How Knee Flex Determines Swing Plane

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Do you struggle with swinging too far from the inside? Part of the problem could actually be your knee flex.


One of the most common set up mistakes I see people make every single day. Both in person lessons and online, is having too much knee flex. And a lot of it comes from not understanding, when we're talking about setting up your weight through your ankles. That just by doing that, you don't need to then squat down. Because watch what happens to my upper body, my spine angle, as I start to add too much knee flex. 
So, let's just say, I'm going through my set up routine. Hinging forward and then adding a little bit of knee flex, very little knee flex. As I start to add too much, notice that my spine angle begins to change. And that's what happens all the time as golfers start to try to get set up and feel really stable and balanced over their ankles, they add too much knee flex. And now, all of the sudden their spine is setting themselves up in position where they have to swing very shallow and into out.
So especially, if you struggle with hooks or blocks are coming too far from the inside, hitting it off the hozzle, hitting it too close to the heel. The first thing you need to check is your knee flex. The more you flex, the more upright your spine is going to be. And as you know, I've talked about it ton. Your spine angle is one of the primary dictators of swing plane. So, you need to make sure that your upper body is tilted forward, your buttons are your shirt are pointing down at the ground. And then just relax your knees slightly, and your weight is still over your ankles. But, you don't have all this added knee flex that puts you in position where you have to swing into out.
So, let's take a look. I'll hit a couple here and I'll show you, just little nine to three swings. And I'm going to stand with a lot of knee flex. And I'm going to show you what happened. Notice how my hands get lowered. This is perfect for a bunker shot, but not great for a full swing. Now that my spine is pretty upright, as I go back, the tendency is going to be for me to swing way into out. And launch the ball to the right. 
To fix the swing plane, we have to first set our spine angle correctly in the first place. Which means feeling much more hinged forward, than I ever see most amateur golfers. Almost everybody tends to set up like this. You've got to get comfortable being bent forward more, your hips back more. And then your weight is over your ankles with relatively very little knee flex. And now my spine angle is set in a position where my swing plane can come down more on top of the ball. And drive the ball down the line. Instead of out to the right.
So, when you're adding knee flex, the trick is as you're hinging forward and going through your set up routine, that I talk about in the set up videos. Just barely relax the knees. Try to stay relatively tall through your lower body and hinge more from your hip sockets. So that your belt line angles down. That's going to allow my spine to stay in neutral and allow me to create a much better swing plane. Then if I'm standing up very upright with a lot of knee flex.

