DG,
I find those TPI graphs from the Sandtrap forum very convincing, which means that you are correct to state that the positive Y axis represents right forearm pronation.
That throws a "spanner in the works" when it comes to claiming that the Jon Sinclair video graph represents Trevor Immelman's swing action. According to that graph, the right forearm is 45 degrees pronated at address and 30 degrees pronated at P4. Then, it pronates 15 degrees more between P4 => P6 before gaining another 5 degrees of further pronation between P6 => P7. I cannot fathom how the right forearm can increasingly pronate between P4 => P6 if the golfer uses a right arm adduction maneuver with a pitch elbow motion. It suggests a punch elbow motion (ala "Malaska Move"), which I do not associate with a professional golfer's swing action.
I am flummoxed!
Jeff.
Dr Mann
I found another video below with Jon Sinclair and this time the TPI graph for the trail wrist does seem to show the positive y-axis as supination rather than pronation (see 25:15) . Maybe it's a quirk of the TPI database where the y-axis becomes pronation when they create those tables.
Quite a few interesting graphs in the video which you might find interesting although Jon Sinclair (near the end of the video) still insists on rapid extension of lead wrist through impact . I got the feeling that Larry Rinker seemed rather confused about it all and I honestly cannot blame him.
Some points I noted below:
1. 100 degrees variance between lead wrist extension - flexion in the whole TPI database for PGA Pro players and a standard deviation of 31 degrees (for 68% of players). JS seem to imply its an idiosyncratic 'style' of the golfer.
2. The variance in trail wrist wrist extension is a "tight window all the way through the ball for Tour players" (according to Jon Sinclair at 13:59)
3. Is it more likely for a golfer to have a flexed lead wrist at P4 if his takeaway keeps the club more outside his hands (see video at around 12:30)?
4. At 14:27 they discuss Sergio Garcia and mention him under the plane but 'tumbling' the club toward the plane.
5. Larry Rinker (15:26) says that "when the club has balance it almost swings itself through the impact area and the clubface squares"
6. At 16:50 JS seems to imply a tumbling over move (like Mike Malaska) . He says "at shaft parallel we want the club to come over" and also mentions Sergio having to 'tumble over' right away (because he's so "laid off").
7. At 18:17 JS says the correct move from P4 is that "the club has to move up and back away from the golfer you know they've done it right"
8. At 20:55 they show the trail wrist graph range for the PGA pros (5 -iron). It shows the 'tighter window' of variance and JS doesn't regard that as 'style'.
9. At 22:55 JS shows his own 3D graphs and he adds his avatar and another graph showing the 'club axial velocity' (to reflect ROC). He says that the club closes due to increased lead wrist flexion in the early downswing and both arms will start to supinate from around P5.5 (see 24:20 - 25:35). That the supination of both forearms will "help the club stay behind as the hands are getting forward".
10. At 26:12 it is clear that the trail wrist graph is showing supination happening into impact
11. At 27:18 he discusses impact and lead wrist flexion-extension and he says "we need to encourage that motion like a frisbee throw". At 29:05 he says that "everybody's wrist is going very rapidly into extension' .
DG
Thanks for bringing that video to our attention.
Here are my comments in response to points that you raised.
You wrote-: "1. 100 degrees variance between lead wrist extension - flexion in the whole TPI database for PGA Pro players and a standard deviation of 31 degrees (for 68% of players). JS seem to imply its an idiosyncratic 'style' of the golfer.
Here is a capture image from the video showing the variance in left wrist extension/flexion at P4.
The variance at P4 is only 31 degrees at the P4 position for 68% of golfers. That's not large considering that some pro golfers prefer to have a cupped left wrist at P4 while other golfers prefer to have a flexed left wrist at P4.
What is interesting is that the amount of left wrist flexion happening in the early downswing between P4 => P5 is very small and the "blue" graph golfer (which represents the average pro golfer) only goes from 10 degrees extended at P4 to 0 degrees extended (= AFLW) by P5. Note that the average pro golfer then only gains another 10 degrees of left wrist flexion by ~P6 and that there is a "plateau" in the graph between ~P6 and impact where there is <5 degrees of change in the degree of left wrist flexion. That extra 10 degrees of left wrist flexion is very small considering that the left wrist naturally/automatically moves towards flexion when the left wrist moves towards ulnar deviation - if the golfer maintains an intact GFLW/LFFW.
Here again is Henrik Stenson's intact LFFW/GFLW swing action.
HS has an intact LFFW/GFLW at P4 and at P5.5 and at P6.5. However, his left wrist is overtly cupped at P4 and at least 20 degrees more extended than his left wrist at P5.5 (where he has an AFLW). Note that his left wrist does not seem to bow much more (< 10 degrees) between P5.5 => P6.5 which is very compatible with the "plateau" seen in the above Sinclair graph.
In other words, that Sinclair "blue" graph is exactly what one would expect to naturally see in a pro golfer who adopts a neutral left hand grip and who naturally/automatically flexes his left wrist more between P4 => P6.5 while maintaining an intact LFFW/GFLW (like Henrik Stenson).
