I had a video out a few years back that focused on the Kinetic Chain, which is the connection of body parts one uses to produce leverage in the golf swing.
The reason that Modern Golf Swing models are all faulty and mechanically unsound because they break the chain when they involve restricting the hip turn and twisting the lower body against the restricted lower body to achieve the shoulder turn.
Very simply, if you can remember the lyrics from the Skeleton Dance Song:
… then you know basic anatomy and that everything is connected.
This is why you have to allow the leading foot to lift on the back pivot – the shoulders turn with the hips powering the swing, and the leading knee has to “swing the gate” freely to do so.
When you swing a golf club with the full-body swing of the Classic Golf Swing (it wasn’t just Hogan – every swing in that model is a full-body swing or something is wrong), you swing with the entire body connected, which of course is what you want.
You can actually see in a swing that uses pure leverage, what I call the “Leverage Arc,” which is sort of a backwards-C arc in the leading body edge of a swinger when filmed from a diagonal view.
I noticed it when looking at the more leveraged swingers a while back and this is actually the first time I’ll be talking about it – something new for the WAX crew!
I first noticed it looking at young Jack Nicklaus swing:
When you watch Jack’s left leg “swing the gate” on the back pivot until his knee stops moving inside, that leg moves back on the down swing, the foot plants, and the leverage is unbroken from the leading shoulder all the way down to that leading foot:
When you look at Mike Dunaway from the front diagonal, you will see the same thing as he shifts that leading leg back to the target, plants the leg and exerts his full-body leverage:
Again, leverage from the ground up, and this is the real “using the ground,” because if your leading foot is leaving the ground at impact, how are you using the ground?
Using the ground means you’re placing all of your energy into that leading foot so that you can pull your leading shoulder up and away.
When I was able to produce 160 mph ball speed with a Momentus Heavy Driver (average Tour ball speed with a regular driver at the time was around 166 mph), I was using my entire body to leverage that club:
Again, you have the planting of the leading foot with the return of the leading knee, which pulls the hips around, pulling the leading shoulder along.
You can see it without even having the lines drawn with the Hogan swing, which is frozen right in mid-arc:
And that is also the reason for the release of the trailing foot post-impact the to finish.
The one problem that Classic Golf Swinger would have had was the risk of hurting the back on the finish with that Reverse-C position, but this Reverse-C finish only occurred when the swinger did everything correctly except release the trailing foot.
Even though Nicklaus never released that trailing foot:
… he still never injured himself because the risk is so low, albeit still there.
Contrast this with Tiger Woods’ post-impact action, which is beautifully isolated by this clip manipulation showing something that is supposedly happening (apparently, showing us that TW has a left leg):
Notice how little leveraging action Tiger actually has into the ball – as soon as he’s post impact, it’s all arm action to finish as he chases the ball with his upper body:
Right when that reverse arc should be appearing, Tiger comes up and out of the position with that upper body chase that they’re all doing.
Now, I’ve said a million times that nothing you do after impact has any effect upon the ball, but what happens before impact will affect what happens after impact, motion-wise, and you can see that TW has absolutely no leveraging kinetic chain action through the ball.
It’s a squat, snap and swipe.
And that’s why Tiger keeps needing back surgery. He has no natural leverage remaining in his swing, so he just keeps trying to add more muscle in order try to brute-force that club through impact.
The stronger he gets, the more damage he does to his back.
WAX Golf 
This was a great analysis and explanation of leverage and using the ground in the true sense.
I feel Tom Watson’s modified swing that he “discovered” was perfect.https://www.youtube.com/watch?v=piHHfKxNP9w
He wouldn’t have had to change anything if he’d released his trailing foot, the failure to perform such action being the cause of his Reverse-C finish.
As Watson got older, it would have become a problem. But with his new swing, it is visibly lacking the leverage he had in his younger years.
My opinion.
Recently, my ball striking seemed to have vanished and with nio discernable pattern- fats, thins, left rigth and topping off of the tee! It was twilight zone golf for me leading to scores I havent seen in 20 years!! So, I wne tinto thearchives and found my copy of the Kinetic Swing video and discovered that exogenous YouTube golf guru influences had skewed my posture at address into an unintelligble mess. a review of the video put me back into shape and posture.The results: Solid ball striking once again with vestiges of command on shot shape emerging out of the wreckage. Stay connected in sound posture and good triumphs over YouTube golf!
Viewing clips online and having them stuck on your mind when on the course,is a very common problem in the modern world. My personal bane is having Payne Stewart in mind and trying to swing as fluidly as him.
Nearly nothing good comes of watching golf swings on YouTube unless it’s one of the classic greats.
DJ, Looks like you have to shoot more video for your new E=MCS series (LOL). Last week I started to incorporate some of your ideas with my thought of getting the right hip to turn as far to the left and behind me as possible while still keeping my head over my right knee. This leads to the left knee getting very close to the right knee. I don’t own it yet but my ball striking is very much improved and my distance is at least 10 yards further with my irons. On the downswing, thhe head must stay on or behind the line from top of the head and through the middle of the left ankle. This leads to the C position. Keep up the brilliant work!
Bob, it looks like you’re getting there! Well done.
Funny thing you mention the video – I was just thinking today that I really want to get a video out to people and I don’t want to wait until I am back in swing-shape (I did something to my left shoulder during the winter and haven’t swung a club in months because of it).
I have swing clips from my swing archive that are just about what I would be doing now, and I could likely have a video ready in not too long. No one ever swings exactly like another person so a little variation here or there on my part in swing clips wouldn’t make a difference to anyone watching the tutorial and following along.
Barring that, I have also been contemplating having a membership section here on the site where people wouldn’t have to actually purchase and download a video – the material would be posted therein to access 24/7, with swing clips and all associated instruction – that could be set up in days.
Perhaps a survey would be in order?
Hey DJ,
How should I think of the right knee flexion in the backswing? Should it remain the same flex
as setup? Should it straighten a little but still
maintain some flex? Or, should I allow it to fully straighten?
Another question pertaining to the pivot is what’s restricting the hip turn in the Modern X-Factor Swing? Is it from keeping the left foot glued to the ground during the backswing or keeping the right knee flexed?
To answer the last question, Scott – both!
As to your query on the pivot, it would take more than a comment or blog post to answer that. For now, the knee doesn’t have to straighten completely – nature hates straight angles.
I should get something going quickly – trying to decide whether it’s a video or opening a membership section here for people wanting to learn an MCS Golf Swing!
Well I would for sure sign up!
I’m on it, Scott. I’ll have something to announce, hopefully in the next week. 👍🏼
On the topic of Jack Nicklaus and leverage I found this great video a while ago where Jack Nicklaus actually discusses his leverage.URL was copied at the exact time https://youtu.be/UCGT06C2b6g?t=966 Footage also features Payne Stewart,and the Mighty Mike Dunaway ! God,how I’d love to of been there with those legends in the same place!