looking the wrong place to base that movement to supination. It's clear that back of the left hand has to rotate 90 degrees between those mentioned points, but to see the amount of supination we need to look it closer and see the left thumb orientation relative to the elbow pit, not relative to the camera.
As I look those pics 3 and 4, I can't see lot of change at that relation, specially when UD happens bit angled and changes the view. Look how much his left deltoid has moved and whole left arm rotated by that between those 2 positions.
ANd we have to also keep in mind that Oda is releasing his hands way toward the target, not at all left as for example Hogan did.
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Post by imperfectgolfer on Nov 28, 2012 10:10:32 GMT -5
Tapio, You wrote-: " As I look those pics 3 and 4, I can't see lot of change at that relation, specially when UD happens bit angled and changes the view. Look how much his left deltoid has moved and whole left arm rotated by that between those 2 positions." We are seeing things differently. When I look at images 3 and 4, I see a lot of left forearm supination (change in the degree of the rotary relationship between the left thumb and the left antecubital fossa). However, I do agree that part of the counterclockwise rotation of the FLW is due to rotation of the upper torso and left humerus. I think that one can roughly quantify how much the rotation of the FLW between P6 and P7 is due to torso rotation, versus left arm/forearm rotation, by looking at birds-eye view swing videos. Consider this birds-eye view video. Here are capture images from the video. Image 1 is at the P5.5 position when the back of the FLW is still parallel to the inclined plane, and not yet parallel to the ball-target line. The red line is drawn across his shoulder turn angle. Image 2 is just past impact when the back of his FLW faces the target. The red line is drawn across his shoulder turn angle. Note that the back of his FLW must have rotated 90+ degrees between the P5.5 position and impact, but his upper torso has rotated less than 90 degrees. The difference between these two angular rotation measurements must be due to left arm/forearm rotation. Here is another example. Here are capture images. Image 1 is at the P6 position when the back of his FLW is parallel to the ball-target line. I have drawn a red line across his shoulder turn angle. Image 2 is at impact when the back of his FLW must be facing the target. I have drawn another red line across his shoulder turn angle. Image 3 is a composite image where I have superimposed image 1 on image 2 using Photoshop - one can clearly see that the degree of shoulder turn rotation (upper torso rotation) is far less than 90 degrees. Jeff.
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Post by tapiosantala on Nov 28, 2012 10:33:24 GMT -5
Jeff, maybe this video I made few months ago makes it clearer It's very complicated function to follow what really turns to what direction as there is so much happening at the same time and we really can't see the depth from 2D screen. Top down view is IMO best way to really understand what happens, but the problem is still that if we look the shoulder line and forget abduction it can really mislead us. This is good old example I've used to show how the whole forearm turns 90 degrees around the vertical axis and if one would add some independent forearm rotation there, the toe will turn point to the target already But what that all means that there should be not at all lateral movement of the hands and everything has to be based on that rotation. If there is even bit of abduction at the early or middle part of the DSW, one have to rotate his forearms to close the face. If created adduction is kept all the way through, it's possible to get the dace closed without forearm rotation. For me those two ways to swing are the most opposite ones and then there is 1000 steps at gray area between those
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Post by imperfectgolfer on Nov 28, 2012 10:57:36 GMT -5
Tapio, Consider your images. The first image is at the P5.5 position. At that time point, the back of the FLW is still parallel to the mid-downswing's inclined plane. It will then have to rotate about 20-30 degrees to become parallel to the ball-target line, and then another 90 degrees to face the target by impact (second image). However, the angular difference between those two blue lines is far less than 110-120 degrees, and the difference must be due to indepedent left forearm supination, which rotates the left forearm counterclockwise around the axis of the straight left arm. In your video demonstration, that white tape pasted on your left arm does not rotate 110 degrees - it rotates far less. It can only rotate as much as those blue lines rotate in your two images - if there is no significant counterclockwise rotation of the left humerus. Jeff.
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Post by tapiosantala on Nov 28, 2012 11:29:43 GMT -5
It rotated more than 120 degrees for sure Jeff. That's why using 2D videos is very misleading and that's why I told those degrees because I knew people can't see the reality from video.
