Comparing a DH to a non-DH hand

In this post I am going to mainly talk about the differences between a DH-hand release action and a flipping subtype of non-DH hand release action with respect to their different biomechanics. Originally, I was just going to analyse my friend's opinion that the likely cause of a DH-hand release action is due to a delayed release of the club (= delayed release of PA#2) in this post, but I finally decided to extensively review my reformulated opinions regarding two topics- i) my revised definition of a DH-hand release action, and ii) my revised opinions with respect to whether the two different hand release actions can have a major effect on a golfer's ability to generate a straight ball flight.

In the past I have defined a DH-hand release action as being present if the clubshaft does not bypass the lead arm (from an angular rotational perspective) during the early followthrough time period between P7 => P7.2, which usually results in the clubface being square relative to the hand arc path during that early followthrough time period. I have also inferred that the main reason that enables a golfer to perform a DH-hand release action is their ability to ensure that the targetwards momentum of the lead arm is perfectly matched relative to the acquired forward/targetward momentum of the released club during that early followthrough time period. Many pro golfers, who perform a DH-hand release action between P7 => P7.2 (or even further to P7.4), also maintain a bent (extended) trail wrist during that early followthrough time period even though it is not an obligatory requirement in my definition of a DH-hand release action. I have also stated that their is no mandatory causal connection between what happens pre-impact in terms of the biomechanics causing the efficient release of PA#2 (release of the club) and the efficient release of PA#3 (which is due to lead forearm supination) and the post-impact biomechanics causing the efficient execution of a DH-hand release action. My friend, Jim George, has a different personal perspective, and he believes that it is artificial to separate the release phenomenon into a pre-impact phase and a post-impact phase because he thinks of the release of the club as being a single golf swing biomechanical phenomenon (singular set of biomechanical actions) that starts at the release point and continues through impact to the end of the followthrough (or to at least P7.4+). He also hypothesised that a DH-hand release action is most likely due to a delayed release of the club while a non-DH release action is due to a non-delayed (standard) release of the club. In other words, he hypothesised that the timing of the release of the club is the major factor that causes a DH-hand release action versus a non-DH hand release action through impact. I decided to test his hypothesis by more thoroughly comparing the hand release actions of a large number of pro golfers and I will present some of their release actions in this post in order to demonstrate why I believe that his hypothesis is not supported by the "real life" reality of the hand release actions of many pro golfers.

To start off, I have to define what represents a non-delayed (standard) release of the club versus a delayed release of the club (= release of PA#2 in TGM terminology). The release of the club is due to lead wrist ulnar-deviation that causes the angle between the club and the lead arm to start to increase during the downswing (in the plane of lead wrist radial => ulnar deviation and where that release plane is usually parallel to the swingplane if the clubshaft is always on-plane during the entire downswing action). Most pro golfers have at least a roughly ~90 degree angle between the lead arm and the clubshaft at P4 and it is often referred to as the clubshaft lag angle. The club release action happens when that angle start to increase during the mid-downswing, starting usually between P5.2 => P5.5 and that would represent a non-delayed (standard) release pattern.. If the club starts to release before P5.2, I would be inclined to refer to that release pattern as an early release pattern and if it starts to release after P5.5 then I would be inclined to refer to it as a delayed release pattern. For comparison purposes, I am going to arbitraily compare different pro golfers start-of-the-release patterns at P6 when the clubshaft is parallel to the ground because all pro golfers will reach this same P6 time point where the clubshaft is parallel to the ground.

What I have noted is that most pro golfers (who perform a non-delayed/standard release action) will likely reach the P6 time point with their lead hand either just outside their trail thigh or opposite the outer half of their lead thigh, and their lead arm will be angled across the front of their chest at a ~45 -60 angle relative to the ground (or relative to the clubshaft which is parallel to the ground). By contrast, pro golfers who use a delayed release pattern, will likely have their lead hand opposite their mid-trail thigh or opposite the inner half of their trail thigh, or even just inside their lead thigh, at P6; and their lead arm will be angled >60 degrees relative to the ground.

Here are two examples of pro golfers who use a delayed release action.

Example number 1: Cameron Champ's delayed release action.

Image 1 is at P6, image 2 is at P6.5, image 3 is at P7 and image 4 is at ~P7.4.

Note that I have drawn a yellow line along the front of his lead hand at P6 and it is inside his trail thigh. Also, note that his lead arm is angled at a ~80 degrees relative to the ground at P6. Those two features allows me to classify his club release action as being a delayed release action.

