Hackmotion Extension/Flexion

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Save $50 off the Hackmotion Pro: https://hackmotion.com/rotaryswing. The Hackmotion device is the first training aid I can honestly say is worth it over a decade. It has already dramatically changed my ball striking for the better and as you learn how to use it and interpret the data, you'll likely have the experience.


One of the most important things that you're going to discover by using the HackMotion is how little the greatest ball strikers move their wrists throughout the swing.

And in this video, we're going to talk about one dimension, which is extension and flexion.

This is the one that's most common.

And for those of you who bought the HackMotion base model, that's what it shows you is extension and flexion.

If you bought the Pro model, it shows you rotation and ulnar deviation and radial deviation.

But we'll talk about that in another video.

I want to keep this one simple for those of you that have the base model.

And this is applicable whether you have the HackMotion or not.

To understand what your lead wrist and what both wrists are really doing throughout the entire swing.

And the answer is very little.

In fact, it was shocking to me how little the wrists were moving in the Tour Pro data that you look at.

Now, just to be clear, there are multiple release patterns.

There are two really common basic ones that you'll see on Tour.

This one that we're going to discuss today is the most common and what all the goats did.

But you can see in modern players like Dustin Johnson and Joaquin Neiman, who have a different release pattern.

That also comes with the HackMotion if you look at the data.

But that's not something I'm going to discuss.

That's not what the goats did at all.

So what we want to focus on today is understanding what this lead wrist does throughout the whole swing.

And really what you want to feel and understand is that once you have this initial extension set.

And so this would be neutral where my wrist is basically flat with my back of my forearm.

This would be a lot of extension and this would be a lot of flexion.

So in the swing, What we've learned from the greats and modern tour players is that they maintain this extension throughout most of the backswing in a very, very neutral way.

And what I mean by that is, they don't go to the top and try to bow this wrist like you see in Dustin Johnson.

That is a different release pattern.

And once you start trying to combine these two things is when your swing starts getting really, really wonky.

If you have a really bowed left wrist at the top and then you're trying to release the club, well, the club's already shut.

You have to release the club in a completely different way.

But what the greats did is they maintained much of that extension all the way to the top.

It could gradually flatten for sure.

Some did more than others and a lot of it depends on your grip.

But what you want to try and feel is that this extension is maintained throughout the backswing.

Just a little bit of extension, a tiny bit of cupping.

And then as you come down, you're still maintaining that, gradually flattening it.

And then right as you get down into the hitting area, we see them bow it just a tiny amount right before the release.

And then it goes back into extension.

What a lot of golfers try and do, And where they actually end up flipping is that they start trying to bow the wrist a lot because they're tired of slicing.

And so they get that club face really shut.

And then as they come down, they find that there's nowhere else for this wrist to go.

So eventually it runs out.

And even though you've bowed the wrist coming at the top, the wrist actually goes back into extension.

And you scoop and flip, even though you were trying to do something that caused the exact opposite.

Just like I always say in the golf swing, it's typically you need to do the exact opposite of what you think you need to do.

And that's generally correct.

And this is no different.

You would think in order to have a nice bowed or flat left wrist at impact, you would want to bow or flatten that thing as early as possible and just maintain it.

Can't do that unless you have a lot of body rotation like Dustin Johnson does.

But the average guy is not going to be able to move their body like that.

And the greats, they didn't do that anyway.

It's way harder on the body.

It takes way more athleticism.

The greats simply maintain that extension, bowed it just before impact, and then released it and let it go back into extension.

The feeling for this is what's really important.

The feeling is that as you're going back, you maintain that extension, you're maintaining that extension.

And then as you're coming down, once you get into that goat delivery position, that's when your wrist bows.

So when you think about it in terms of timing, this is all happening extremely fast in the swing.

But you can practice doing it slowly by going to the top, maintaining just that tiny amount of extension at the top.

And then as you come down, right as you get into that goat delivery position, you'll see that my wrist naturally wants to flatten.

I'll go to the top.

So I've still got a little bit of extension, a little bit of extension.

And it's right here that the wrist starts to bow just for a split second, and then goes back into extension almost immediately.

This is happening so fast.

But that's what's interesting about it is that it's a very dynamic movement in swings of great ball strikers.

And in the release of Tiger, as I showed in the introduction video about Oleson's swing, and you can see how the release patterns match up so well, they're not trying to get a flat wrist and maintain it.

They're maintaining the neutral, rough position or slight extension at address all the way until very late in the downswing.