And about the arm... forget totally the plane, it's biggest distortion there is and only look fro top down. Forget totally the movement downwards and think only that geometry I told. Think only those lines and where the arm is pointing.
The toe of the club points about straight up at the first picture. Now do the test. Put it like that and just rotate around yourself without any abduction and without dropping the club down. Just around the vertical axis and you find the club face is square at the impact point. Now make another test and rotate also your left forearm and you will find out the face is very shut and your right elbow pops out.
Just simple geometry
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Post by imperfectgolfer on Nov 28, 2012 17:50:57 GMT -5
Tapio, I still disagree. Consider this series of images. perfectgolfswingreview.net/TapioLeftArmMotion.jpg [/img] Image 1 - At address, the white patch on the outer surface of your left upper arm is straight-in-line with the back of your FLW, and they both face the target. The back of your FLW is vertical to the ground. Image 2 - your have moved your left arm across your chest (which is an adduction maneuver) as you rotated your upper torso (line between the shoulder sockets) back by a finite amount to your end-backswing position. During that process you have internally rotated your left upper arm in your left shoulder socket - which explains why the back of your FLW is nearly parallel to the ground. If you simply adducted your left arm across your chest while you rotated your upper torso (line across the shoulder sockets) during your backswing action, then the back of the FLW would still be vertical to the ground at your end-backswing position. Image 3 shows that the back of your FLW faces the target and it is also vertical to the ground. That means that you have reversed the internal rotation of the left upper arm in your left shoulder socket during your downswing action. If you simply abducted your left arm during the upper torso's rotation during your downswing action (without any external rotation of the left humeral head within the left shoulder socket), then the back of your FLW would still be facing skywards (like it was at the end-backswing position). Jeff.
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Post by tapiosantala on Nov 28, 2012 23:05:23 GMT -5
Yep, but palm position got no role in this video. It will never be that flat in reality.
But still even there it's easy to see there is about not at all change in thumb and elbow pit relation.
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Post by imperfectgolfer on Nov 29, 2012 0:13:00 GMT -5
Tapio, I disagree 100%. A golfer's left wrist must be flat (like yours) to have an intact LAFW. It may look slightly cupped, because he will have a fist-like grip when holding a rounded grip in his hand, and I label that type of FLW a GFLW, and not an AFLW. However, the GFLW must be aligned parallel to the inclined plane (like the back of your AFLW which is anatomically flat because you are not holding a rounded object in your left hand). Palm position is critical because if a golfer has a neutral left arm/neutral left hand grip at address, then he will have to get his left palm to become parallel to the inclined plane between P2 and P4, so that the back of the FLW is parallel to the inclined plane. That means that he will have to rotate his left arm/forearm clockwise in his backswing action while he adducts his left arm across his chest when he rotates his upper torso during his backswing action - as you have demonstrated. Here is Martin Hall demonstrating how the FLW becomes parallel to the inclined plane between P2 and P4. Here are capture images from his P3 position. Note that his left palm is parallel to the inclined plane in image 3 and 4. He has a GFLW, and not an AFLW, because he is holding a rounded grip in his left hand, but his left palm must still be parallel to the inclined plane. Note that his left thumb is not perfectly straight-in-line with his left elbow pit in image 4 - because he has pronated his left forearm to a small degree. I also think that you are wrong about the elbow pit and the left thumb relationship. In your backswing action, you can see that you rotated your left upper arm clockwise so that the elbow pit faces inwards (towards your body) at the end-backswing position. At address, your elbow pit was facing the ball-target line, which means that it was parallel to the front of your body. The amount the left elbow pit faces inwards (towards your body) at the end-backswing position reflects the amount your left humerus internally rotated during your backswing action. Secondly, I can see that your left thumb is inline with your elbow pit at your end-backswing position, which means that you didn't have to pronate your left forearm to rotate your FLW onto the inclined plane. That is because your left elbow pit faced outwards (towards the ball-target line) at address - when your FLW was facing the target. Most golfers (who adopt a neutral left hand grip) actually have their left elbow pit angled slightly rightwards (away from the target) at address, which means that they have to supinate their left forearm at address to get their FLW to face the target. That means that they will have more left forearm pronation and less internal rotation of their left humerus when they perform a backswing action (like you) that gets the FLW to lie on the inclined plane between P2 and P4. In their downswing, they will therefore have to reverse the process - and have more left forearm supination and less external rotation of the left humerus to get the back of their FLW to face the target by impact. In other words, the amount of left forearm supination (relative to the amount of external rotation of the left humerus) depends on the address alignments of the left upper arm and left forearm (presuming a neutral left hand grip). Jeff.