Note that I have drawn a green line at the front of his lead hand position at P6.5, a red line opposite the front of his lead hand position at impact and a blue line opposite the front of his lead hand position at P7.4. Looking at these lines allows one to roughly assess where his lead hand is positioned relative to the ball during his release action. Note that his lead hand has almost reached the ball by P6, and that his lead hand is already bypassing the ball at P6.5. By impact, his lead hand is well ahead of the ball, which allows him to have forward shaft lean at impact. Note that his lead hand is well ahead of the outer border of his lead thigh at P7.4. Note that he is performing a DH-hand release action between P7 => P7.4 and that he has maintained a bent trail wrist all the way between P7 => P7.4. This DH-hand release pattern is compatible with my friend's hypothesis that a delayed club release action will result in a DH-hand release action during the early followthrough time period.

Example number 2: Dustin Johnson's delayed release action.

Image 1 is at P6, image 2 is at P6.5, image 3 is at P7 and image 4 is at ~P7.4.

Note that I have drawn a yellow line along the front of his lead hand at P6 and it is opposite his mid-trail thigh. Also, note that his lead arm is angled at a ~70 degrees relative to the ground at P6. Those two features allows me to classify his club release action as being a delayed release action. Note that his lead hand is ~4 - 6" behind the ball position at P6, which gives his lead hand an opportunity to travel more distance between P6 => ball position (compared to Cameron Champ) during his late downswing. Note that his lead hand reaches the ball position by P6.5 and it is well ahead of the ball at impact, which allows him to have forward shaft lean at impact. Note that his lead hand is well ahead of the outer border of his lead thigh at P7.4. Note that he is performing a DH-hand release action between P7 => P7.4 and that he has maintained a bent trail wrist all the way between P7 => P7.4. This DH-hand release pattern is compatible with my friend's hypothesis that a delayed club release action will result in a DH-hand release action during the early followthrough time period.

Another pro golfer who use a delayed release action is Joaquin Niemann, and he also performs a DH-hand release action between P7 => P7.4. I do not know of any pro golfer who does not perform a DH-hand release action if he uses the delayed release action technique. If you know of an example, please let me know.

However, the hypothesis that a pro golfer, who uses a non-delayed/standard release action, will always perform a non-DH hand release action is invalid because there are many examples of pro golfers, who are DHers, that use the non-delayed/standard release action. I will present two comparative examples in this post. When making a comparison, I decided to not use pro golfers who use a very strong lead hand grip because that predisposes them to having a lot of forward shaft lean at impact, which may cause them to favor using a DH-hand release action post-impact. I also decided to take ball position into account and in my two comparisons I will make sure that the ball position is roughly the same.

Comparison example number 1-: Scottie Scheffler and Will Zalatoris. Both of those pro golfers place their ball very close to their lead foot when hitting a driver and both of them use a weak lead hand grip and a neutral/weak trail hand grip.

Capture images of Scottie Scheffler's non-delayed/standard release action.

Image 1 is at P6, image 2 is at P6.5, image 3 is at P7 and image 4 is at P7.4.

Note that I have drawn a yellow line just in front of his lead hand at the P6 position (image 1), a green line just in front of his lead hand at his P6.5 position (image 2), a red line just in front of his lead hand at the P7 position (image 3), and a blue line just in front of his lead hand at the P7.4 position (image 4).

Note that the yellow line is just outside his trail thigh at P6, which means that he is using a non-delayed/standard release action. Note that his lead hand is opposite the ball at impact and that he has no forward shaft lean at impact. Note that he has a large lead hand travel distance between the yellow line and the red line to successfully complete his sequential release of PA#2 => PA#3. Note that his lead hand has travelled ~50% of that lead hand travel distance at P6.5. Note that his lead hand is still moving targetwards between P7 => P7.4 and there is no obvious stalling of the forward motion of his lead hand during the early followthrough time period between P7 => P7.4. Note that the clubshaft is bypassing his lead arm (from an angular rotational perspective) during his early followthrough, and that he is therefore using a non-DH hand release action post-impact. Note that he has a slightly bent trail arm and slightly bent trail wrist at P7, and also at P7.4 (but to a lesser degree). Note that he is using a puck release action ( a term coined by Nick Bradley) where his trail palm remains partially under/behind his club handle through impact and he does not roll his trail palm over his lead hand during the P7 => P7.4 time period.

Here is a capture image of a puck release action - captured from Nick Bradley's book called "The 7 Laws of the Golf Swing".

Image 1 is at P6, image 2 is at P7, image 3 is at P7.4, and image 4 is at P8+.

Note that the trail wrist is bent at P7, and that it straightens partly or fully by P7.4. However, the trail palm does not roll over the trail hand (which is extending by a small amount) during the P7 => P7.4 time period. Note that the clubshaft is bypassing his lead arm (from an angular rotational perspective) between P7 => P7.4 while the lead wrist is increasingly extending, which allows me to classify the puck release action as being a flipping subtype of non-DH hand release action. If there is a significant amount of lead forearm supination simultaneously happening during the early followthrough time period between P7 => P7.4, then I would classify that type of non-DH hand release action as being a flip-rolling subtype of non-DH hand release action.

