Post by imperfectgolfer on Feb 4, 2023 13:17:35 GMT -5
Here is Milo Lines latest video relating to the topic of side-bend.
Milo demonstrates a pivot motion where he goes from a P4 position where he claims that he has a condition of left-lateral bend to a position at P4.5 - P5 (end of the hip squaring phase) where he claims that he has acquired his maximum degree of right-lateral bend. Milo also claims that the end-result of this type of pivot motion is that he is passively carrying his hands downwards towards waist level without any independent motion of the arms. Milo also claims that this side-bend pivot motion maneuver enables him to avoid an OTT move and that it enables him to slot his clubshaft in a way that it will lead to clubshaft shallowing.
Let's consider a few examples.
Back view capture images of Sergio Garcia's P4 => P5 early downswing action.
Back view capture images of Rory McIlroy's early downswing action between P4 => P5.
Note how much his arms drop between P4 => P5 and how much he adducts his trail upper arm towards his trail shirt seam.
I can see no evidence that he is moving his arms downwards between P4 => P5 as a direct result of changes in the "side-bend angles" - going from left-lateral bend to right-lateral bend in the "side-bending" manner described by Milo.
Then, note that his hand arc path becomes shallower between P5 => P5.5, and even more importantly note how his clubshaft is shallowing progressively more relative to his hand arc path during that mid-downswing time period. In fact, most of Milo's clubshaft shallowing action is happening between P5 => P5.5.
Image 1 is at P5.5, image 2 is at P6 and image 3 is at P6.5.
Milo demonstrates a pivot motion where he goes from a P4 position where he claims that he has a condition of left-lateral bend to a position at P4.5 - P5 (end of the hip squaring phase) where he claims that he has acquired his maximum degree of right-lateral bend. Milo also claims that the end-result of this type of pivot motion is that he is passively carrying his hands downwards towards waist level without any independent motion of the arms. Milo also claims that this side-bend pivot motion maneuver enables him to avoid an OTT move and that it enables him to slot his clubshaft in a way that it will lead to clubshaft shallowing.
Here is a capture image of Milo demonstrating this side-bend pivot motion maneuver.
In this image Milo is at a simulated P4.5 - P5 position where his hips have squared.
Milo states that he is in a condition of maximum right lateral bend. However, if you look at his spinal alignment in this image it looks like he has no right lateral bend of the thoracic spine relative to the lumbar spine and that allows his upper swing center to be stacked over his lower swing center. I do not dispute that Milo is applying a lot of "crunching-in" force on the right side of his mid-torso and that he is attempting to maximally compress the right side of his rib cage, which causes the distance between his right shoulder and his right pelvic crest to decrease. However, he is not achieving a significant amount of right lateral bend (defined in my way as a significant amount of rightwards tilting of the thoracic spine relative to the lumbar spine) at this time point because there are a number of biomechanical factors that are impeding his ability to get a lot of right lateral bend (relative to the lumbar spine) at this stage of the downswing - i) the presence of anterior pelvic tilt and ii) a scenario where the lower swing center is still stacked under the upper swing center. By contrast, Milo manifests a lot of right lateral bend (defined as rightwards tilting of the the thoracic spine relative to the lumbar spine) between P7 => P8 when i) his pelvis is in a condition of posterior pelvis tilt and ii) when his upper swing center is far back relative to his lower swing center due to the presence of a lot of acquired secondary axis tilt and iii) when his pelvis axis is more open than his shoulder turn axis. I think that Milo's definition of maximum right side-bend is best understood as being the maximum degree of "crunching-in" of the right side of the mid-upper torso that can be practically achieved at the P4.5 - P5 position.
Now, although I disagree with Milo's definition of maximum right lateral bend, I can clearly understand what he is doing biomechanically from a pivot motion perspective and I can clearly understand how it can cause the arms to lower between P4 => P5 in such a manner that a golfer can describe the "feel" of any arm lowering action as a being a scenario where it "feels" as if the pivot motion is lowering the arms without there being any independent motion of the arms. I can also easily accept the claim that many pro golfers (eg. Dustin Johnson) manifest that pivot motion-induced arm lowering pattern between P4 => P5.
However, I think that are other ways that pro golfers lower their arms during the P4 => P5 time period that allows them to slot the club appropriately and avoid an OTT move swing fault.
Let's consider a few examples.
Back view capture images of Sergio Garcia's P4 => P5 early downswing action.
Image 1 is at P4, image 2 is at P4.25, image 3 is at P4.6 and image 4 is at P5.
