Does bowing the lead wrist close the clubface?

[imperfectgolfer]

DG,

You wrote-: "I seem to remember a previous thread/posts where we were looking at handle twist velocity Grip roll and Clubface Closure Rate (I think it was an AMG Gears video) for some pro golfers and you asked a question why the 'clubface closure rate' decreased approaching impact. I'm now wondering whether your above posts offer a possible explanation for that effect.".

I do now think that the fact that the lead wrist is in ulnar deviation as the clubshaft approaches impact can explain why the clubface closure rate per unit amount of clubhead travel is decreased near impact.

You also wrote-: "Can't see the same 'clubface closure reduction' effect approaching impact in the following video especially for Jonas Blixt. I needed to slow-mo the video and monitor the clubface closure measure from P6.5 ->P7 and didn't see any decrease in Grip Roll or Clubface Closure Rate."

Jonas Blixt uses an ultra-strong lead hand grip and he therefore does not use the standard PA#3 release action in his later downswing and I would not expect to see differences in grip roll/clubface closure rates nearing impact compared to P6 - P6.5.

By the way, you brought up the topic of how the angle of the clubshaft relative to the clubhead arc can affect the relationship between the grip roll rate and the clubface ROC. I now think that this problem issue is even more complex because one has to take lead hand grip strength into account.

For example, I wrote in that post-: "Note that at P7, that the clubshaft is perpendicular to the clubhead arc and the clubface is directed in the same direction as the clubhead path. Note that the back of the GFLW is directed towards the target and it is angled perpendicular to the clubhead arc at P7. Therefore, if the peripheral clubshaft just above the hosel rotates 10 degrees counterclockwise due to grip roll, then the clubface should close 10 degrees relative to the clubhead arc as it rotates around the hosel axis by 10 degrees."

That scenario may apply to a weak-neutral lead hand grip, but it will not apply to a golfer who uses a very strong lead hand grip where the back of the lead hand is nearly perpendicular to the clubhead path at impact. Under those conditions, if grip roll happens due to any lead wrist circumductory roll motion, or any lead forearm supination, then the roll motion will angled at nearly a right angle relative to the clubhead path direction and it is much more likely to affect the dynamic loft than the clubface ROC (relative to the clubhead arc).

I also wrote-: "Now, consider the scenario at P5. Note that the back of the GFLW is parallel to the clubhead arc (and not perpendicular to the clubhead arc) and that means that the clubface (which is parallel to the inclined plane) is facing a skywards direction that is angled roughly 90 degrees relative to the clubhead arc. Therefore, if the peripheral clubshaft just above the hosel rotates counterclockwise 10 degrees secondary to grip roll (due to a "reverse motorcycle move") then the clubface will close counterclockwise by 10 degrees relative to a plane that is perpendicular to the direction of the clubhead arc. I have no idea how that will translate to any measurement of clubface-closing that is relative to the clubhead arc (in the same direction as the clubhead arc) - especially considering the additional fact that the peripheral clubshaft is angled relative to the clubhead arc and it is not perfectly perpendicular to the clubhead arc."

If that description is not complex enough, then consider what effect a stronger lead hand grip will have on that same scenario.

Here are capture images of Dustin Johnson's early downswing.

Image 2 is at P5.2, image 3 is at P5.5 and image 3 is at P6.

DJ's clubface looks closed relative to the clubhead arc and swingplane in those 3 images and there are two factors that cause that "look". The one factor is that his clubface is closed relative to the back of his lead hand because he adopted a moderately strong lead hand grip at address. The second factor is that bowing his lead wrist causes grip roll in a clubface closing direction, but that clubface closing direction is not necessarily in the same clubface closing direction as that caused by factor number one. Also, the clubface closing effect due to factor number two can vary in roll direction because the clubshaft is angled differently relative to the clubhead arc at all time points between P5.2 => P6.

Phew!

That's a very complex scenario and I do not think that the golf instructional world can appreciate the complexity of clearly understanding this clubface closing problem issue!

Jeff.