Note that Scottie Scheffler is performing a flipping subtype of non-DH hand release action during his early followthrough, and not a flip-rolling subtype of non-DH hand release action.

Capture images of Will Zalatoris' non-delayed/standard release action.

Note that both Scottie Scheffler and Will Zalatoris have to use a lot of lead forearm supination between P6.5 => P7 to complete their PA#3 release action so that the back of their lead hand can face the target at impact, which causes their clubface to be square at impact. Note that they both also succesfully complete their release of PA#2 so that the clubshaft catches-up to their lead arm by impact. I can see no significant differences in their biomechanical movements responsible for the successful completion of their release of PA#2/PA#3 during the pre-impact phase between P6 => P7 - even though the biomechanics responsible for their personal post-impact hand release action are slightly different.

What is Will Zalatoris doing differently from a biomechanical perspective that allows him to perform a DH-hand release action (no-roll subtype) post-impact between P7 => P7.4?

I think that a major difference is that Will Zalatoris has a much more active pivot motion that gets his pelvis and upper torso more open at impact. His more active pivot motion (involving a significant degree of right lateral bend) also allows his trail shoulder to get further downplane by P7.4, which allows him to avoid a "running-out-of-trail arm" phenomenon, which would more likely result in a variably greater degree of straightening of his trail arm/wrist before P7.4. It looks like he is actively moving his lead arm targetwards during the P7 => P7.4 early followthrough time period and that he is not stalling the forward motion of his lead arm through impact - but he is not using a handle-dragging technique (which can markedly decrease a pro golfer's ablity to maximise his clubhead speed at impact). All these biomechanical features, which are often seen in a pro golfer who uses the no-roll subtype of DH-hand release action, have to be pre-progammed by a pro golfer before he initiates his downswing action.

What causes Scottie Scheffler's clubshaft to bypass his lead arm during the P7 => P7.4 time period? I strongly suspect that it is simply due to the fact that there is a small degree of mismatch between the forward momentum of his lead arm relative to the acquired/gained forward momentum of his clubshaft and that it is not due to any active trail hand slap-hinge action, where the trail hand is applying a positive push-pressure (positive trail hand couple torque) against the aft side of the clubshaft below the coupling point (mid-hands point) in the later downswing just before impact. Why do I harbor this belief that any trail wrist straightening action seen through impact, or seen soon after impact between P7 => P7.4, in Scottie Scheffler's driver golf swing action is passive and not active?

I am going to use Rory McIlroy's driver swing action (which is nearly identical to Scottie Scheffler's driver swing action) as an example because I already have the relevant capture images needed to present my argument.

Here are capture images of Rory McIlroy's P6 => P7.4 time period when swinging a driver.

Image 1 is at P6, image 2 is at P6.5, image 3 is at P7 and image 4 is at P7.4.

Note that I have drawn a yellow line just in front of his lead hand at the P6 position (image 1), a green line just in front of his lead hand at his P6.5 position (image 2), a red line just in front of his lead hand at the P7 position (image 3), and a blue line just in front of his lead hand at the P7.4 position (image 4).

Note that Rory's lead hand is opposite the outer half of his lead thigh at P6, which indicates that he is using a non-delayed/standard release action.

Note that his lead hand nearly reaches the ball position at P6.5, which gives him less lead hand travel distance to complete his release of PA#3 by impact. However, because he uses a moderately strong lead hand grip he does not have to use much lead forearm supination between P6.5 => P7, and he has no problem getting his clubface to become square by impact.

Note that his lead hand is roughly straight-in-line with his ball position at impact, and he has minimal forward shaft lean at impact.

Note that he maintains the forward momentum of his lead hand between P7 => P7.4, and he only manifests a small degree of clubshaft flipping when he performs a flipping subtype of non-DH release action during his early followthrough. Note that he maintains a small degree of trail arm bend and trail wrist extension all the way to P7.4 and he is not "running-out-of-trail arm".

Note that he is performing a puck release action through impact, and not a roller release action where the trail palm rolls over the lead hand soon after impact (due to trail forearm pronation).

Note the remarkable similarity (from a biomechanical perspective) between Scottie Scheffler's and Rory McIlroy's hand release action through impact.

Note that there is no evidence to suggest that Rory McIlroy is using an active slap-hinge release action due to his trail hand applying a positive push-pressure against the aft side of the club handle below the coupling point through impact. Note that his peripheral clubshaft is bent forward at P6.5 and at P7, which suggests that he has a negative trail hand couple phenomenon (negative alpha torque phenomenon) happening during his late downswing and through impact.

Here is another series of capture images of Rory McIlroy's driver swing action.

