|
|
Post by imperfectgolfer on Jul 9, 2020 9:19:34 GMT -5
Dr Mann Do you have any 3D graphs of golfers who aren't DH'ers and don't have any blip-plateaus? If those blips still occur in both DHers and non-DH'ers , then a claim might be made that it was due to club/ball impact (just like Dan Carraher claimed in an older earlier thread). DG I have too few 3D graphs to make that assessment. I wish that I could access Jon Sinclair's data base to study this issue. Jeff. |
|
|
|
Post by dubiousgolfer on Jul 9, 2020 9:46:55 GMT -5
Dr Mann Do you have any 3D graphs of golfers who aren't DH'ers and don't have any blip-plateaus? If those blips still occur in both DHers and non-DH'ers , then a claim might be made that it was due to club/ball impact (just like Dan Carraher claimed in an older earlier thread). DG I have too few 3D graphs to make that assessment. I wish that I could access Jon Sinclair's data base to study this issue. Jeff. Dr Mann Why don't you send him a list of golfers that you know for certain are not DH'ers and just ask him 'generally' whether their lead forearm supination/pronation graphs all show a 'blip plateau' like Jon Rahm. It's just a yes/no answer but then you'll know whether those blip characteristics are caused by DH hand release or something else. DG |
|
|
|
Post by imperfectgolfer on Jul 9, 2020 12:16:13 GMT -5
I have too few 3D graphs to make that assessment. I wish that I could access Jon Sinclair's data base to study this issue. Jeff. Dr Mann Why don't you send him a list of golfers that you know for certain are not DH'ers and just ask him 'generally' whether their lead forearm supination/pronation graphs all show a 'blip plateau' like Jon Rahm. It's just a yes/no answer but then you'll know whether those blip characteristics are caused by DH hand release or something else. DG It's a good suggestion. However, I suspect that Jon Sinclair will not provide me a with list of pro golfers who he has studied because of his confidentiality agreements, so I cannot choose a pro golfer from his list who I know is not a DHer. Jeff. |
|
|
|
Post by imperfectgolfer on Jul 12, 2020 18:29:52 GMT -5
I sent Jon Sinclair a link to the following web page showing my collection of DH-hand release action images.
He stated that he had 3D graphs of a few of those pro golfers, and he stated that none of them showed a blip-plateau phenomenon of the lead wrist flexion-extension graph between P7 => P7.2. (as seen in Jon Rahm's swing). He sent me one of their 3D graphs - as an example.
Here is the 3D graph.
Here is an enlarged image focusing on the P7 => P7.2 time period, which I have colored in yellow.
Note the blip-plateau in the lead wrist flexion (green graph) and note that the lead wrist supination graph (in blue) becomes far less steep after P7.2 and that there is small blip-in-the-slope between P7 => P7.2.
This is exactly what one would expect to see in a 3D graph of a DHer!
I think that Jon does not realize that one will not always see a distinct blip-plateau at a sampling rate of 240 samples/second and one probably needs a sampling rate of >2,400 samples/second to more clearly see/define any blip-plateau phenomenon.
Jeff.
|
|
|
|
Post by dubiousgolfer on Jul 12, 2020 18:57:51 GMT -5
Dr Mann
There also seems to be slight change in the slope of the Sup-Pro line for that 'plateau' period of time. Steeper into impact, slightly flatter , then steeper again.
DG
|
|
|
|
Post by imperfectgolfer on Jul 13, 2020 9:54:22 GMT -5
Dr Mann There also seems to be slight change in the slope of the Sup-Pro line for that 'plateau' period of time. Steeper into impact, slightly flatter , then steeper again. DG Yes - and that is characteristic of a DHer (like Tommy Fleetwood). There are two phases of left forearm supination - i) the pre-impact phase needed to square the clubface by impact and ii) the post impact finish swivel phase needed to rotate the clubshaft back up onto the inclined plane. However, there is far less left forearm supination happening in the transition time period between these two phases and that happens around P7 => P7.2 (or to P7.4+).  Image 1 is at impact, image 2 is at P7.4, image 3 is at P7.7 and image 4 is at P8.
I have a placed a green dot in the middle of his left antecubital fossa (elbow pit) and 3 red dots in a straight-line over his left radial bone just above his left wrist crease. A changing rotational relationship between the green dot and the red dots (where the red dots rotate faster counterclockwise than the green dot) would reflect the presence of left forearm supination.
Note that you cannot see his left antecubital fossa in image 1 (impact) because his left humerus is internally rotated at impact. Note that the back of his left hand and watchface area of his left lower forearm is facing the camera at impact - which is expected considering the fact that he uses a strong left hand grip.
Note that you can clearly see the green dot at P7.4 (image 2) which means that he has significantly rotated his left humerus counterclockwise between impact and P7.4. Note that the red dots (signifying the position of his left lower radial bone) have not likely rotated counterclockwise more than his green dot (signifying the position of his left antecubital fossa) between impact and P7.4 and that suggests that there is no significant amount of left forearm supination happening between impact and P7.4.
Note that the back of his left hand and watchface area of his left lower forearm continues to rotate counterclockwise between P7.4 (image 2) and P7.7 (image 3) and that it is primarily due to continued external rotation of his left humerus without any additional left forearm supination component (as evidenced by the fact that the red dots are not rotating counterclockwise faster than the green dot between P7.4 and P7.7).
Note that he transitions into his finish swivel phase after P7.7 (image 4) and that requires a lot of lead forearm supination.