[dubiousgolfer]

Yes , its really how the rotation of the shaft ultimately effects the clubface at impact when:

1. The clubshaft is aligned in a more parallel direction relative to the clubhead path
2. The clubshaft is aligned more perpendicular direction relative to the clubhead path

If we knew that , then one could maybe start to theorise why golfers use specific anatomical movements in their swings

DG

[imperfectgolfer]

Oct 10, 2020 12:06:44 GMT -5 dubiousgolfer said:

Yes , its really how the rotation of the shaft ultimately effects the clubface at impact when:

1. The clubshaft is aligned in a more parallel direction relative to the clubhead path
2. The clubshaft is aligned more perpendicular direction relative to the clubhead path

If we knew that , then one could maybe start to theorise why golfers use specific anatomical movements in their swings

DG

One could reasonably argue that it only becomes important to evaluate the clubface's degree of closure relative to the clubhead arc and ball-target line in the later downswing after P6 when the club is on the functional swingplane and the lead wrist is moving towards ulnar deviation. That's why I used P6.2 as my starting point in my capture image evaluation of different pro golfer's swings. It definitely appears that pro golfers who use a bowed lead wrist technique in the backswing, or early-mid downswing, have 10-30 degrees of clubface closure at P6.2. That has the potential advantage that it can blend more smoothly/evenly into the clubface closure that will happen after P6.2 secondary to the PA#3 release action. What is not perfectly clear is whether it decreases the amount of lead forearm supination required during the PA#3 release action in order to get a square clubface by impact. Generally, I think that if a pro golfer maintains a markedly bowed lead wrist all the way into impact (like Colinn Morikawa) that the large degree of forward clubshaft angulation at impact necessitates further lead forearm supination in order to square the clubface at impact. That may not apply to golfers (like Jordan Spieth) who have minimal lead wrist bowing at impact with minimal forward shaft lean.

Another interesting question is whether there is a very strong positive correlation between using a bowed lead wrist technique and having a very open pelvis/upper torso alignment at impact. The pro golfers that I have analysed - Colinn Morikawa, Gary Woodland, Jon Rahm, Dustin Johnson, Cameron Champ and Jordan Spieth - all have a very open pelvis/torso alignment at impact. I cannot think of a pro golfer, who uses the bowed lead wrist technique, who is not very open at impact. However, many pro golfers, who use the intact LAFW/GFLW technique, also have a very open pelvis/torso alignment at impact if they use the DH-hand release technique.

Jeff.

[imperfectgolfer]

I have discussed the effect of lead wrist bowing on clubshaft angulation and clubface closing, but it has another effect and that is related to the shape of the clubhead path between P5.5 => P7.

Look at these capture images of Dustin Johnson's downswing action.

Between P4 => P5.2 (image 2) DJ's lead wrist bowing closes the clubface relative to his clubhead arc, but it does not alter the clubshaft angle.

After P5.2, when the lead wrist starts to uncock and move towards ulnar deviation, lead wrist bowing causes the clubshaft to angle downards-and-inwards so that it creates a clubhead arc that approaches the ball more from the "inside" and where the clubhead path is more in-to-out than seen in a golfer who does not use the bowed lead wrist technique. The clubhead arc is also steeper and there is not an extended "flat spot" where the clubhead travels parallel to the ground for >12" between P6.7 => P7.

This same phenomenon can be seen in Colinn Morikawa's golf swing action.

Face-on capture images of CM's driver swing action.

Note how steep the clubhead arc is between P6.5 => P7 as the clubhead approaches the ball. At P6.8 (image 3) his clubhead is still moving downwards and there is only a few inches before impact where it can level-out.

DTL view of CCM's driver swing

DTL view of CM's iron swing

The DTL capture images show how the clubhead moves under the hands between P5.5 => P6.2 and how the clubhead arc is more in-to-out between P6.2 => P7.

Here is Tiger Woods' clubhead arc in his driver swing.

Note that the clubhead arc is shallower and that there is an extended "flat spot" for about 12" before impact where the clubhead is traveling parallel to the ground, and where the clubface is closing steadily due to the release of PA#3.

Jeff.

[dubiousgolfer]

Dr Mann

So do you think a bowed lead wrist goes 'hand in hand' with a steeper angle of attack and a shorter overall clubhead path from P6-P7? Could it be that the golfers who prefer a steeper angle of attack , find it a necessity to close the clubface by bowing their lead wrist earlier between P4-P6 (otherwise they won't have enough time to square the clubface with PA#3 because of the shorter clubhead path)?