Image 1 is at P4, image 2 is at P5, image 3 is at P5.5, image 4 is at P6 and image 5 is at P6.4.

I have drawn a yellow line along his proximal clubshaft. Note that his entire clubshaft forms a straight line with that yellow line at his P4 position, which means that no alpha torque is being exerted at this time point.

Note that his peripheral clubshaft is bent back a lot at P5 and to a lesser degree at P5.5, which means that he is applying a positive alpha torque during his early-mid downswing between P4 and P5.5.

However, note that his clubshaft is marginally bent forward at P6 and significantly bent forward at P6.4 (and it remains bent forward all the way to impact). This means that the change from having a positive alpha torque to having a negative alpha torque happens around P5.5 - P6 and one can reasonably conclude that Rory McIlroy is applying a positive alpha torque during the "swing power generation phase" of his downswing between P4 and P5.5 (as a result of his pivot-induced release of PA#4) and that his club then releases (due to the physics causing the release of PA#2) starting between the P5 => P5.5 time point of his downswing. During his later downswing, his peripheral clubshaft is traveling faster than his proximal clubshaft as a result of the forces causing the release of PA#2 and one can reasonably conclude that he is not applying any push-pressure against the aft (back) side of the club handle with his trail hand (operating as a positive trail hand couple) in order to make it travel faster at any time point during his later downswing.

The two renown biomechanists (Dr. Kwon and Sasho MacKenzie) and a golf physicist (David Tutelman) have all agreed that a positive trail hand couple phenomenon does not exist during the late downswing and/or at impact in pro golfers, but a fair number of golf instructors believe that a pro golfer is applying a positive push-pressure against the aft side of the club handle below the coupling point during the later downswing and at impact. For example, Terry Rowles and Mike Adams believe that a pro golfer, who uses an on-top (weak) trail hand grip (which they refer to as a face-opener grip), should be applying a positive push-pressure with the trail hand starting in the early downswing in order to apply what they perceive to be a necessary clubface-closing action that is needed to counteract the face-opening influence of a weak trail hand grip.

Here is a capture image of Terry Rowles demonstrating a drill where he uses a swim-paddle mitt on his trail hand to demonstrate how an on-top golfer should have his trail palm facing groundwards so that he can apply a positive push-pressure against the aft side of the club handle during the mid-late downswing action.

Here are capture images of Mike Adams using a swim paddle mitt on his trail hand.

Note how Mike Adams is using his trail hand to push against the aft side of the club handle below the coupling point and how he eventually rolls his trail hand over an extending trail hand after impact.

Terry Rowles and Mike Adams not only believe that an on-top golfer should be applying a push-pressure against the aft side of the club handle during the mid-late downswing, but they seemingly also believe that the golfer should continue to apply that push-pressure through impact.

Watch the following video of Mike Adams giving a lesson to an "on-top" golfer.

https://vimeo.com/244953449/d28a95cd1f?fl=pl&fe=cm

Watch the video between the 8:24 - 8:48 minute time points.

Note that Mike Adams wants that golfer to follow through more inside-left after impact in order to correct his excessive in-to-out clubhead path at impact. Note that he instructs the golfer to apply push-pressure with his trail hand against the aft side of the club handle below the coupling point.

Now, if Terry Rowles and Mike Adams want to teach their student-golfers (who use an on-top trail hand grip) to apply a positive push-pressure against the aft side of the club handle below the coupling point during the late downswing, and through impact, then they are obviously free to teach that golf swing technique; but where is the scientific evidence that pro golfers (who use an on-top trail hand grip like Scottie Scheffler and Rory McIlroy) are using a positive trail hand couple torque during the late downswing and at impact? I have never seen Terry Rowles and Mike Adams present any scientific evidence that shows that Scottie Scheffler and Rory McIlroy are applying a positive trail hand couple torque ( = push-pressure against the aft side of the club handle below the coupling point) during the late downswing and at impact. I think that Terry Rowles should get together with Phil Cheetham and Sasho MacKenzie to perform a golf research study where they place pressure sensors on the aft side of the club handle just below the coupling point, so that they can actually measure the precise amount of push-pressure that is being exerted by the trail hand during the late downswing, and at impact, in pro golfers who use an on-top trail hand grip.

There is another belief that Terry Rowles promotes in a golfer who uses an on-top (weak) trail hand grip. Because Terry Rowles believes that a weak trail trail hand grip is a face-opener grip, he believes that the golfer should start his trail arm/hand clubface-closing action sooner. When Terry Rowles talks of the trail upper limb performing a clubface-closing action, he uses the analogy of a boxing punch action - as seen in the following capture image.

Image 1 shows Terry Rowles with a flexed trail elbow and he is ready to perform a punch action.

Image 2 shows him performing the punch action by fully straightening his trail arm. Note how his trail fist rotates ~90 degrees counterclockwise secondary to a trail forearm pronatory motion.

