Right and Wrong - Weight Shift in S&T

[iacas]

For at least a little while I've had a theory, in fact a "belief," that there's still a weight shift to the right in an S&T; swing. My reasoning was that your chest is in front of your spine, your arms are in front of your spine, your belly, etc.

So to test this I got two scales and Dave, James, and myself set up on them. We got into a setup which we were happy to see was between about 55L/45R and 50/50 for all of us. We made a backswing and stopped at the top. The two who weren't making the swing checked the scales (which measure weight, and not what the guy swinging would perceive as "pressure" - I'll get to this later).

Turns out that at P4 the weight was anywhere from 55L/45R to 45L/55R. Very little movement was necessary to tip the scales the other way - from the weight staying forward to the weight actually moving a little backwards.

I had guessed that a stock weight shift with a "perfect" backswing might get to 45L/55R, and while that's still "plausible" using the Mythbusters method of rating things, in reality the range of motion required was so small that while static weight does get to 45L/55R, determining WHEN it gets there becomes a matter of precisely defining the "top of the backswing." If it's when the club changes direction in a dynamic player, the hips may have already started going forward and you can get numbers from 45L/55R to 55L/45R. And these differences are very difficult to see on a camera.

So before I follow up on the "pressure" comment from above, a quick comment... There's still a weight shift in S&T.; If you get 90% of your weight on your front foot just after impact or at impact, the only way for there not to be a weight shift would require you to have 90% of your weight forward at the top of your backswing. Any amount smaller than that is, by definition, a weight shift. Weight is still moving to the front foot throughout the downswing, even if you really had some goofy backswing we wouldn't teach you that put 80% of your weight on the left side at the top. In reality, the weight shift is from roughly 45-55% left to 90% left (95% or so farther into the follow-through) depending on when you define the top of the backswing (P4).

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Now, to the idea of pressure. The simple fact of the matter is that when you're not moving, pressure into the ground is the same as weight. If you bend your knees quickly you decrease pressure as your body drops, and if you jump, you apply more pressure to the ground than you weigh (that's how you get off the ground - you're overcoming your weight - gravity - with your muscles).

Also, this: stand up straight. Sense how much "pressure" your leg muscles feel. Simply put you can stand relatively upright for hours and hours and hours. Now bend your knees about 45 degrees - how much pressure do you feel now? You've not gained weight, but you feel a lot more tension in your muscles.

In reality, the pressure - through the soles of your feet - is the same in both instances, but I think people overdo the "weight shift right" because if your right knee decreases its flex/straightens even a little (and if your hips turn, your right knee is virtually guaranteed to decrease its flex), it will feel less tension. Your body will tell you there's less pressure there even though there's more, so you'll shift even more weight over there to really feel the "tension" which you feel as pressure.

If you ask people making a centered shoulder turn how much pressure they feel in their left leg and foot, they'll often say it feels like 80% of their weight is there. It's not - but because of the differences in how the legs are flexed, it might feel like that to them. Our bodies are not great (some are better than others!) at feeling "pressure" in the soles of our feet - we'll often mix in muscle tension and stretching and things like that.

P.S. When our legs are straight the muscles don't work as hard because the bones support most of the weight. When our legs are flexed, our muscles do virtually all of the work.

[saevel25]

Very interesting.. I never really concerned myself with that stuff. A cool thing is Wii fit, they got a balance test, were you try to get the bars to stop in the scales, one might be 70% left leg, 30% right, with an error or +/- 5%, then it gets really tought at maybe 50/50, but +/- 1%, you got to hold those positions for 3-5 seconds i believe. Well its fun because you realize how much you do have to put your weight on the left leg if you keep it bent. Its also a great tool to sense weight shift.

[ControlJunkie]

I'm going back to re-read the entire post, but when you talked about getting two scales, I immediately thought this might be something cool to add to the new place - http://www.golfdigest.com/golf-equipment/blogs/newstuff/2011/04/new-training-aid-can-help-perf.html

Had to post before I forgot

[iacas]

Originally Posted by ControlJunkie

I'm going back to re-read the entire post, but when you talked about getting two scales, I immediately thought this might be something cool to add to the new place - http://www.golfdigest.com/golf-equipment/blogs/newstuff/2011/04/new-training-aid-can-help-perf.html

Had to post before I forgot

We checked out an earlier version of that when we visited aboutGolf in 2010.

IIRC, Dave's weight went slightly right but was moving forward by P4 and never got really far right at all - it was a subtle shift that ended around P3 or so. Again, IIRC.

[JetFan1983]

Originally Posted by iacas

If you ask people making a centered shoulder turn how much pressure they feel in their left leg and foot, they'll often say it feels like 80% of their weight is there. It's not - but because of the differences in how the legs are flexed, it might feel like that to them.

Great point. Makes a whole lot of sense to me.

[BallStriker]

Originally Posted by JetFan1983

Great point. Makes a whole lot of sense to me.

Funny....I read Eric's full post before seeing this and thought the exact same thing.

[iacas]

Here's a guy who hates hates hates S&T.; He rails on it in other forums and goes on and on. I got this video of him (these are two different swings where his weight is as far back (right) as it can go) in the same post in which he says he "puts 75-80% of his weight on his right side at the top."

Camera angle's not perfect (it's back a little bit, not quite purely face on) but here you go:

Red border around an image so you can see this is his text below, not mine:

His rationale? His left heel comes off the ground. How much weight does he shift? Barely any. He stays pretty centered. He later says his left foot is "weightless" at a moment in time. That's like saying you're weightless when you've jumped in the air. No you're not - you're in motion and not only are you going to measure MORE on a scale when you land, but your actual "weight" doesn't change just because you've temporarily applied a force to counter it.