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donn
My set up had my knees slightly flexed - but in my review this video was recommended. I have played around with this and I am not sure if my "feel" is real or not - can you tell me... This is what I found when I set up and used a slight knee flex I believe my hip socket is somewhere over my heel. When I slowly make a back turn and my hands get up around the toe line, if my body does not compensate, I will fall over backwards -- If however, I add a certain amount of forward lean to my shin bones and a little more knee flex, then I believe my hip socket is lined up more over my instep or front of ankle and i seem to have much better balance. Can you elaborate on this for me?
November 7, 2020
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Craig (Certified RST Instructor)
Hello Donn. The line you are looking for is from the ankle joint/back of the knee/hip socket. Sounds like the touch more forward lean is getting you better weight placement instead of too far towards the back of the heels.
November 9, 2020
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sjahari
i find it difficult to have slight knee flex. More comfortable with more flex. But if I put more weight back on my ankles and heels then it is easier. But I am worried that there is a problem with my weight being too far back? If I put weight in the middl;e of the foot then I want to use more knee flex because it seems easier on the muscles of my legs. dont know if you understand what that means. Trying to get this right for bootcamp
June 18, 2020
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Michael (Certified RST Instructor)
Hi Sjahari It sounds like you are not hinging enough from the hips. Take a look at the "5 Minutes to the Perfect Golf Setup" video and make sure you hinge forward until you toes lift up and the relax your knees.
June 19, 2020
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sjahari
thanks. That does work. But it feels like too much hinge now. Gotta get used to this. But it makes it much easier to have slight knee flex. Maybe you guys could look at my knee flex and hinge in the next video I send in?
June 19, 2020
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Michael (Certified RST Instructor)
Hi Sjahari Yes that's no problem. Just mention it in the comments to your submitted review.
June 19, 2020
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Kevin
I had a good learning today - noticed I was standing too far away from the ball and had too much knee flex (see picture). After adjusting those two things it drastically improved my arm position at the top of the backswing and allowed my hand path to work straight down easier from the top. Amazing how important setup is!
May 15, 2020
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Craig (Certified RST Instructor)
Hello Kevin. Setup is of the utmost importance. Great catch.
May 16, 2020
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Eric
This video was recommended in my swing review. I found that I bend my knees a lot as a way to shallow my downswing and swing from the inside. With my bent knees I hardly ever come over the top. Reducing knee bend led to more pulled shots by a factor of 10. Do we solve this plane/path problem somewhere else down the line?
March 28, 2020
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Craig (Certified RST Instructor)
Hello Eric. Take a look at How to Fix Plane and Path Video. It sounds like you are adding a compensation at address to fix the fault vs proper setup and curing why you come down on the ball steeply.
March 28, 2020
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Louise
I have the proper knee flex at address and correct swing plane (according to TrackMan) but I tend to bend my knees too much in the downswing. How can I prevent the excessive knee bend?
February 9, 2020
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Louise
Yes, I tend to squat on the downswing but not sure what you mean by not exiting.
February 10, 2020
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Craig (Certified RST Instructor)
Hello Louise. Do you tend to have excessive squat and not be able to exit the position?
February 9, 2020
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Kevin
Hi Craig - I’ve been working on my setup and the mirror and also have found that when I have too much knee flex I tend to over rotate my hips in the backswing. It’s easier for me to maintain “laser beam knees” with less knee flex. Just wanted to confirm that makes sense? It probably has something to do with where my weight pressure is in my glutes and hamstrings vs quads
February 2, 2020
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Craig (Certified RST Instructor)
Hello Kevin. The more flexion you have the less of a chance to over rotate. However, I do see a lot of players setup with excessive knee flex and leave that position to over rotate because it is uncomfortable. It is much easier to load and stay in control without the initial excessive knee flexion. Your post makes since to me.
February 3, 2020
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Michelle
I know it may be trivial but its hard to concentrate on the video with such beautiful scenery. Although I would hate to have to go collect the balls in that long rough. LOL. Cheers Michelle
December 26, 2018
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Craig (Certified RST Instructor)
Hello Michelle. Appreciate the compliments on the back drop. Getting the balls picked up on the side of the cliff is a really good workout.
December 27, 2018
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James
Thanks to Craig for my two recent reviews... I know my second one was somewhat close to the first, but it really was a good thing to do. It emphasized the targets of practice for me.... Craig's "yell" was really something I could get next to...reminded me of a time long ago in the Army! Made an excellent "impression" with a bent to self discipline! Good job! That and thanks for a very good plan for progress. The second review was a great "check point".... See you after a bunch of work in the basement. Philly Phatz
November 10, 2018
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Craig (Certified RST Instructor)
Hello Jimmy. No problem. Glad you enjoyed the reviews. Only want you to succeed! Sometimes on the lesson tee players do call me a Drill Sergeant. But, in the end they love me for it.
November 10, 2018
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Anthony
Craig. Thanks for my recent review. Clearly my knee flex was incorrect. I have now watched this video to determine correct knee flex. Can you tell me how the knee flex might differ for chip and short pitch shots or should it be essentially the same as full shots?
October 10, 2018
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Craig (Certified RST Instructor)
Hello Anthony. Knee flex is going to stay relatively the same throughout. The only big difference will be in the bunker when you start to lower the hands "your butt" needs to be lower.
October 10, 2018
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Brian
Wow. I'm a 12 handicap at a challenging course and I am realizing through the videos so far that nothing I'm doing in my swing is correct. And I believe that is accurate. I am the classic over bent knees-straight back-push swinger. The bend at the hips video was an eye opener. I went out in my yard and just bent correctly and took less than a half swing hitting down on the top of the ball and the ball shot out like a rocket and went across the street. i really appreciate the teaching aspect of these videos.
July 17, 2018
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Craig (Certified RST Instructor)
Hello Brian. Great. Thanks for the post and compliments. Looking forward to continued progress on your swing!
July 17, 2018
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Eric
Interesting, I was told that I have too much knee flex. But it causes my hips to over rotate and and my backswing goes too far back so I have to start down with my right shoulder and arm to start the swing,even if I concentrate on starting down with the lower body and left foot, ankle, etc.
May 14, 2018
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Craig (Certified RST Instructor)
Hello Eric. Knee flexion will tend too restrict hip turn. However, if you start with a lot and gradually lose it. Easy way to over rotate.
May 15, 2018
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Diane
Hi Chuck This explains a lot. I have massively improved my setup following all your instruction, but extra piece also helps to get a smoother core rotation, I just wasn't hinging forwards enough. Definitely a point to add to my practise!
May 12, 2018
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Craig (Certified RST Instructor)
Hello Diane. Fantastic. Happy to hear the new video lesson helped.
May 12, 2018
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richard
thanks for this video, very clear explanation and has helped me greatly however, does this set up stay the same for uphill and downhill stances?? Richard
May 11, 2018
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Craig (Certified RST Instructor)
Hello Richard. Glad you liked the video. Take a look at the Specialty Shots Section. You will have to make some adjustments according to the slope. For example: ball below you may need a little more increase in knee flexion.
May 11, 2018
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Marcel
Is is the same with the driver?
May 10, 2018
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Craig (Certified RST Instructor)
Hello Marcel. Yes.
May 11, 2018
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Peter
Wow. Where are you Chuck?
May 10, 2018
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Chuck
Telluride, CO
May 10, 2018
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Peter
Thought so! Awesome. Enjoy it!
May 10, 2018

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