Terry Rowles seemingly believes that the trail arm must fully straighten and that the trail forearm must subsequently pronate during the later downswing and through impact in a golfer who uses an on-top (weak) trail hand grip - as demonstrated in the following capture images.

These capture images are derived from a video where Terry Rowles demonstrates how different strengths of trail hand grip affect the motion of his trail hand through impact.

Note how his use of an on-top trail hand grip supposedly causes his trail palm to roll over his extending lead hand through impact secondary to a trail forearm pronatory motion (image 1) and I refer to that type of hand release pattern as a rolling hand release pattern or a hand-crossover release pattern; while an under (strong) trail hand grip supposedly results in a puck release pattern, where the trail palm works under the lead hand through impact (image 2). In the side-on variation (image 3), note that he is still performing a puck release pattern, but his trail hand is more behind the club handle rather than being more under the club handle.

As I have demonstrated, both Rory McIlroy and Scottie Scheffler perform a puck release pattern (that is similar to image 3) and they do not perform a rolling hand release pattern, which Terry Rowles recommends for an on-top golfer (as seen in image 1). Also, note that they do not stall the forward motion of their lead arm/hand through impact - as seen in those capture images of Mike Adams and Terry Rowles performing a rolling hand release action. My conclusion is that those two pro golfers are therefore not performing a golf swing action in the manner recommended by Terry Rowles. I believe that Rory McIlroy and Scottie Scheffler are using a pivot-induced TGM swinging action (lead arm swinging action) golf swing technique, while Terry Rowles in his video demonstration is using a different golf swing technique where he actively uses his trail arm to execute his personal golf swing action.

Watch this Terry Rowles video where he demonstrates his on-top golf swing action - x.com/GOLF_com/status/1385009350985539585

Note that he states that he believes that the trail hand controls the clubface, and at the 2:02 - 2:20 minute time point of the video he shows a drill where he opens the clubface by 15 degrees and then tries to hit the ball straight.

Here are capture images of his hand release action through impact.

Image 1 is at P7 and image 2 is at ~P7.7.

Note how he is not performing an active pivot motion to release his lead arm (release PA#4) during his early-mid downswing and note that his pelvis/upper torso are facing the ball-target line at impact. Note that he is stalling the forward motion of his lead arm through impact. Note how he fully straightens his trail arm and pronates his trail forearm through impact.

Those two capture images are from a drill, while here is a capture image from his full golf swing action that he performs at the end of the video.

Note how he is fully straightening his trail arm and trail wrist through impact.

However, note that his pattern of hand release action through impact actually looks more similar to the puck release pattern of hand release action performed by Scottie Scheffler and Rory McIlroy in the sense that he is not stalling the forward motion of his lead arm as much at impact (compared to his drill golf swing action), and he is not performing a hand cross-over (roller release) type of hand release action through impact. However, note that his trail forearm is more pronated at P7.4 - compared to Scottie Scheffler's and Rory McIlroys trail forearm at their P7.4 position. So, it is theoretically possible that his trail hand is actively performing a slap hinge type of hand release action through impact. That is why I would very much like to see Terry Rowles perform a golf research study using pressure sensors that are placed on the aft side of the club handle just below the coupling point - in order to determine whether he is applying more push-pressure with his trail hand against the aft side of the club handle during the P6 => P7.4 time period in his drill golf swing action versus his "real life" full golf swing action; and whether there is a difference in his "real life" full golf swing action's pressure sensor measurements compared to Scottie Scheffler's and Rory McIlroy's pressure sensor measurements.

Comparison number 2-: Louis Oosthuizen and Viktor Hovland. Both of those pro golfers use a moderately strong trail hand grip and they both place their ball further back towards the middle of their stance in their driver swings.

Capture images of Louis Oosthuizen's non-delayed/standard release action.

Image 1 is at P6, image 2 is at P6.5, image 3 is at P7 and image 4 is at P7.4.

Note that I have drawn a yellow line just in front of his lead hand at the P6 position (image 1), a green line just in front of his lead hand at his P6.5 position (image 2), a red line just in front of his lead hand at the P7 position (image 3), and a blue line just in front of his lead hand at the P7.4 position (image 4).

Note that the yellow line is just reaching the outer border of his trail thigh at P6, which means that he is using a non-delayed/standard release action. Note that his lead hand reaches the ball position by P6.5, which gives him less lead hand travel distance to complete his PA#3 release action by impact. However, he uses a moderately strong lead hand grip, so he does not have to use much lead forearm supination during his PA#3 release action. Note that his lead hand is marginally ahead of the ball at impact, which allows him to have forward shaft lean at impact. Note that his lead arm continues to move targetwards between P7 => P7.4 by a large amount and that he is not allowing the clubshaft to bypass his lead arm (from an angular rotational perspective), which means that he is performing a DH-hand release action. Note how he maintains a bent trail arm and a very extended trail wrist all the way to P7.4 - and that is only physically possible because he avoids a "running out of trail arm" scenario by executing a very active pivot motion that gets his pelvis/upper torso to become very open at impact and where his trail shoulder socket moves very far downplane by P7.4.