Jeff.
|
|
|
|
Post by dubiousgolfer on Jul 13, 2020 10:25:44 GMT -5
Many thanks Dr Mann
DG
|
|
|
|
Post by imperfectgolfer on Jul 18, 2020 10:05:48 GMT -5
An update on my e-mail discussion with Jon Sinclair. Jon stated that any blip-plateau phenomenon seen immediately post-impact in his lead wrist flexion-extension graphs is due to ball collision and he states that it is seen in all his pro golfers (DHers and non-DHers). He also stated that it disappears if a ball is absent. Jon stated that he has never seen a pro golfer who does not rapidly-and-massively extend the lead wrist through impact. He also stated that he does not believe in the legitimacy of Jordan Spieth's lead wrist flexion value of 9 degrees at impact and 4 degrees at P7.4 obtained using a different 3D system. Jon stated that " I have never seen a shaft stay lined up with the lead forearm for any meaningful length of time". I then sent him these capture images of Viktor Hovland's DH-hand release action. 
Image 1 is at impact, image 2 is at P7.1, image 3 is at P7.2, image 4 is at P7.3 and image 5 is at P7.4.
I have drawn a red line along his left lower radial bone in his lower left forearm and a blue line along his proximal clubshaft.
It is obvious to me that his clubshaft is straight-line-aligned with his left lower radial bone all the way between P7 => P7.4 and that he is not allowing his clubshaft to bypass his lead forearm (from an angular rotational perspective). Between P7 => P7.4 he is rotating the back of his lead hand counterclockwise and it is due a finite degree of external rotation of his left humerus combined with a small degree of lead forearm supination, but the total amount of lead hand rotation has to be small enough to allow him to keep his clubface square to his clubhead arc all the way between P7 => P7.4. It is also obvious to me that Viktor is not rapidly-and-massively extending his lead wrist between P7 => P7.4. In fact, I think that the degree of lead wrist flexion between P7 => P7.4 must be <10 degrees - how can it be greater if the clubshaft and lead forearm remain straight-line-aligned?
Jon Sinclair has not responded to my question, and he has cut-off all communication with me.
Interestingly, there is other "3D-evidence" that the lead wrist does not extend rapidly through impact in some pro golfers. Here is a capture image from the video showing the stable wrist flexion-extension pattern through impact. Note that the lead wrist flexion graph (green graph) shows a plateau in lead wrist flexion immediately after impact - before it then moves more rapidly towards extension. Jeff.
|
|
|
|
Post by dubiousgolfer on Jul 18, 2020 12:10:31 GMT -5
Interesting HackMotion video especially when he gives an opinion (at 12:10) regarding 'Flexion to Extension Model B' being better for long clubs because the 'start line' vector stays closer to the target (more change in the vertical component than right to left).
He also mentions that 'old school' Swing Option A 'Stable Wrist Flexion/Extension' pattern has higher rotation (due to pivot/arm rotation). Does that mean the purple graph is usually steeper through impact than Option B & C?
DG
|
|
|
|
Post by imperfectgolfer on Jul 18, 2020 13:19:40 GMT -5
Interesting HackMotion video especially when he gives an opinion (at 12:10) regarding 'Flexion to Extension Model B' being better for long clubs because the 'start line' vector stays closer to the target (more change in the vertical component than right to left). He also mentions that 'old school' Swing Option A 'Stable Wrist Flexion/Extension' pattern has higher rotation (due to pivot/arm rotation). Does that mean the purple graph is usually steeper through impact than Option B & C? DG Scott does imply that swing option A has more hand rotation through impact, which he claims is due to pivot/arm rotation. However, his HackMotion device presumably cannot differentiate between rotation of the lead hand due to external rotation of the lead humerus, or from lead forearm supination, and/or from hand rotation due to left wrist circumduction. I cannot understand how pivot rotation can independently affect hand rotation - without working through rotation of the lead arm. Regarding swing option B, he claims that clubhead momentum is released through lead wrist extension, and he states that Viktor Hovland is an example of a golfer who uses swing option B, but I don't believe that VH manifests rapid lead wrist extension between P7 => P7.4 if his clubshaft remains continuously straight-line-aligned with his lead forearm during that P7 => P7.4 time period. How is that possible? Jeff. |
|
|
|
Post by dubiousgolfer on Jul 18, 2020 17:31:06 GMT -5
So does this mean for long clubs , 'Flexion to Extension Model B' has less dispersion than a DHer ?
DG
|
|
|
|
Post by syllogist on Jul 18, 2020 18:48:51 GMT -5
Dr. Mann,
Hovland has a bowed left wrist at the top. I believe that Hovland does not exhibit rapid lead wrist extension at P7 or slightly beyond because of club deceleration upon club/ball collision.
S
|
|
|
|
Post by dubiousgolfer on Jul 18, 2020 19:12:37 GMT -5
I think this HackMotion video shows the 3 models in a clearer way with example golfer swings and graphs .
DG
|
|
|
|
Post by imperfectgolfer on Jul 18, 2020 19:12:39 GMT -5
So does this mean for long clubs , 'Flexion to Extension Model B' has less dispersion than a DHer ? DG Why do you make this assumption? Scott's model B shows continued lead wrist flexion => extension happening continuously through impact, which is theoretically incompatible with a DH-hand release action? Jeff. |
|
|
|
Post by imperfectgolfer on Jul 18, 2020 19:16:12 GMT -5
Dr. Mann, Hovland has a bowed left wrist at the top. I believe that Hovland does not exhibit rapid lead wrist extension at P7 or slightly beyond because of club deceleration upon club/ball collision. S I don't understand your reasoning! Are you claiming that rapid lead wrist extension through P7 does not happen because of clubhead deceleration as a result of ball contact in pro golfers who have a bowed lead wrist at P4, or you believe that it happens in all pro golfers? Jeff. |
|