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Post by tapiosantala on Nov 29, 2012 0:35:20 GMT -5
No Jeff, the problem is that you are watching video and stills, I was here and know how it was. I also know that palm position is not important at that video, because I know what I demonstrate there and what I don't. Palm position got absolutely nothing to do with that demonstration, as it is only to show how much more that deltoid is turned than shoulder line. The difference is about 70-80 degrees and that you are missing when you draw those lines to top down images.
It seems really hard for people to see these movements as they are included for multilevel and multi lever system where everything is moving to different directions.
Here you can also watch the palm position and get the idea what to do
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Post by imperfectgolfer on Nov 29, 2012 1:06:10 GMT -5
Tapio,
We will just have to disagree.
In your latest video, you are claiming that your left forearm is neutral at the P5.5 position and neutral at impact. However, I think that you are probably wrong. I think that the end of your distal radial bone in the left lower forearm (which is a few inches below the tape on your left forearm) has probably rotated slightly out-of-alignment relative to your left elbow pit at the P5.5 position (relative to the P1 and P7 position) - but the amount is probably so small that you are seemingly unaware of that fact. If you look at image 4 of the Martin Hall images, you can see that his left thumb is slightly more rotated counterclockwise than his left elbow pit. That has to be reversed in the downswing, which requires a small amount of left forearm supination.
If you are not performing any left forearm supination between the P5.5 position and impact, then it simply means that all the left arm rotation required to get from P1 to P3 (and therefore back from P5 to to P7) is due to rotation of the left humerus. If you deny that you are rotating the left arm about its longitudinal axis, then we perceive reality very differently, because I think that your left elbow pit is not parallel to the front of your torso at the P5.5 position, and I perceive that it is rotated clockwise/inwards slightly (relative to the front of your torso) - like Martin Halls' left elbow pit, which is rotated clockwise relative to the front of his torso in image 3 and image 4.
Of course, one should never over-supinate the left forearm in the downswing because that will radically close the face as you have demonstrated. One should only supinate the left forearm to get back to the same left forearm alignment one adopted at address.
In your first video demonstration you are only trying to show that the deltoid area of the left upper arm has moved more than the shoulder turn angle, and that merely reflects the degree the left humerus is adducting (across the front of your chest) in your backswing action (while the shoulder turn angle changes). Palm position has no relevance to your demonstration. However, I noted that you are not only adducting your left humerus, you are also rotating the left humerus about its longitudinal axis, and that's why I think that looking at the positional alignment of your left palm is so important - because one needs to get the left palm parallel to the inclined plane between P2 and P4 in a "real life" golf swing.
Jeff.
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Post by imperfectgolfer on Nov 29, 2012 1:29:41 GMT -5
To all forum members - try this challenge. Adopt a neutral left arm at address (where the left elbow pit faces the ball-target line) and adopt a neutral left hand grip. Then try and get your left palm/back of your GFLW/watchface to become parallel to the inclined plane by the P3 position (like Martin Hall in image 3 and image 4) I personally think that only three biomechanical actions are needed (ignoring any pelvic motion and any left arm elevation) - i) a rotation of the torso (left shoulder socket); ii) adduction of the left humerus (left arm) and iii) internal rotation of the left humerus in the left shoulder socket. Can any of you achieve that goal without using action iii) - internal rotation of the left humerus in the left shoulder socket? If you can, please explain how that is humanly possible. Jeff.