And once you're in this position and the club begins to release, it's natural for the wrist to bow instead of doing this.

But again, if you're flat at the top and bowed all the way down, eventually you run out of wrist.

And then it's just going to start flipping and it's got to release and go the other way.

So practice feeling that this wrist maintains the extension all the way to the top, all the way down.

And then right as you get into the goat delivery position, Let that wrist start to flatten back out and understand that that has to then release on the other side of the ball.

Again, I've showed Bobby Jones' release quite a few times because it's an extreme example of how much he lets that wrist release.

Instead of a lot of golfers are trying to maintain this forever and ever and ever, it takes a lot of strength to do that.

And you can definitely play that way, but you'll find that you start fighting the ball going left and flying really low.

So instead of what the grates did, slight bowing and then extension almost immediately after the ball.

When you look at the data, which we're going to look at now, I want to show you what this looks like in real time.

So you can get a visual in your mind of what's really happening with the release.

And how you maintain that extension throughout the swing.

So here's the very first swing I made with the hack motion, not having any idea what to expect.

I didn't think anything about it at all.

And this orange line is showing flexion and extension.

At address, I've got 20 degrees of extension or cupping in the wrist.

And you'll see as I go from address to throughout the backswing that I naturally start to flatten that wrist out and actually start to get it slightly bowed throughout the entire swing or early in the backswing.

And then as I would go from there, it would start to bow a little bit more as I came down.

And then I would be about seven degrees, six or seven degrees bowed at impact.

What I saw that the tendency would cause as you start to flatten the wrist so much so early, this is what makes the club want to go inside.

It wants to go inside your hands, make the swing a little flat and around and deep.

And so as you'll see in the next clip, I started to change this after comparing my swing to the tour player data and saw that I had a huge improvement in my consistency by just doing less.

So after using the hack motion, you'll see that my wrist began to become much more stable throughout the backswing.

Now, I had a tendency during the backswing, as you saw from the first clip, that I would want to start to flex that wrist early.

And this would also tend to cause me to get the club to go a little bit inside.

And so I saw, studying the data, that the tour pros are keeping these hands really quiet throughout the entire backswing, which makes the club face so much more stable to control.

And then what you would see is a little drop where they would go into flexion right about GDP, which is happening right about here at this point in the swing.

And then allowing me to maintain some flexion into impact and then get into the release.

So this I went out and played golf with, and I couldn't believe how easy it was to keep the goal going in front of me.

I hit so many perfectly dead straight shots with long irons off the tee, which is a golf course I was playing.

I couldn't hit a lot of drivers.

And I just kept striping three iron after three iron with ease because my wrist felt so quiet.

And you can see the same thing.

I'll talk about in another video, the ulnar and radial deviation, staying very, very quiet throughout the whole swing.

You can see that the tour pros just barely move their wrist throughout the swing.

Let's take a look at the tour pro data a little more closely.

Now, when we look inside the app at Oleson's data with the six iron, you can see the flexion extension.

The orange dotted line is incredibly constant throughout the entire swing.

In other words, where he starts at address, he's basically maintaining that throughout the entire swing until he gets into GDP, where you can see the little decline on the impact line, where he starts to move into flexion or starts to bow that wrist just for a split second, and then it moves into the release.

And in fact, you can see both lines, the ulnar and radial deviation, the kind of teal colored line, remaining very quiet throughout the swing.

And the main thing that you see is rotation.

As I talked about in the introduction video, the rotation is where the club head speed is really released from.

If you want to be consistent, you need to move your hands relatively as little as possible, as far as your wrists go.

If you start to bow that wrist a lot or cup it a lot, you're starting to add a lot of complication into your swing.

And the hack motion shows you exactly what your wrists are doing.

And what's cool is you can actually compare your data to the tour pros.

So first things first, Try to work on maintaining that extension constant throughout the entire swing until you get to GDP.

And add a little bit of bowing as you strike the ball.

And see how that works out in creating a lot more stability and a lot more consistency in your swing.