DG

[imperfectgolfer]

Oct 11, 2020 19:36:53 GMT -5 dubiousgolfer said:

Dr Mann

So do you think a bowed lead wrist goes 'hand in hand' with a steeper angle of attack and a shorter overall clubhead path from P6-P7? Could it be that the golfers who prefer a steeper angle of attack , find it a necessity to close the clubface by bowing their lead wrist earlier between P4-P6 (otherwise they won't have enough time to square the clubface with PA#3 because of the shorter clubhead path)?

DG

That relationship may be true if the golfer wants to have an exaggerated degree of negative clubhead attack angle at impact (eg. for punch shots or hitting out of deep rough with grass behind the ball), but I suspect that it is not a factor for standard shots off the fairway where the variance in clubhead attack angle between different pro golfers is not large. I think that many pro golfers, who use a bowed lead wrist technique that causes an exaggerated in-to-out clubhead path between P5.5 => P7, may like the fact that it allows them to more easily hit fades and avoid hooking the ball left.

Jeff.

[dubiousgolfer]

Dr Mann

I was getting confused about how a bowed/cupped wrist affects the clubface , especially at impact but I think I understand now.

For example:

If I attached one of those magnetic lie pointer attachments to the clubface sweetspot like the below image , stood the shaft vertical then bowed/cupped my wrist such that the shaft swung in a vertical plane , the clubs loft would change but the pointer targetwards direction would remain unchanged. If I tilted the shaft shallower and then bowed my wrist, the pointer direction would shift to the right but if I cupped my wrist , the pointer would move to the left.

So even though the club shaft is not 'rotating' around its its longitudinal axis , the bowing and cupping will cause the clubface orientation relative to target line to change. Further , if the instantaneous radius of the clubhead path is smaller (ie. because of the bowing/cupping at wrist joint level) , won't the rate of change of clubface orientation with target line also be greater?

Therefore just pure flipping through impact will cause the clubface to point left.



Dave Tutelman's website mentions the effect of cupping the wrist before impact.

www.tutelman.com/golf/swing/accelerateThru.php

"The left wrist is cupped, rather than the proper flat or even bowed left wrist. We know that a bowed wrist at impact (or a flat wrist at the very least) is desirable for a solid hit. A cupped wrist, on the other hand, is associated with lost clubhead speed, fat or thin shots, or too-high balloon shots. It is also likely to point the clubface to the left, resulting in a pull or even a pull-hook. (Think about it this way: if the swing plane were perfectly vertical, then a cupped left wrist would add loft. Since the swing plane is not vertical but tilted, some of that "loft" turns into a left-facing angle.)"


But I don't think the "rate of change of loft"  being converted to  " rate of change of left-facing angle" is factored into Phil Cheetham's dissertation and formulae (see his comment below).

"Clubhead lead will increase the loft of the face at impact and clubhead droop will increase the closure of the club face at impact. No data were supplied on how much if anything this would change the clubhead closing velocity"

Although I think he's made a mistake saying clubhead droop will increase the closure of the clubface at impact because wouldn't it make the peripheral end of the clubshaft more vertical and the clubface point further right ?

But it does seem that the golf scientists have not investigated the effect on 'rate of closure' by rate of 'loft change'.

DG

PS. Goodness !  I'm still unsure about the underlined sentence above.

If I had one of those magnetic lie pointers on the sweetspot of my PW clubface and then raised the clubshaft horizontally in front of me , it would point left , so maybe my underlined sentence above is correct.

[imperfectgolfer]

DG,

You posted this image.

The clubshaft is roughly parallel to the sides of the image and it appears to be perpendicular to the imaginary ball-target line. I presume that the wrist is neutral. If one bows or cups the lead wrist under those conditions, does it not change the clubshaft angle, which then causes the clubface to close or open. In other words, it is really a "changing the clubhead path" phenomenon and not primarily a clubface orientation issue.

We know that if the desired clubhead path is "in-to-square-to-in" that if one decreases the VSP, that this clubhead path angle issue (that causes a change in clubface orienation) will become greater. So, what point are you trying to make?

Jeff.

[dubiousgolfer]

Dr Mann - I'll do my best to describe my confusion on clubface closure effect due to clubhead path.

Say for example we have 2 swings (with same club and clubhead speeds) on the same functional plane with the clubface square to the clubhead path.

