Weight Forward - Using SwingCatalyst and SAM Balance Lab to Explain Pressure Throughout the Swing

[saevel25]

Originally Posted by Beachcomber

Yeah, why do you have to go and describe my swing like that?  Seriously though, after hitting balls today I was thinking about this thread and noticed almost exactly what you are describing in my own weight transfer.  Maybe this is why I often hit longer clubs from off the deck a pinch fat? I dunno... But it is WIP.

I know right, i've done that for years. had the reverse weight shift, but played that way for so long that i was able to stay in balance and make myself get into a good finished position to watch the ball look really horrible flying through the air :p

[Phil McGleno]

Do you think this could explain why some pga tour players feel they load into their right side even though they might only move their heads two inches off the golf ball?

[Gaber]

Thanks Erik & Dave for sharing this - this gave me a different look on how to describe weight and pressure - Always concerned with weight transfer but in reality its pressure during my swing that needs to be noted more so in the dynamic sense!

[iacas]

To be clear:

Position	Weight	Pressure
A1	63L/37T	63L/37T
A4	47L/53T	35L/65T
A7	? *	91L/9T

* Grant posed at A4 and was 53 trail (T = trail, L = lead), but we didn't pose an impact position because I don't know that we could get very accurate. Posing at A4 is reasonably accurate because you can just make a backswing and stop when you'd naturally stop in the transition. There's a natural stopping point at A4 that does not exist at A7.

We know the "weight" is forward at A7 as well, though. We just don't have a precise number (nor would I necessarily call a posed A7 precise either - we can often pose a better A7 than we actually achieve ).

[Mr. Desmond]

Thanks again for this thread - a revelation.

I used the data to attempt to mimic the  pressure that Grant displayed - and when I was patient ...

Holy Moly .... it works.

It had to smash down on the left toes to get the left leg past the ankle, and then slide the hips, and "do the Mike thing" - separation with the arms ...

Yeah, a lot to think about...

(I also viewed another Dave Video this morning about staying centered - For me - "turn and stand up while tilting left" was another revelation. I think it was the "stand up" that did it. Erik says to feel like you're stretching out the right side and I'd used it. But "turn, stand up, and tilt" really hit home for me.")

Thanks, everyone!

[Phil McGleno]

So what youre telling us is that this is not accurate? [quote name="iacas" url="/t/64993/weight-forward-using-swingcatalyst-and-sam-balance-lab-to-explain-pressure-throughout-the-swing/36#post_813004"]To be clear:

[TR] [/TR] [TR] [TD]A1[/TD] [TD]63L/37T[/TD] [TD]63L/37T[/TD] [/TR] [TR] [TD]A4[/TD] [TD]47L/53T[/TD] [TD] 35L/65T [/TD] [/TR] [TR] [TD]A7[/TD] [TD]? *[/TD] [TD] 91L/9T [/TD] [/TR]

Position	Weight	Pressure

* Grant posed at A4 and was 53 trail (T = trail, L = lead), but we didn't pose an impact position because I don't know that we could get very accurate. Posing at A4 is reasonably accurate because you can just make a backswing and stop when you'd naturally stop in the transition. There's a natural stopping point at A4 that does not exist at A7. We know the "weight" is forward at A7 as well, though. We just don't have a precise number (nor would I necessarily call a posed A7 precise either - we can often pose a better A7 than we actually achieve ;-) ). [/quote]

[cbrian]

IMO, the pressure data is accurate, but it doesn't correspond to the picture presented.

[Phil McGleno]

Id probably agree. When do you think that is just after P6-A6 or so? [quote name="cbrian" url="/t/64993/weight-forward-using-swingcatalyst-and-sam-balance-lab-to-explain-pressure-throughout-the-swing/36#post_813383"]IMO, the pressure data is accurate, but it doesn't correspond to the picture presented.  [/quote]

[JetFan1983]

Originally Posted by Phil McGleno

Id probably agree. When do you think that is just after P6-A6 or so?

Quote:

Originally Posted by cbrian

IMO, the pressure data is accurate, but it doesn't correspond to the picture presented.

Pressure 67% forward? A4.9?

Just guessing.

[cbrian]

Originally Posted by Phil McGleno

Id probably agree. When do you think that is just after P6-A6 or so?

Player dependent obviously, but Grant is basically there at 5 or a touch later. As consistent as he is, I doubt you'd see it change much from that.

[iacas]

Originally Posted by cbrian

Player dependent obviously, but Grant is basically there at 5 or a touch later. As consistent as he is, I doubt you'd see it change much from that.

Yeah, A5.15 or so. 65% here, 70% at the next frame.

The S&T; DVDs clearly weren't synced. They're showing numbers at A5 or A6 or so for a lot of their players. The SAM (and the SC) both measure things virtually the same. The SC will guess at placing the three triangles. The SAM doesn't even guess, so even something as simple as how much you wiggle your feet at address and/or how long after you start recording and the player actually swings will change how far off the sync is.