Must be Premium Member to Comment

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Dany
At the top, the wrist start rotating back toward the target according to the graphs. At the same time, we are side bending and supinating our right arm (GOAT). Am I right saying that the shallowing of the club is coming from bending and supinating and the wrist rotation, which is going in the other way, is keeping the club head from being stuck being the hand? Thanks!
May 16, 2025
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Craig (Certified RST Instructor)
Hello Dany. Correct if I am reading correctly.
May 16, 2025
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Ross
The graph at 9:35 has me puzzled. The rotation curve for the reference graph is zero at address and zero at impact. That it what I would expect. Your rotation curve is zero at address and about +50 at impact. That is not what I would expect. Was this shot the biggest hook of all time?
April 14, 2025
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Craig (Certified RST Instructor)
Hello Ross. This is more a sample just to show you. It would be way too closed at that range.
April 14, 2025
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Scott
So maintain left wrist extension at the top? But there are many other videos where you say that at the top the left wrist loses extension as it moves slightly into a flat position, no?
July 23, 2024
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Chuck
It can and does lose some depending on how much lead arm is involved in the swing. Those who maintain more extension are more trail arm dominant, but of course, most golfers fall somewhere in between and the more lead arm dominant you are the more the wrist will want to bow.
July 23, 2024
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Jeff
Chuck, at address, using the recommended "Knuckles-down release," the only way I am able to achieve getting into the proper (+15 extension, which is at the edge of too much extension) extension is to have forward shaft lean. I calibrated the hack motion correctly (double, triple check it). I am using my normal grip, which is the same as what you show in the grip video. My setup, ball position (off the lead ear/logo of shirt) and club shaft (in line with the ball) are all IAW RST fundamentals. I have checked to make sure my lead arm is relaxed and not internally or externally rotated as was with the case of Larry in your building a full swing video. Any advice on what is causing this? I showed this to Craig (my instructor for the past year) and unfortunately, he wasn't able to help me solve the issue. Hopefully you'll ('The One") be able to provide an answer/solution to this.
April 26, 2024
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Chuck
That's an interesting one, I'd need to see it to tell for sure, but it sounds like a small setup issue like being too far onto the lead foot and the lead shoulder too far forward. If you feel you have more axis tilt and your trail shoulder hanging back more of your trail foot does that change it?
April 26, 2024
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Jeff
Can I show you my setup in a video on the community blog so you can check it out and give a shout out to you when it's posted. I'll check the things that you mentioned that might be the issue on setup. I normally use cameras and monitors for both the FO & DTL view simultaneously. Maybe the lead shoulder too far forward..??? I'll check on it and let you know. Thanks for all you do for the community Chuck and kudos to Craig. He has been an amazing instructor for me.
April 26, 2024
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Chuck
For sure, let me know when you posted it up there.
April 26, 2024
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Jeff
Hey Chuck, I posted up the video. I had to make 2 post in order to get a FO and a DTL. The videos have audio so you are able to hear the sound when I have the correct extension.
April 26, 2024
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Paul
Chuck, What are the recommended flexion/extension ranges for the Hackmotion? I'm not sure the pattern a is a good match for the Goat swing. Thanks!
April 20, 2024
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Chuck
You can use the same as Olesen's in the app
April 22, 2024
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Stefano
Hi Chuck Please, how do I get a discount on the hack motion device purchase, as a member of rotary swing? Thanks Stefano, from Italy
March 25, 2024
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Chuck
Go to https://hackmotion.com/rotaryswing and it will be automatically applied.
March 25, 2024
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Christopher
Chuck, I ordered the HackMotion Core (thanks for recommending this and getting us a discount!) and I am > 95% accurate at the top of my backswing but am averaging around 15 degrees of EXTENSION at impact. Per the graph of a flip presented in HackMotion, it does not appear that I am aggressively flipping but I am not sure. Do you have any suggestions on how to get more flexion at impact? Do I need to upgrade my HackMotion software to the Plus or Pro? Thanks again for all of your great work on this website! Chris.
March 15, 2024
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Chuck
Hi Christopher and thanks! I'm working on a video right now that covers ulnar/radial deviation as they go hand and hand with extension/flexion. But if you don't want to go for the upgrade to the Pro version to get that data, realize that the most common cause of the flip when looking at the data is trying to bow the wrist too much too early and then you run out of anywhere to go as I discuss in the video or you are cocking the wrist too much (too much radial deviation on the Hackmotion) and this cups the wrist (too much extension) and makes it hard to get rid of the extension in time before impact.
March 15, 2024
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David