1. 1st swing has a clubhead path radius similar to your TW image in the previous post (the red lined path)
2. 2nd swing has a clubhead path radius similar to CM (and lets assume it is influenced by pure lead wrist bowing towards extension from P6.5-P7.5 ) - a flipping hand release action

Will the 2nd swing have a more 'in-square-in' path than the 1st ? I can't imagine it can if its on the same functional plane.

If I imagined that magnetic pointer stuck on the clubface of the 2nd swing wouldn't it start to point left more than the 1st swing through impact? If true , then doesn't that mean the angle of clubface attack approaching the ball and its angle of exit after impact can influence rate of closure (its not just the VSP , clubhead speed and  handle twist velocity)?

DG

[imperfectgolfer]

Oct 13, 2020 19:11:20 GMT -5 dubiousgolfer said:

Dr Mann - I'll do my best to describe my confusion on clubface closure effect due to clubhead path.

Say for example we have 2 swings (with same club and clubhead speeds) on the same functional plane with the clubface square to the clubhead path.

1. 1st swing has a clubhead path radius similar to your TW image in the previous post (the red lined path)
2. 2nd swing has a clubhead path radius similar to CM (and lets assume it is influenced by pure lead wrist bowing towards extension from P6.5-P7.5 ) - a flipping hand release action

Will the 2nd swing have a more 'in-square-in' path than the 1st ? I can't imagine it can if its on the same functional plane.

If I imagined that magnetic pointer stuck on the clubface of the 2nd swing wouldn't it start to point left more than the 1st swing through impact? If true , then doesn't that mean the angle of clubface attack approaching the ball and its angle of exit after impact can influence rate of closure (its not just the VSP , clubhead speed and  handle twist velocity)?

DG

I still cannot grasp what point you are trying to make.

Regarding your bold-highlighted statements - if the lead wrist is moving towards extension, how can the radius be similar to CM's clubhead path where he maintains a bowed lead wrist all the way to impact. Also, "moving towards extension" pre-impact is not a flipping release if the lead wrist is still marginally bowed at impact.

Here is an example of flipping release through impact.

Flipping the lead wrist through impact can alter the clubhead arc and cause it to move more inside-left. That will cause the clubface to be more closed relative to the ball-target line even if the clubface remains square to the clubhead arc. If left wrist circumduction happens at the same time, then the clubface will close relative to the clubhead arc.

Jeff.

[imperfectgolfer]

One of the issues that we often discuss when addressing whether clubface closure in the early downswing affects the amount of lead forearm supination happening during a PA#3 release action in order to square the clubface by impact is the issue as to whether the lead forearm is more supinated at impact compared to address. In the absence of reliable 3D data, I have to hazard a "guess" and that involves looking at the lower lead radial bone (relative to the antecubital fossa) at impact - compared to those same alignments at address. However, this crude visual technique is potentially highly unreliable.

Consider this example - featuring Jamie Sadlowski.

Here is a comparison of his address and impact alignments.

Image 1 is at address and image 2 is at impact.

JS adopts a very strong lead hand grip, and one would imagine that he acquires that strong lead hand grip by pronating his lead forearm more before gripping the club so that his lead palm can be placed over the top of the club handle at address. His lead humerus looks internally rotated at address.

At impact, his lead humerus still looks to be internally rotated, but one cannot tell if it is the same in degree compared to address. What about his lead forearm - is it supinated more than it was at address? It does not look more supinated to me. In fact, it possibly looks slightly more pronated to a very small degree.

However, here is the true reality.

Here is his 3D graph.

Note that his lead forearm is ~75 degrees supinated at address and ~20 degrees supinated at impact. That means that his lead forearm is ~55 degrees more supinated at address - compared to impact.

How is that possible?

Look at these DTL capture images.

Image 1 and image 1a (close-up view) is at P1.2 (when I can first see his antecubital fossa from a DTL viewing perspective). 

Note that his lead humerus is rotated internally to a marked degree at address and that his lead lower radial bone is rotated counterclockwise (in a supinatory direction) relative to his lead antecubital fossa to a marked degree. In other words, when JS adopts a strong lead hand grip, he rotates his lead humerus clockwise to a marked degree so that his lead humerus is very internally rotated and he then supinates his lead forearm to get his lead palm over the top of the club handle.