Now, I don't think they did that on purpose (messed up the sync), but I think they didn't know how what they were using worked... Sync is important, or else you get shots like the two pictures we showed at the end of the video.

[cbrian]

And to further what Erik said, if you go back and look at the same DVD that Phil pulled that picture (66% left) from, there is another picture of Grant with his pressure being around 65% right at 4. So you have a 30% difference between the two and the swings look the same.

IMO, if you could look at the traces of those two swings, they would look extremely similar. However, the video would show those pressure shifts happening at different points in the swing.

[iacas]

I just want to add quickly one thing: both the SwingCatalyst and the SAM Balance Lab measure the exact same things in the exact same way. Both can be thrown off if you don't sync your video (you have to sync each video, though the SwingCatalyst will tie to a FlightScope or Trackman so it will set impact correctly when it's tied to that, and more accurately estimate the other two), but on both the traces and the numbers were virtually identical.

One system is not particularly better than the other (the SwingCatalyst software may be slightly better, given its abilities to tie into more components), and this video does not exist to promote one system over the other as both are great. Both measure pressure - as I've been saying for years now you cannot measure "weight" in a dynamic (moving) system.

[cjack]

Originally Posted by iacas

I just want to add quickly one thing: both the SwingCatalyst and the SAM Balance Lab measure the exact same things in the exact same way. Both can be thrown off if you don't sync your video (you have to sync each video, though the SwingCatalyst will tie to a FlightScope or Trackman so it will set impact correctly when it's tied to that, and more accurately estimate the other two), but on both the traces and the numbers were virtually identical.

One system is not particularly better than the other (the SwingCatalyst software may be slightly better, given its abilities to tie into more components), and this video does not exist to promote one system over the other as both are great. Both measure pressure - as I've been saying for years now you cannot measure "weight" in a dynamic (moving) system.

This is not entirely correct. SAM for the most part uses a much lower grade camera to process video than SC does. This means that the camera latency will have a much higher impact on sync issues in SAM, then in SC which only ships with high speed cameras.

It is true that SC is dependent on setting the impact correctly, but this is only if you have the motion plate installed (you do if the rotational force graph is showing). This utilizes an NI box to process data, and unfortunately the timestamps are in a completely different format than the other data segments used in SC - this is why the impact must be set correctly, because there is no other way to sync (as of know).

On the other hand, if you only use a forceplate (shows pressure distribution, but does not incorporate weight or lateral torsion in the plate), the center of pressure graph syncing with the video is completely independent of bookmarks in SC, and will be extremely accurate.

In other words, SC will generally be much more accurate and consistent than SAM. I've spent a lot of time researching these programs, so just wanted to clear this up.

[Harmonious]

Going back 15-20 years or so, a golf magazine did some similar (although certainly not as technically advanced as Swing Catalyst) testing of the weight shift during pro swings using standard scales. The more things change, the more they stay the same....

[iacas]

Originally Posted by cjack

This is not entirely correct. SAM for the most part uses a much lower grade camera to process video than SC does. This means that the camera latency will have a much higher impact on sync issues in SAM, then in SC which only ships with high speed cameras.

I'll simply say a few things. First, we were able to get synchronized data from the SAM Balance Lab when we properly set the marker points to sync the video to the data. When done, the SAM Balance Lab data was virtually identical to the SwingCatalyst. You can use a variety of cameras with the SwingCatalyst and the SAM. In either case, though, failure to sync each swing (or confirm that the sync was done properly by the software) to the video will produce very misleading or downright nonsensical data. On that I'm certain you would agree. :)

Originally Posted by Harmonious

Going back 15-20 years or so, a golf magazine did some similar (although certainly not as technically advanced as Swing Catalyst) testing of the weight shift during pro swings using standard scales. The more things change, the more they stay the same....

As you know that isn't a very accurate test of "weight shift" (it's pressure), and that study was poorly done because it relied on analog scales. As fast as pressure is shifting during the downswing of any good or great player, an analog scale simply can't keep it. It will always lag behind. Good players can generate forces well in excess of their "weight."

[iacas]

FWIW, here are a few static photos. Guess the weight distribution in each. For simplicity, just guess the weight distribution on the left side as a percentage of total weight (again, static, so weight = pressure here).

So (and these are not the answers) you could say: 11, 22, 33 for weight left (Dave's left foot, not the left of the photo) as your answer.

[migueldds]

Originally Posted by iacas

FWIW, here are a few static photos. Guess the weight distribution in each. For simplicity, just guess the weight distribution on the left side as a percentage of total weight (again, static, so weight = pressure here).

So (and these are not the answers) you could say: 11, 22, 33 for weight left (Dave's left foot, not the left of the photo) as your answer.

I'm guessing that the weight distribution in all 3 is around 50/50 !

So , my answer is 50,50,50 .

It just looks like that could very well be the case , even though the

poses make it look ( at first ) as if there are major differences ,

Michael