Note that SG has rotated his shoulders >90 degrees during his backswing action and that he appears to be leaning leftwards. I can therefore accept a claim that SG is arch-extending his upper thoracic spine at P4, but I do not believe that he has a significant degree of left-lateral bend of his spine (in the sagittal plane) at P4, which would theoretically cause his shoulder turn angle to become steeper (when viewed from DTL). When viewed from DTL, SG's shoulder turn angle is relatively horizontal in his "real life" driver golf swing action.
Note how much he is lowering his hands between P4 => P5 and note how much he is adducting his trail upper arm towards the trail side shirt seam. Note that there has been very little counterclockwise rotation of his upper torso during that time period so his upper back is still facing the target at P5, and there has been a negligible amount of lowering of his right shoulder due to compression of the right side of his mid-upper torso as a result of a "crunching-in" of the rib cage action (as described by Milo).
I personally think that his arm lowering action between P4 => P5 is significantly due to an independent arm motion, and that it is not primarily pivot-driven (in the "side-bending" manner described by Milo).
Back view capture images of Henrik Stenon's early downswing action between P4 => P5.
Image 1 is at P4, image 2 is at P4.5 and image 3 is at P5.
I think that HS manifests a rightwards-centralised upper torso loading pattern and that he does not exhibit any arch-extension of his upper thoracic spine at P4 (like Sergio Garcia) or any left-lateral bending of his thoracic spine that would steepen his shoulder turn angle at P4.
Note how much HS is lowering his hands, and how much he is adducting his trail upper arm towards his trail side shirt seam, between P4 => P5 with only a small amount of lowering of his right shoulder socket. I do not think that HS is trying to maximally "crunch-in" the right side of his mid-torso and maximally bend the right side of his rib cage - as described, and demonstrated, by Milo Lines in his video. Note that HS's upper back is still facing the target at P5 (in a similar manner to SG) and I think that is very difficult from a biomechanical perspective to maximally "crunch-in" the right rib cage when the upper torso is still so closed during the P4 => P5 time period even if the hips have squared due to a lot of torso-pelvic separation motion (dynamic X-factor motion) happening during the P4 => P5 time period. I think that HS's right shoulder lowering motion seen between P4 => P5 is mainly due to scapular motion with only a small amount of "crunching-in" of his right chest rib cage happening during that same time period.
I therefore think that HS's arm-lowering motion, which allows him to successfully slot the club, is partially due to an independent arm motion and not primarily due to a pivot-driven "side-bending" motion.
Back view capture images of Rory McIlroy's early downswing action between P4 => P5.
Image 1 is at P4, image 2 is at P4.25, image 3 is at P4.5 and image 4 is at P5.
Note that RM has a vertical-centralised upper torso loading pattern at P4, which means that he has an element of arch-extension of his thoracic spine plus a small degreee of left-lateral bend.
Note how he squares his pelvis between P4 => P5 but he has very little "crunching-in" compression of his right mid-upper torso. Note how his upper back is still facing the target at P5. Note that he has no evidence of right lateral bend of his thoracic spine (relative to his lumbar spine) at P5.
Note how much his arms drop between P4 => P5 and how much he adducts his trail upper arm towards his trail shirt seam.
I can see no evidence that he is moving his arms downwards between P4 => P5 as a direct result of changes in the "side-bend angles" - going from left-lateral bend to right-lateral bend in the "side-bending" manner described by Milo.
I think that his lead arm's lowering action is partially due to his pivot motion - due to the fact that as his upper torso rotates counterclockwise the left shoulder socket is moving targetwards and that will pull the lead upper arm's humeral head along - and because the lead upper arm is angled near-vertical at P4 it will descend to a more horizontal alignment if the left humeral head is being pulled targetwards by the rotating lead shoulder socket. Another major factor that potentially causes the left upper arm to move downwards, rather than outwards in an OTT manner, is the fact that he is adducting his trail upper arm at the same time while maintaining a bent trail elbow. Note how his trail forearm is angled near-vertical at P4 and it then becomes near-horizontal by P5 while he keeps his upper back facing the target and while he avoids rotating his trail shoulder outwards in the direction of the ball-target line (which predisposes a golfer to an OTT move).
If you watch Milo performing his "side-bend" move between the 5:20 - 6:20 minute time points of his video, he shows how he gets his hands/club down to waist level as a result of his pivot motion that incorporates a very high degree of squatting motion, and he infers that his arms/club are being passively pulled down to a P5.5 position as a result of the pivot motion rather than as a result of any independent arm motion. Note how he keeps his lead upper arm closely adducted against his upper chest during his demonstration where he is implying that his pivot motion is "carrying" his arms down to waist level. However, that does not happen in his "real life" golf swing action.
Consider Milo Lines's driver golf swing action.
Here are capture images of his driver golf swing's early-mid downswing action.
Image 1 is at P4, image 2 is at P4.5, image 3 is at P5, image 5.2 and image 5 is at P5.5.