I think that the biomechanical explanations that account for the differences in Louis Oosthuizen's flipping subtype of non-DH hand release action versus Viktor Hovland's DH-hand release action are the same as the biomechanical explanations that I provided in my explanation of the differences seen in Scottie Scheffler's flipping subtype of non-DH hand release action versus Will Zalatoris' DH-hand release action - so I will not repeat the explanations.

Note that both Louis Oosthuizen and Viktor Hovland use a non-delayed/standard release action, and not a delayed release action, thereby disproving my friend's hypothesis about the timing of the release action and the subsequent pattern of hand release action happening between P7 => P7.4.

Louis Oosthuizen's i) lead arm does not move as assertively through impact and ii) he also has a greater degree of trail arm/trail wrist straightening at P7.4 compared to Scottie Scheffler - even though they both perform a flipping subtype of non-DH-hand release action. However, I still strongly suspect that both pro golfers are not using an active slap hinge release action through impact and that Louis Ooosthuizen's greater degree of trail arm/trail wrist straightening phenomenon through impact is passive (and not active). I would very much like to see a golf researcher perform my recommended golf research study using preesure sensors placed on the aft side of the club handle just below the coupling point in order to determine whether the trail hand is applying any positive push-pressure against the aft side of the club handle between P6 => P7.4 in pro golfers (like Louis Oosthuizen) who perform a greater degree of flipping in their flipping subtype of non-DH hand release action.

Finally, I would like to discuss two topics - i) my revised definition of a DH-hand release action and ii) the question as to whether a pro golfer who uses a DH-hand release action can hit the ball more consistently straight than a pro golfer who uses a non-DH hand release action.

I first published my opinions regarding a DH-hand release action in 2012 in this review paper - www.perfectgolfswingreview.net/HandRelease.htm

I now think that I got many things wrong. At the time, I believed that there was an advantage to keeping the clubface square relative to the hand arc path from P7.0 => P7.2 by preventing the clubshaft from bypassing the lead arm (from an angular rotational perspective) during that early followthrough time period, which I then used to define a DH-hand release action. I then divided DH-hand release actions into two subgroups - i) a no-roll subtype (as seen in the DH-hand release actions of Will Zalatoris and Viktor Hovland) and ii) a delayed full-roll subtype (as seen in the driver golf swing actions of pro golfers like Ernie Els and Tiger Woods)..

As an example of a delayed full-roll subtype of DH-hand release action, I used the driver golf swing action of Ernie Els.

Here is an animated gif of Ernie Els driver golf swing action.

Note that he has a FLW at impact and also in the first-and-second animated images immediately after impact (which are roughly at the P7.1 and P7.2 positions) where his clubshaft has not significantly bypassed his lead arm (from an angular rotational perspective). I therefore labelled his hand release action as being a DH-hand release action. However, if you look at his overall pivot motion and his overall pattern of lead/trail arm motion through impact, it is basically identical to that manifested by Scottie Scheffler and Rory McIlroy. Note that he is performing a puck release type of hand release action through impact and note that his clubshaft is bypassing his lead arm (from an angular rotational perspective) by a significant amount between P7.2 => P7.4 and note how his trail arm/wrist straightens fully by P7.4. The only difference is the timing of his clubshaft flipping motion where it does not appear to be significantly bypass-flipping relative to his lead arm at P7.2 (which is my arbitrary/unscientific point of defining a DH-hand release action). However, if one examines multiple examples of Rory McIlroy's driver golf swing action, one can find that the timing and the degree of his clubshaft flipping motion post-impact varies and it can sometimes be defined as being a DH-hand release action (delayed full-roll subtype) even though the underlying biomechanics in terms of his pivot motion and his pattern of lead/trail arm motion between P7 => P7.4 is the same. I have therefore decided to regard a delayed full-roll subtype of DH-hand release action as being the same as the flipping subtype of non-DH hand release action from a biomechanical perspective, where the only difference is the amount of the clubshaft flipping motion present at the arbitrary P7.2 time point.