What can we learn from that? Feel isn't real, again. I can "lift" my left heel off the ground with 90% of my weight on my left foot. It's particularly easy to do this in a split second in video. To truly measure "weight" we'd need a static shot, and as you can see, even though his left heel is off the ground, he's NOT 75-80% right. Not even close.

[iacas]

FWIW, we did some work with SwingCatalyst towards the end of 2011 that continued to firm up the research we did on this nearly a year ago. We met the SwingCatalyst folks (and Andrew Rice) at the PGA show, and it further confirmed the things we thought to be true and that our research was leading us to believe was true. We hope to include some of the SwingCatalyst data (confirmed by SAM Balance Lab) in the 5SK DVD but it may make it into the supplemental information.

A lot of the information parallels what is said above. I'll share this little tidbit: it's virtually impossible to get your weight more close to 60% "forward" at A4 without making some rather large movements (too large, generally speaking) with the hips or head. You can subtly shift the hips back and forth to get 55/45 or 45/55 (while keeping a Steady Head, Key #1), but more than that becomes "difficult." Key #2, Weight Forward, at impact also parallels everything our research has led us to believe (with some added detail).

Also, we have further evidence and examples that weight and pressure are not the same in the golf swing, particularly at A4 (that's how I found this thread again just now - a search for "weight vs. pressure" reminded me of this, as Dave is going to San Diego to edit the DVD and I'm doing some clean-up work on the instructor training manual).

[Zeph]

I have no objections here, good stuff as usual. The "weight vs pressure" debate is interesting and I totally agree. What we percieve as pressure is tension in the muscles, which is not the same as weight. The scale test pretty much confirms the theory. If mass is not moving sideways, you can not add weight to the back foot. The subtle weight shift is more a result of the arms and clubmoving back. It's the usual "feel is not real" in golf. We don't use the technical equipment all the time as a training aid. We use them to understand and explain the golf swing and what really happens, not what professional golfers and instructors feel happens. I believe the upcoming S&T; DVD will also touch on this topic.

[iacas]

Originally Posted by Zeph

I believe the upcoming S&T; DVD will also touch on this topic.

Yeah, and I'm a bit worried for some of the numbers they show. We tried out the GASP systems balance plates and the results were way, way different than anything else we saw. And I don't just mean in the various parts of the swing, dynamically - Dave held his finish with his toes barely touching (very little pressure - shoe wasn't creased or anything) and it was registering over 30% pressure or weight.

You cannot measure weight dynamically, only pressure(s).

Dave on the SwingCatalyst at A4. Weight 50/50, pressures not 50/50, as I've said all along.

[Harmonious]

Originally Posted by iacas

Dave on the SwingCatalyst at A4. Weight 50/50, pressures not 50/50, as I've said all along.

What were the pressures at the top of the backswing during an actual swing? (You knew I was going to ask . I talked to the SwingCatalyst people at the show as well).

[Open-Faced Club Sandwedge]

Let's not forget acceleration in this equation.  At the top of the backswing, you've momentarily stopped moving, but you are accelerating.  You're going from moving one direction to moving the opposite direction, which, even during the instant you spend at rest, is acceleration.  F = ma, your mass isn't changing, and therefore acceleration = force, and the force in the golfswing is all connected to your feet pushing on the ground.

Further, let's remember how much you're accelerating; you're starting a downswing movement which is going to see your whole body moving in the direction of the target, your club moving in the direction of the target at 100 mph or more, and the ball moving in the direction of the target at ridiculous speed.  That's a lot of force, and it's initiated largely by your right foot pushing off the ground.  So right at the top, when you're starting all this, even if you haven't swayed a single millimeter backwards, you're going to be putting a lot of pressure on that back foot, and it won't just be a proprioceptive illusion.

The big takeaway here, IMO, is we should forget about weight shift and focus on movement.  Don't move (sway) onto your right foot.  Better golfers generally stay left, and there are very good reasons for it.  Weight is a force, and bringing force into it makes it very complicated.

-Andrew

[iacas]

Originally Posted by Harmonious

What were the pressures at the top of the backswing during an actual swing? (You knew I was going to ask. I talked to the SwingCatalyst people at the show as well).

I'm not going to say. We're saving some of that information for our DVDs.

But if the right knee and hip are straightening (decreasing flex) and the left knee and hip are gaining flex to allow the shoulders and hips to rotate in circles, what's your guess?

Pressure isn't weight in a dynamic system. It's an important distinction.

Originally Posted by Open-Faced Club Sandwedge

Further, let's remember how much you're accelerating; you're starting a downswing movement which is going to see your whole body moving in the direction of the target, your club moving in the direction of the target at 100 mph or more, and the ball moving in the direction of the target at ridiculous speed.  That's a lot of force, and it's initiated largely by your right foot pushing off the ground.  So right at the top, when you're starting all this, even if you haven't swayed a single millimeter backwards, you're going to be putting a lot of pressure on that back foot, and it won't just be a proprioceptive illusion.

It might be a little less force than you think. But yes, the force (pressure) right (for a righty) will generally peak slightly after A4 (but before A5).

Originally Posted by Open-Faced Club Sandwedge

The big takeaway here, IMO, is we should forget about weight shift and focus on movement.  Don't move (sway) onto your right foot.  Better golfers generally stay left, and there are very good reasons for it.  Weight is a force, and bringing force into it makes it very complicated.

Yeah, if a PGA Tour player moves his head on average 1 inch on the backswing, then he's not moving a lot of weight around unless his hips are sliding around like crazy during the backswing.

Pressure isn't weight.: http://thesandtrap.com/t/48111/jack-nicklaus-on-a-centered-pivot/54#post_621950