The red splined path is his hand arc path. Note that his hand arc path is fairly steep between P4 => P5 and that there is very little shallowing of his clubshaft (relative to his hand arc path) during that P4 => P5 time period.
Note that there is very little change in his degree of lead arm adduction between P4 => P5 so it is reasonable to accept the "idea" that his pivot motion is pulling his arms along without there being any independent arm action happening during his early downswing action between P4 => P5.
Then, note that his hand arc path becomes shallower between P5 => P5.5, and even more importantly note how his clubshaft is shallowing progressively more relative to his hand arc path during that mid-downswing time period. In fact, most of Milo's clubshaft shallowing action is happening between P5 => P5.5.
What is the major biomechanical factor causing clubshaft shallowing during the P5 => P5.5 time period?
I believe that it is primarily due to an arm action - specifically relating to biomechanical actions happening with respect to his trail arm/forearm.
Note that Milo's lead arm is moving rapidly towards abduction between P5 => P5.5 and that represents the pivot-induced release of PA#4 (release of the lead arm) which is causally responsible for most of a pro golfer's swing power. It has been shown that the lead hand speed of most pro golfers reaches its peak speed at ~P5.5 secondary to the release of PA#4.
What causes his hand arc path to become more horizontal between P5 => P5.5?
I believe it is mainly due to the fact that his right forearm is becoming more horizontal between P5 => P5.5 due to a progressively partial-straightening action of his trail elbow where his right forearm is simultaneosuly being angled well to the right.
What causes his right forearm to be angled to the right, in an away from a target direction, in image 5?
I think that it is mainly due to the fact that he is performing a pitch elbow motion of his right elbow where his right elbow lead his right hand in its downplane directional travel direction, and where his right elbow moves from a position where it is alongside his trail shirt seam at P5 (image 3) to become positioned in front of his right hip joint area at P5.5 (image 4). Note how the lower end of his trail upper arm becomes angled towards the target at P5.5, which then produces a small degree of external rotation of his trail humerus.
Image 1 is at P5.5, image 2 is at P6 and image 3 is at P6.5.
Note that I have drawn a red line down the length of his trail upper arm. Note that the lower end of his trail upper arm is angled towards the target at P5.5 and that his trail elbow is in front of his right hip area. I have drawn a yellow line along the length of his trail forearm - note that it is angled to the right and not straight-in-line with his trail humerus (see blue line) which means that his trail humerus is externally rotated.
If a golfer performs a pitch elbow motion of the right arm and simultaneously ensures that the right humerus is externally rotating during the partial right elbow straightening action that is happening between P5 => P5.5 that will cause the right palm to become more horizontal relative to the ground and that will cause the hand arc path to become shallower between P5 => P5.5.
What causes the clubshaft to become more shallow relative to his hand arc path between P5 => P5.5 in Milo's golf swing action?
I believe that it is due to the combined effects of the biomechanical combination of i) right forearm supination that is combined with ii) a small degree of external rotation of the right humerus.
Here - for comparison purposes - is Rory McIlroy's clubshaft shallowing action.
Image 1 is at P4, image 2 is at P4.5, image 3 is at P5 and image 4 is at P5.5.
Note that Rory's clubshaft is shallowing relative to his hand arc path between P5 => P5.5, but not to the same degree as Milo's. Note how Rory keeps his right upper arm glued to his trail shirt-seam all the way between P5 => P5.5, which means that he is not externally rotating his right humerus during that time period. Note how his right forearm is angled more downwards at P5.5 (image 4) as he partially straightens his right elbow. However, his trail forearm is not as horizontal as Milo's trail forearm at P5.5 and his trail palm is not as horizontal, which means that he manifests slightly less clubshaft shallowing action between P5 => P5.5 compared to Milo.
Finally, I want to discuss the topic of chest side-bend as measured by the GEARS 3D-system.
Milo discusses the chest side-bend measurements of Dustin Johnson as measured by the GEARS 3D-system between the 1:46 - 3:18 minute time point of the video. Note that the orange graph shows a chest side-bend angle of 45 degrees to the right at P5.5 where it reaches its maximum amount and the orange graph then shows that this chest side-bend angle decreases by ~15 degrees between P5.5 => P7. I would like Milo to explain how this chest side-bend angle is measured and how it relates to my measurement of right lateral bend of the thoracic spine relative to the lumbar spine. I have shown that DJ's right lateral bend starts increasing between P5 => P5.5 and that it increases more between P5.5 => P7 and that there is a positive correlation between the degree of right lateral bending and the steepness of the shoulder turn angle happening between P5.5 => P7. I would like to better understand how GEARS measures chest side-bend and how it relates to simultaneous measurements of i) right lateral bend and ii) the shoulder turn angle between P5.5 => P7.
Jeff.
