Who Pushes Off With Their Trail Leg?

[billchao]

20 minutes ago, drabby1980 said:

That does not prove what you think it does.

Yes, it does. A push would exert more force into the ground, not less.

20 minutes ago, drabby1980 said:

Pushing off the trail foot would shift the weight to the other side as it's a pivot point.

A push can shift pressure forward, it's just not how it's done in high level golf swings. A push with the trail foot would increase the pressure significantly in that direction and "unweight" the lead foot slightly, which is the opposite of what is happening.

The pressure shift comes from the core. This stuff has been actually measured by people who study these things, using electrodes to detect muscle activity.

23 minutes ago, drabby1980 said:

There is clearly a lot of pressure on the trail foot initially and that pressure and "push" moves it, which is the OP point. 

Shift != push. Stand upright with your weight evenly distributed. Lean left. You just shifted your pressure and you didn't have to push off your right foot to do it.

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I'm also going to ask you to keep your comments relevant to the topic, thanks.

[drabby1980]

8 minutes ago, billchao said:

Yes, it does. A push would exert more force into the ground, not less.

 

Not true at all.  There is also significant pressure on the trail foot loaded, the push shifts the weight to the lead side.  If the weight were not already loaded on the trail foot you would have a point.  Again, you are making assumptions and stating them as fact.  All of my posts have been on the topic of the discussion.

 

Edited June 8, 2019 by drabby1980

[billchao]

11 minutes ago, hoselpalooza said:

BOOM! i'm just presenting more data. listen to this starting at 1:07.

There's still no push. He's talking about shearing, which is more like standing on a lazy susan and trying to spin it with your feet. It changes where the pressure is focused, but watch the pressure map. Pressure on his right foot is still greatest at the top of the backswing. A push will not decrease the pressure.

16 minutes ago, hoselpalooza said:

is exactly what i've been talking about.

That's not what you've been talking about at all. You started by talking about a lateral push like off of a baseball rubber. First, you said you pushed off the inside of your trail foot. Then you said it's like pushing off of your heel. Then it was pointed out that your heel lifts fairly quickly in your swing, you changed it to your toe. Now you're saying you meant something else entirely? Nobody knows what you've been talking about at this point, you've changed it so much.

[drabby1980]

11 minutes ago, drabby1980 said:

Not true at all.  There is also significant pressure on the trail foot loaded

 

Meant there is already significant pressure on the trail foot.

[iacas]

14 minutes ago, drabby1980 said:

Not true at all.  

Very true. Simple physics. If you pushed the pressure would spike under the pushing foot, just like it does under the lead foot from ~5.5 to 7. It does not spike.

You two are arguing that 2+2=7.

[drabby1980]

7 minutes ago, iacas said:

Very true. Simple physics. If you pushed the pressure would spike under the pushing foot, just like it does under the lead foot from ~5.5 to 7. It does not spike.

You two are arguing that 2+2=7.

The weight is already loaded, so there would not be additional pressure.  You are wrong here.

[hoselpalooza]

more data from boditrak. 

some comments reaffirming what i've been saying all along:

Quote

As Cordie approaches the top of the swing, he has over 90% of his pressure on his trail side, mostly concentrated under his heel. This is a pretty elite position, especially considering that Cordie doesn’t have much sway [if you want to see a great example of this on TOUR, check out TPI’s Dave Phillips analysis of Jason Day]. From here Cordie can push off into his lead side and generate plenty of speed. We’ve often used an analogy of a sprinter in starting blocks: A sprinter must pushes into starting blocks to send their center of mass in an opposite direction.

How To Analyze A Pressure Trace With Dr. Sasho MacKenzie - BodiTrak Performance

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Dr. Sasho MacKenzie is a professor in the department of Human Kinetics at St. Francis Xavier University

 

[iacas]

2 minutes ago, drabby1980 said:

The weight is already loaded, so there would not be additional pressure. You are wrong here.

Nope. 😉 Try again. Pushing would increase the pressure. It’s not at 100% so there’s room for it to increase. It decreases.

[drabby1980]

1 minute ago, iacas said:

Nope. 😉 Try again. Pushing would increase the pressure. It’s not at 100% so there’s room for it to increase. It decreases.

Swing and a miss buddy.  The pressure increases through the backswing and the push transfers it to the lead.  The peak is the push.

[iacas]

3 minutes ago, drabby1980 said:

Swing and a miss buddy.  The pressure increases through the backswing and the push transfers it to the lead.  The peak is the push.

That is still in the backswing.

Look at the force vectors. Look at the video with the dolly.

[drabby1980]

2 minutes ago, iacas said:

That is still in the backswing.

Look at the force vectors. Look at the video with the dolly.

I have reviewed it, this is milliseconds that you are trying to draw a line on.  The push is beginning at the peak weight on the trail foot.  That is how the weight is able to transfer so quickly to the lead foot.

[hoselpalooza]

2 minutes ago, iacas said:

Nope. 😉 Try again. Pushing would increase the pressure. It’s not at 100% so there’s room for it to increase. It decreases.

this is comically wrong. are you saying that dr. satosho mckenzie, terry hashimoto, scott hamilton, etcetera, are reading the traces wrong?

also, this is at 100%: 

Just now, iacas said:

Look at the force vectors. Look at the video with the dolly.

this one video only demonstrates what's going on for that particular golfer. i never said that all golfers push off with their trail foot. 

4 minutes ago, drabby1980 said:

I have reviewed it, this is milliseconds that you are trying to draw a line on.  The push is beginning at the peak weight on the trail foot.  That is how the weight is able to transfer so quickly to the lead foot.

the term i've seen is "peak velocity", and in the traces i've shared you will notice peak velocity occurs when the majority of pressure is still on the trail foot. this is what the analysts have said represents the pushing off move to shift pressure from the trail foot to the lead foot.

more info from another source who uses force vectors:

Quote

3) Top of the backswing (the club stops, changing direction from backswing to downswing): In this frame, the right foot already started pushing hard toward the target.

 

Push hard to get more acceleration | dbprogolf

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The ground reaction force (GRF) is the force exerted by the ground on a body in contact with it. Recalling Newton’s 3rd law: “For every action, there is an e...

 

[iacas]

At this point I could take two hours, make an incredibly detailed post with video, images, citations, phone calls with PhDs, and you’d both just keep arguing that 2+2=7.

Bye @golfonly part deux.

P.S. To other members, drabby1980 is the formerly banned member @golfonly.

[hoselpalooza]

also, the last trace shows 100%? if this isn't proof, what is?

[billchao]

@drabby1980 has been removed from this conversation, as it has been discovered that he is a previously banned member on a different account known for trolling.

[iacas]

1 minute ago, hoselpalooza said:

also, the last trace shows 100%? if this isn't proof, what is?

It’s proof he unweighted his left foot.

[hoselpalooza]

2 minutes ago, iacas said:

It’s proof he unweighted his left foot.

first you say that it needs to be at 100% to indicate pushing and then when i show you something at 100% you say it's proof the trail foot is unweighted. seriously? and what about peak velocity?

you're completely ignoring valid data as well as the analysis of other qualified professionals. and you're saying i'm trying to make 7 out of 2+2? this makes no sense. 

[billchao]

3 minutes ago, hoselpalooza said:

first you say that it needs to be at 100% to indicate pushing and then when i show you something at 100% you say it's proof the trail foot is unweighted. seriously?

@iacas never said the trail foot has to be at 100% to indicate pushing, and he said the left foot is unweighted.