When I now think of a DH-hand release action, I now only think of the no-roll subtype where the trail arm and trail wrist remain partially bent all the way to P7.4 and where the clubshaft does not bypass the lead arm (from an angular rotational perspective) before P7.4 - as seen in the capture images of Cameron Champ's, Dustin Johnson's, Will Zalatoris' and Viktor Hovland's early followthrough action. I also used to previously believe that the advantage of a no-roll subtype of DH-hand release action is that it allows a pro golfer to more consistently keep the clubface square relative to the clubhead path throughout the entire P7 => P7.4 early followthrough time period. I still think that my belief is true, but irrelevant in terms of consistently hitting a straight shot because there is no scientific evidence that demonstrates that keeping the clubface square relative to the clubhead path for longer than a few inches post-impact is advantageous. To hit the ball consistently straight with a driver a pro golfer must zero-out the clubhead path and zero-out the clubface angle at impact and hit the ball with the clubface's sweetspot. What happens at P7.2, or P7.4, in terms of the clubface's degree of squaring relative to the clubhead path is irrelevant.

Consider yet again these capture images of Louis Oosthuizen's flipping subtype of non-DH hand release action.

Note that he has a high degree of clubshaft flipping at P7.4 (image 4) and note that his clubface is not square relative to his clubhead path.

However, that fact is irrelevant with respect to his ability to consistently generate a straight ball flight.

Consider his clubface motion immediately post-impact.

Image 1 is at P7 and image 2 is where his clubhead is about 6" post-impact.

Note that his clubface is still square relative to his clubhead path even though there is visual evidence that his clubshaft is flipping passed his lead arm due to a finite amount of lead hand motion in the direction of a greater degree of lead wrist extension.

What I have repeatedly noted when examining the P7 => P7.1 time period of pro golfers, who perform a flipping subtype of non-DH hand release action, is that the degree of increased lead wrist extension happening is very small (~5 degrees by P7.1) and that they still keep the clubface square relative to the clubhead path for many inches post-impact despite their small degree of lead wrist flipping motion. I now believe that small variations in the degree of lead wrist flipping between P7 => P7.1 is inconsequential, and I now believe that there is no benefit to using a DH-hand release action (compared to a flipping subtype of non-DH hand release action) when it comes to hitting the ball consistently straight. I now reject my previous theory that using a DH-hand release action (where the degree of increased lead wrist extension happening between P7 => P7.1 is smaller in amount) is beneficial in terms of a pro golfer's ability to consistently generate a straight ball flight pattern.

So, if there is no practical value to performing a no-roll subtype of DH-hand release action thorugh impact, then why do a subset of pro golfers perform that type of hand release action between P7 => P7.4? I think that there are a number of factors that can predispose a pro golfer towards performing a DH-hand release action, rather than a flipping subtype of non-DH hand release action, and I will now discuss some of those factors.

Consider the hand release action performed by Mike Malaska, a golf instructor based in Arizona, who previously played competitive golf in a few PGA tour events.

Image 1 is at P6.8, image 2 is at ~P7.3 and image 3 is at ~P7.8.

Note that when Mike Malaska's clubshaft approaches impact that his hands are ahead of his clubhead and he is likely to manifest his desired amount of forward shaft lean at impact. So, he does not flip pre-impact.

Then, note what happens in his early followthrough time period - note that he performs a puck release action through impact with a very straightened trail wrist motion. Note how fast he straightens his trail arm and trail wrist after impact and flips the clubshaft passed his lead arm, which is stalling its forward motion post-impact. Why does it happen? Mike Malaska describes how he performs a full golf swing in many of his you-tube channel's videos, and he states that he deliberately performs an active trail arm throw motion starting at ~P6 while using a reactive pivot motion. Note that his pelvis and upper torso are roughly parallel to the ball-target line at impact and that his pelvis only rotates more open after impact. That reactive pattern of pivot motion is deliberate - and Mike Malaska describes how he pulls his lead buttocks back away from the ball-target line in response to his trail arm throw motion. Note that when he performs his active trail arm throw motion that he throws his trail upper limb to a fully straight trail arm/fully straight trail wrist alignment while allowing his lead wrist to bend freely so that it does not impede the targetwards motion of his thrown clubshaft. Because Mike Malaska is very skilled at performing a trail arm throwing motion, he can keep the clubface square to his clubhead path through impact for many inches and he can routinely hit the ball straight in a consistent manner.

Mike Malaska's "armsy" golf swing action, which is combined with a relatively static pivot motion, is occasionally used by some pro golfers when they hit specialised shots eg. flop shots, bunker shots and short iron shots around the green. However, most pro golfers do not use his "armsy" golf swing technique for their full golf swing action (eg. when using a driver, fairway woods and long irons) and they use a pivot-induced TGM swinging action (lead arm swinging action) technique. In a pivot-induced TGM swinging action, the primary purpose of the pivot motion is to get the lead arm to travel very fast during the P4 => P5.5 time period so that the lead hand reaches its maximum speed by ~P5.5 and they then sequentially release PA#2 and PA#3 during the P5.5 => P7 time period. Most pro golfers start their pivot motion with a pelvic shift-rotation motion with a variable degree of torso-pelvic separation that allows them to keep their shoulders slightly closed during the P4 => P5.5 time period. They then usually reach impact with an open pelvis (eg. 45 degrees open) and a slightly open upper torso alignment (eg. 10 - 20 degrees open). They also develop a finite amount of secondary axis tilt during the later downswing as a result of their active pelvic-shift rotation maneuver +/- a finite amount of right lateral bend.