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Post by imperfectgolfer on Nov 29, 2012 22:05:32 GMT -5
In his arm rotation video, Tapio constantly talks about rotating the "whole system" when he moves his arms/club from the P5.5 position to impact. He seemingly believes that it doesn't involve any rotation of the left arm around its longitudinal axis. I believe that he is wrong. Consider my explanation. Image 1 shows how he adopts a neutral position when he holds the ball at address. His left elbow pit (antecubital fossa) is neutral and it faces outwards so that it is roughly parallel to the front of his torso and the ball-target line. Note that the back of his FLW is vertical and it faces the target. Image 2 shows him in mid-backswing (roughly at the P3 position). Note that he has rotated his torso clockwise and also adducted his left arm across the front of his torso. If he was performing a pure left arm adduction maneuver, without any rotation of the left arm around its longitudinal axis, then the back of his FLW should be near-vertical at the P3 position. However, one can see that the back of his FLW has rotated over so that it faces slightly more skywards, and that means that he is internally rotating his left arm around its longitudinal axis while he adducts his left arm. Image 3 shows him at his end-backswing/P4 position. Note that the back of his FLW faces even more skywards, which means that he is rotating his left arm clockwise around its longitudinal axis even more as he moves from the P3 position to the P4 position. Image 4 shows him at impact with the back of his FLW vertical and facing the target and his left elbow pit is again parallel to the front of his torso (neutral position - as it was at address). To get from the P4 position to impact, he had to reverse all the biomechanical events that happened in the backswing, but in the reverse direction. That means that he must be rotating his left arm around its longitudinal axis in a counterclockwise direction when he "rotates the whole system" towards an impact alignment. Image 5 shows him at roughly the P5.5 position. I have drawn a blue arrow to show where the left elbow pit is pointing. It is pointing in a relatively horizontal direction and not a near-vertical direction, and the difference in the angle between the blue arrowed line and near-vertical is roughly a reflection of how much he has rotated his left upper arm around its longitudinal axis. However, note that the back of his GFLW and clubshaft is on an even more horizontal plane (red arrowed line) which means that he has pronated his left forearm to get his clubshaft to lie on such a shallow plane at the P5.5 position. Image 6 shows him at impact - where he is again in a neutral position (equivalent to image 4). Tapio talks about "rotating the whole system" as a single unit between the P5.5 position and impact and he seemingly believes that is entirely due to a torso rotation movement combined with a left arm abduction movement. However, the reality is that it also involves *a significant amount of counterclockwise rotation of the left upper arm around its longitudinal axis combined with a significant amount of left forearm supination - so that he can get his left arm back to its neutral alignment by impact. (* the bold-highlighted biomechanical actions represent the release of PA#3) Jeff.
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Post by tapiosantala on Nov 30, 2012 8:02:40 GMT -5
You believe I'm wrong and I know exactly what I did. There is multiple movements that rotates that arm relative to the camera, but not even slightest forearm rotation around it's own axis. Would you really believe I would post that if I'm not 100% sure?
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Post by imperfectgolfer on Nov 30, 2012 10:26:11 GMT -5
Tapio, As I stated previously, if you do not really use left forearm rotary motions, then all the rotary motions that you use in the release of PA#3 must be due to a left upper arm rotation. The fact remains that any golfer who adopts a neutral left arm and neutral left hand grip at address must rotate their left arm around its longitudinal axis in the backswing and downswing. In the downswing, most of the rotation must occur between P6.5 and P7 (when the club is almost completely released) to prevent throwing the club over-the-plane. The amount of left forearm rotation versus left upper arm rotation varies between golfers - and golfers who have limited shoulder joint mobility will use more forearm rotation during the release of PA#3. Here are newly created images of John Oda's late downswing and they include a view of his left elbow pit. Image 1 shows him at the P6.5 position. The back of his FLW is nearly still parallel to the ball-target line and he has to rotate his FLW about ~60-80 degrees between that time point and P7.1 (image 3). There is very little shoulder socket rotation (due to torso rotation) during that time period, so most of the rotation of the FLW must be due to arm/forearm motion. Note that his left elbow pit faces away from the target im image 1 and it has only rotated counterclockwise <45 degrees by image 3. So, a significant amount of the counterclockwise rotation of the FLW between P6.5 and P7.1 is due to left forearm supination (which is also confirmed by the fact that the radial border of his left forearm is not straight-in-line with his left elbow pit in image3).
Jeff.
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