Chuck, the HackMotion videos are fascinating and a wonderful insight into understanding wrist angles during the swing. This might not be the best place for my question, though it is related. I joined RotarySwing to learn a swing that requires less swing thoughts and I am delighted with my progress so far. Tell me, why don't you address the ball with the strike wrist flexion then maintain that angle throughout the whole swing? That would reduce swing thoughts, I think.
March 13, 2024
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Chuck
The golf swing is too dynamic. As much as it logically makes sense to take this approach, there's a reason you almost never see a good player doing it. You must give the body areas to move THROUGH the swing. Just trying to hold it static doesn't work as it restricts movement too much and in this case, actually most often leads to the exact opposite desired result - a flip.
March 14, 2024
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Dushi
Chuck, I have to admit that my head is spinning. The GOAT Code and GOAT Theory videos have been eye-opening and exciting. My swing feels more free and athletic than ever. I have swing feels instead of swing thoughts and it’s been fun to be a part of your deep dive into what the GOATS really did in your swing. But I find myself on the range not knowing what feel should I work on. The side arm throw with a weight shift? The wide-glide-wide drill emulating Tiger circa 2000? Or trying to get into the GDP and working on getting my wrists to copy Thorbjorn Olesen? Or do I have to do all of these things to swing it my best? Is there a hierarchy to all of this? Is there a framework in which to categorize all of this new GOAT info? I’m still topping out at 105mph with my driver so I think I have to be missing some pieces.
March 12, 2024
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Chuck
Focus on the main core videos until you have the basic motion down, then simply use GDP as a checkpoint and the refining videos to dial things in. If you can hit the ball well with wide glide wide then you are well on your way.
March 14, 2024
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Dushi
Thanks for the reply Chuck. Swing is feeling good as I quiet the body and “throw from the top”. Contact has been great and I’m picking up speed for sure. Club Path has zeroed nicely, but club face can be a little open, a little shut or square. So misses are right and left. I’m trying to bow the left wrist as I throw from the top while moving the hands fast. Any tips on how to keep the face more stable in the downswing and through impact?
March 16, 2024
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Chuck
You may be getting too much deviation (wrist cock) which opens the face and then you are struggling to square it back up. Could also be too much rotation, but I would start with deviation.
March 17, 2024
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Dushi
Thanks Chuck. Radial deviation correct?
March 17, 2024
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Chuck
Yes, exactly
March 18, 2024
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Chris
Hey Chuck , Are you still thinking the club is ‘thrown’ from the top with this new wrist data ?
March 10, 2024
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Chuck
Yes, you can see that in the data in Olesen's swing. I've had this asked a few times so I will probably do a video on it soon
March 10, 2024
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Neil
Chuck, it's great to see these videos with HackMotion. I've been using HackMotion for about a year, working with Craig on changing my swing. I agree with you, absolutely the best training aid I have ever used. One questions regarding when to bow. When I'm doing a Lead Arm Parallel drill, the time from the top of my backswing to GDP is 0.23 seconds and the time from GDP to impact is 0.07 seconds and this is with a shot that only goes 100 yards or so. When do you "think" about starting to bow? Is there a trigger point in your swing when you do it or is it, as you say in the video, only by drilling more slowly? Thanks, Neil. BTW, whatever you pay Craig, it isn't enough, he is fantastic!
March 9, 2024
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Chuck
Hi Neil, great question. As you can imagine, it's impossible to "think" the timing of this as it happens much too fast. But, if you move into GDP, the wrist will naturally start to bow. When it starts to flip is when we aren't moving through GDP correctly. The momentum and weight of the clubhead when the trail arm is in GDP leaves little choice but for it to bow naturally.
March 9, 2024
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Rick
Thanks Chuck, this is exactly what I needed to see! Got my Hackmotion sensor (thanks for discount!) on Monday and was practicing with it. My initial thought was that I needed to bow my wrist at the top of the backswing, and exactly like you say, it was showing me flipping at impact. Now I know better. BTW, for rest of members you can start with the base Core model at $280 and then choose later to upgrade to Plus or Pro, which is a software update you pay for. The hardware is exactly the same for all 3 versions. Thanks again!
March 6, 2024
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Chuck
It's an amazing device once you know what to do with the info, total game changer!
March 7, 2024
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David
Chuck, thank you for the simple explanation of a very difficult process. I can't wait to calm the wrists and hands and post some great results. This is absolutely AWESOME content! This is simply another Homerun in the GOAT series! Keep it coming! This information is finally giving us the simplification of what needs to be done to be a great ball striker. AMAZING STUFF! Keep pouring it on. Thanks again. You're Da Man or should I say Da Decoder of the Golf Swing! Unbelievable!
March 6, 2024
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Chuck
hahaha, thanks David, I'll keep chipping away at the mysteries of the swing for us all!
March 7, 2024

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