Another point of interest regarding the "blue" graph, is that the left wrist only moves towards extension by another 10 degrees in the early-mid followthrough, which probably means that there is <5 degrees of left wrist extending happening between P7 => P7.2. Such a small amount of left wrist extending between P7 => P7.2 is even compatible with a DH-hand release action!
You wrote-: "2. The variance in trail wrist wrist extension is a "tight window all the way through the ball for Tour players" (according to Jon Sinclair at 13:59)."
That's not surprising. Many skilled golfers maximally extend their right wrist at P4, or later at P5.5, and then maintain an extended right wrist all the way to P6+.
You wrote-: "Is it more likely for a golfer to have a flexed lead wrist at P4 if his takeaway keeps the club more outside his hands (see video at around 12:30)?"
Not necessarily.
You wrote-: "4. At 14:27 they discuss Sergio Garcia and mention him under the plane but 'tumbling' the club toward the plane."
Sergio is atypical in that he shallows his clubshaft very abruptly between P4 => P5 and he therefore has to "tumble" a small amount to get back on-plane by P5.5.
Here are capture images of SG's downswing.
The red plane line is the hand plane.
I have drawn a short blue line parallel to the back of his GFLW. Note that an extension of that "blue line" points outside the ball-target line at P5 (image 2), but it points at the ball-target line at P5.2. (image 3). However, SG does not "tumble" his clubshaft further in an "over-the-plane-Malaska" manner between P5.2 (image 3) and P6.2 (image 6) and his clubshaft actually moves in an underplane manner under his hands between P5.5 => P6.2.
You wrote-: "5. Larry Rinker (15:26) says that "when the club has balance it almost swings itself through the impact area and the clubface squares".
That's a vague statement that sheds no insight (light) on golf swing swing biomechanics.
You wrote-: "At 22:55 JS shows his own 3D graphs and he adds his avatar and another graph showing the 'club axial velocity' (to reflect ROC). He says that the club closes due to increased lead wrist flexion in the early downswing and both arms will start to supinate from around P5.5 (see 24:20 - 25:35). That the supination of both forearms will "help the club stay behind as the hands are getting forward".
Here are capture images of JS's five-iron swing's 3D data.
I captured that image at the P5.2 position (see vertical green line).
Note the very small amount of handle twist velocity happening between P4 => P5.2. It is very small and it is probably due to a small degree of twistaway that happens when any skilled golfer pulls the club handle downwards between P4 => P5.2. It is very biomechanically natural for a skilled to grip the club handle more tightly with the left hand's 3rd, and 4th and 5th fingers as he pulls the club handle downplane between P4 and P5.2 and a small degree of clubface-closing due to a twistaway phenomenon is not unexpected. Note that his clubface in the avatar image is still parallel to the watchface area of his left lower forearm and that signifies a negligible amount of clubface-closing. Also, note that his left wrist still looks dorsiflexed and it does not even look bowed. I do not believe that any clubface-closing seen between P4 => P5.2 is due to a left wrist bowing maneuver (which only angulates the shaft in the absence of twistaway) and it must be due a twistaway phenomenon.
You quoted JS as follows-: "At 16:50 JS seems to imply a tumbling over move (like Mike Malaska) . He says "at shaft parallel we want the club to come over". JS seems to be implying a "Malaska Move" tumble motion, but that does not happen in his five iron swing because that would require right forearm pronation. Note that JS's right forearm graph (which is at zero in that graph at P5.2) supinates after P5.2 and it never pronates at any time after P5.2. JS even demonstrated a "stone skipping action", or "sidearm/underhand baseball pitching motion", of his right arm in the video and that requires a continuous supinatory motion of the right forearm that may continue all the way to impact.
Here is Ben Hogan demonstrating that side-arm pitching motion.
If done well, the right forearm pronation phase will only happen very late in the release action.
Here is Trevor Immelman's driver swing action.
Image 2 is at P6, image 3 is at P6.5 and image 4 is at impact.
Note that TI's right forearm is very supinated between P6 => P7 and that allows him to keep his right hand under the club handle between P6 => P6.5. Note that visual evidence of significant right forearm pronation is delayed to impact (image 4) and through impact (image 5) and that gets the right hand to face the target through impact.
You wrote-: "At 27:18 he discusses impact and lead wrist flexion-extension and he says "we need to encourage that motion like a frisbee throw". At 29:05 he says that "everybody's wrist is going very rapidly into extension'."
JS talks of snapping the wrist in a frisbee-throwing manner. However, we know that DHers do not allow their left wrist to rapidly extend between P7 => P7.4.
Here is Jordan Spieth's superb DH-hand release action.
Image 1 is at P7, image 2 is at P7.2 and image 3 is at P7.4.
According to Dan Carraher, JS has 9 degrees of left wrist flexion at impact and 4 degrees at P7.4. That means that his left wrist only moved 5 degrees towards extension between P7 => P7.4. That's not rapid/massive "left wrist extending" and it is a negligible amount.
Jeff.
p.s. I plan to purchase Jon Sinclair's 2.5 hour video for $99 and I suspect that I will have many more comments to make in future posts.