At impact, image 2 shows that his lead humerus is far less internally rotated and his lead lower radial bone is rotated clockwise in a pronatory direction relative to his lead antecubital fossa.

Note that only looking at face-on capture images can totally misrepresent reality when the lead antecubital fossa is not clearly visible!

Jeff.

[dubiousgolfer]

Dr Mann - will you be producing a new You-Tube video about clubface effect caused by bowing the lead wrist?

DG


PS. With regards my previous post and my difficulties explaining my point, I tried drawing this diagram below. There are 2  club paths on the same functional plane , the black path is a longer radius while the red line path (not very well drawn)  is the shorter swing radius.   If a golfer was able to swing with a  square clubface on either path , would the rate of clubface closure be greater along the red path?

[imperfectgolfer]

Oct 15, 2020 20:50:03 GMT -5 dubiousgolfer said:

Dr Mann - will you be producing a new You-Tube video about clubface effect caused by bowing the lead wrist?

DG


PS. With regards my previous post and my difficulties explaining my point, I tried drawing this diagram below. There are 2  club paths on the same functional plane , the black path is a longer radius while the red line path (not very well drawn)  is the shorter swing radius.   If a golfer was able to swing with a  square clubface on either path , would the rate of clubface closure be greater along the red path?

The clubface closure rate should be greater on the red path if the clubhead path moves inside-left faster. It is equivalent to what happens if the VSP decreases and produces a more merry-go-round clubhead path pattern rather than a ferris wheel clubhead path pattern.

I plan to write a review paper on this topic this winter, rather than do another you-tube video, because I can use all the pro golfer examples that I have described in this thread. In the review paper, I will also correct all my mistakes that I made in my you-tube video.

Jeff.

[dubiousgolfer]

Dr Mann

I am inclined to agree with you regarding that red clubhead path line but wondering why it is not factored in within Phil Cheethams dissertation below. His equation used the variables  'swing plane velocity',  'HTV'  and the 'swing plane angle θ' .  In my example above the SPV, HTV and 'θ' (and therefore resultant CCV value) would be identical, but that seems incorrect because the red path is moving more  'in-square-in' . 





DG

PS . I asked Dave Tutelman about the above and his replies are below:

-------------------------------------
Question:  So does the instantaneous path radius also affect 'ROC' through impact?


Answer: I simply don't know. It would most likely depend on the golfer. I don't
know what the golfer did differently to make the radius of curvature
smaller for the red path. If it were a different, shorter, club, I could
talk about it. But I don't know what mechanics are involved with your
model, nor the mechanism that golfer uses to square the face and how it
interacts with whatever he is doing to shorten the radius. It would
certainly depend on these things

Question: When I read Phil Cheetham dissertation (link below page 21) , I cannot
see path radius as being a variable in his equation for ROC (he calls it
CCV).

Answer: CCV is not quite the same thing as ROC, but it is the biggest single
factor in calculating ROC. But you're right that he never deals with this.



In fact, I don't think he could. His dissertation is about how different
tour players square the clubface. Each tour player would have A SWING --
just one -- with a single radius of curvature. These players are so good
that there would probably not be much curvature variation at all from
swing to swing. So I don't know how his data could address the problem
you pose.

-------------------------------------------------------

The bolded underlined section above really surprised me , so now wondering what the real definition of ROC is and whether it relates to D -Plane (will be investigating further).


Update:
Dave Tutelman has admitted that he made a mistake and that CCV is equivalent to ROC . 

I've emailed him below about a possible relationship of ROC with 'rate of change of dynamic loft'.

--------------------------------------
I  remember an article of yours below which sort of suggests to me (although I might be completely wrong) that there could be some association with ROC related to the 'rate of change of dynamic loft' as the club approaches the ball .

www.tutelman.com/golf/swing/accelerateThru.php

The left wrist is cupped, rather than the proper flat or even bowed left wrist. We know that a bowed wrist at impact (or a flat wrist at the very least) is desirable for a solid hit. A cupped wrist, on the other hand, is associated with lost clubhead speed, fat or thin shots, or too-high balloon shots. It is also likely to point the clubface to the left, resulting in a pull or even a pull-hook. (Think about it this way: if the swing plane were perfectly vertical, then a cupped left wrist would add loft. Since the swing plane is not vertical but tilted, some of that "loft" turns into a left-facing angle.)
-----------------------------