Let's consider an example.

Capture images of Scottie Scheffler's driver golf swing action.

Image 1 is at P6, image 2 is at P6.5, image 3 is at P7 and image 4 is at P7.4.

Note that he has reached the P6 position with a slightly open pelvis alignment while keeping his upper torso alignment closed. Then his pelvis continues to rotate counterclockwise to become more open by impact. Note how he acquires a slightly greater degree of secondary axis tilt and a small degree of right lateral bend by impact. His upper torso becomes slightly open at impact, but to a lesser degree compared to his pelvis. As his upper torso rotates counterclockwise between P6 => P7 his shoulders are turning in a more ferris-wheel manner that allows his trail shoulder socket to get further downplane; and he obviously gets his trail shoulder socket far enough downplane by P7 to avoid "running-out-of-trail arm", and he reaches impact with a slightly bent trail arm and a slightly bent trail wrist.

It is very likely that his lead arm reaches its maximum speed near ~P5.5 and then slows down by ~25% between P5.5 => P7. I don't have measurements for his lead hand speed at P5.5 and P7, but I suspect that the average lead hand speed for a pro golfer could be ~24 mph at P5.5 and ~20 mph at P7 in a driver golf swing action. It is not unusual for the lead hand speed to slow down between between P5.5 => P7 in a pro golfer's driver swing action thereby allowing for the successful completion of the sequential release of PA#2 => PA#3 by impact.

Note that although he has a fair amount of secondary axis tilt at impact where his head is still vertically positioned above a point on the ground that is just inside his trail foot, that his lead shoulder socket is vertically positioned above the ball position at impact where his lead arm/clubshaft are in a straight-line-aligment at impact. Also, note that his lead upper arm is still closely adducted against the pectoral area of his lead upper chest wall at impact. Between P7 => P7.4 his lead arm becomes angled more towards the target because his lead hand is still moving targetwards, but the upper half of his lead upper arm still remains closely abutted aganist his lead upper chest wall.

Here are capture images of Rory McIlroy' driver golf swing action.

Note that the descriptions that I provided with respect to the pivot motion and lead/trail arm motions of Scottie Scheffler's driver golf swing action also apply to Rory McIlroy. There are negligible differences eg. Rory McIlroy gets his trail shoulder socket slightly further downplane by P7 so that his trail elbow and trail wrist are slightly less straightened at impact.

Now, let's consider the driver swing action of Will Zalatoris, who uses a DH-hand release action through impact.

Note that he has a more assertive pelvic rotary motion during his early-mid downswing and he has an overtly open pelvic alignment at P6. Note that his upper torso has a slightly closed alignment at P6 and it obviously requires a greater degree of torso-pelvic separation to achieve this pelvis-upper torso alignment at P6.

Note how he continues to rotate his pelvis very actively between P6 - P7 and he has a very open pelvic alignment at impact.

Note that he develops more secondary axis tilt than Scottie Scheffler/Rory McIlroy by impact. He also manifests more right lateral bend that allows him to get his trail shoulder socket further downplane by impact, which allows his trail arm and trail wrist to be more bent at impact (even though his lead hand is opposite the outer border of his lead thigh at impact).

Note that his lead hand is slightly ahead of his lead thigh at P7.4 and there is a small degree of separation of his lead upper arm away from his lead upper chest area at P7.4 - suggesting that his lead arm is possibly traveling marginally faster (compared to Scottie Scheffler and Rory McIlroy). However, it could just be due to the fact that his lead shoulder socket is further back at impact relative to his ball position. Note how he can still maintain a slightly bent trail arm and a slightly bent trail wrist all the way to P7.4 even though his trail elbow is still closely aligned relative to his trail hip joint area (which is closer to the target because his pelvis is far more open at impact).

I think that the major reasons for all these biomechanical differences, which are causally responsible for his ability to perform a no-roll subtype of DH-hand release action, is due to the fact that Will Zalatoris has the athleticism and flexibility to perform a more physically-assertive pivot motion. However, there is no reason to believe that it increases his ability to successfully complete his sequential release of PA#2 => PA#3 by impact, and there is no reason to believe that he can more consistently hit the ball straighter than his fellow pro golfers who use a non-DH hand release action (like Scottie Scheffler and Rory McIlroy).

Jeffrey Mann.

https://newtongolfinstitute.proboards.com/thread/1153/comparing-dh-non-release-action