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

[iacas]

You can't "push off the ground" with your left foot until the mass of the body is slightly shifted to the left. It would be like pushing off with your left foot when it was suspended in the air.

Sure you can.

Before you can put pressure on your left foot, you have to have more than 50%of your weight on your left foot. This is why all good golfers shift their weight slightly to the left during the transition.

I agree that's how it is in a good golf swing, but on its own it's not an accurate statement. You can stand with 40% of your pressure on your left foot. Keep both knees bent, then rapidly straighten your left knee. Your weight (mass) will be pushed to the right, and your pressure would spike beneath the left foot.

We see such pressure spikes forward under the left foot of poorer golfers all the time. They don't get their weight forward, they extend their left knee, and then that pushes their weight farther back.

This shift to the left is done by pressure  from the right foot.The left foot cannot thrust or spike anything until the mass of the body is slightly left.Try placing 90% of your weight on your right foot and ten percent on your left foot and try to leverage anything with your left foot. You cannot. You must move left first.That is why the pressure on the left foot is caused by the weight ( mass) of the body shifted to the left. Of course if you keep the  weight  on the left foot throughout the backswing this step is not necessary.

There's really very little pressure to shift the weight (mass) left. And virtually no good golfer is 90% of their pressure right (let alone their mass).

When the weight is on the left foot, the pressure then can be applied. But this pressure ( "using the  ground") is mainly  applied against the ground vertically. The vertical pressure  from the left foot occurs  as an upward force  and opposes the force of the arms bringing the club back to the ball as a downward force.As the club moves past the ball, the body is carried by the momentum of the club  and the arms to the finish.

You're putting a bit too much importance on some things, and using vague words elsewhere. Let's try to use precise words and say exactly what we mean.

I agree that it's "mainly" vertical if you define it as < ~ 30° or so. That's an instance of somewhat ambiguous wording.

I disagree that the body is necessarily carried through to the finish by the arms. Plus, we have muscles, and are not subject strictly to momentum.

You also said the weight was left already; it is, but in reality it's lagging behind the pressure. The weight is almost always lagging behind the pressure. Pressure shifts right on the backswing (weight follows but more slowly), pressure shifts left on the downswing but weight is again slower to get there.

So let's use our words very carefully, and clearly.

[william1943]

If you look at the woman in the video you will see that at the transition she moves her weight to the left.Her hips move left. And the pressure on left foot  reaches 50%  by the  time her left arm is horizontal to the ground  in the down swing.A tiny arm movement. SO the weight has moved left but the pressure has only increased to 50% in the left foot. Clearly the weight has moved left BEFORE the pressure reaches 60 or 70 percent. The pressure has been reduced

on the right leg by moving the hips left. It is not a dramatic visual event but it is the reason her right leg has reduced pressure and  the pressure on the L leg has risen quickly .

At this midpoint in the downswing point, her weight( pressure) is 50:50 and the L arm is horizontal to the ground. From this point all she has to do is swing the club thru and this movement rapidly releases the pressure on the right foot as the mass of the arms and club creates momentum that causes the weight to flow along  to the left leg. and the pressure on the L leg increases  as this happens.

Try this;

Stand with both feet evenly balanced with 50 :50  pressure and weight  on both legs. Now move your arms in a  backswing   motion( no club needed) till the L arm is hallway back  parallel to the ground. Pause and  get the weight 50 50 again.Some pressure will be needed in the r foot to do this.  A little. A tiny bit.

Now keeping  the pressure the same  with your legs relaxed  swing your arms from right to left as in a ball strike downswing.

You will see that this motion will  cause your weight to move all the way to your left leg.

The arms swinging cause the hips to turn and open up towards the target and the weight  and pressure to move left.

The faster you do this  move, the faster your weight will transfer and the faster your hips will turn.

If you do this exercise  with the weight 70% on the right leg and try to swing your arms, you will not be able to get the weight to  flow

to the right leg.  ( Unless you quickly precede  this movement with a shift of the  weight to the L leg.)

This is why balance is so important . If you don't get the weight rebalanced as the downswing strike occurs,you will never quickly reach

the 90% left pressure impact position so important . And this will slow your swing down. Video observation of all   top pros  shows this to happen. They get their body mass 50 50 by the end  of the transition  and ready to strike.

Weight transfer proceeds pressure accumulation in the L leg

Hips follow the arm swing as the arms create a flow of mass  towards the L leg.

A consequence of this is the observation that speeding up your hips will never speed up  your swing speed. But speeding up your arm swing

will cause your hips to open up faster ( unless your hips are unable to keep up.)  So fast hips are seen in good golfers BECAUSE  they have

a fast arm speed. Fast hips  without fast arms will only get you "stuck" behind you, causing all kinds of problems.

So the sequence is " weight moves left, arms swing down, hips open hip to allow the arm swing to keep moving to the finish. Staying in balance is  essential.

'Thanks for the video of the pressure measurements.  I have learned a lot. Keep up the good work. It  would be good to  have more examples to look at.Perhaps we would see something different in Rory,Tiger, Phil, Ernie.  It would be interesting to see these measurements

in long hitters like Bubba. and looking at sand play might be interesting. Henrik Stenson seems to just stand there and swing with his arms

land just smash it with title follow thru. He would be interesting to test.

[iacas]

If you look at the woman in the video you will see that at the transition she moves her weight to the left.Her hips move left. And the pressure on left foot  reaches 50%  by the  time her left arm is horizontal to the ground  in the down swing.A tiny arm movement. SO the weight has moved left but the pressure has only increased to 50% in the left foot. Clearly the weight has moved left BEFORE the pressure reaches 60 or 70 percent. The pressure has been reduced

on the right leg by moving the hips left. It is not a dramatic visual event but it is the reason her right leg has reduced pressure and  the pressure on the L leg has risen quickly .

At this midpoint in the downswing point, her weight( pressure) is 50:50 and the L arm is horizontal to the ground. From this point all she has to do is swing the club thru and this movement rapidly releases the pressure on the right foot as the mass of the arms and club creates momentum that causes the weight to flow along  to the left leg. and the pressure on the L leg increases  as this happens.

William, weight is not the same as pressure. In 5SK we use the word "weight" but we really don't mean mass, we mean force. By A5 (left arm horizontal) her weight is probably close to 50/50. Then she goes to 60 and 70 and even 75 left, but the weight lags behind. That's force, not weight (mass).

Stand with both feet evenly balanced with 50 :50  pressure and weight  on both legs. Now move your arms in a  backswing   motion( no club needed) till the L arm is hallway back  parallel to the ground. Pause and  get the weight 50 50 again.Some pressure will be needed in the r foot to do this.  A little. A tiny bit.

William, moving your arms might make you 52/48. It takes next to nothing to get your weight back to 50/50. A movement you won't even be able to see, basically.

Now keeping  the pressure the same  with your legs relaxed  swing your arms from right to left as in a ball strike downswing.

No it won't. You have to make your weight move there. Your arms swinging alone will not do it.

[boogielicious]

And what do you think happened other than  he got wet.?

He was not able to generate any ground forces, so his swing was very short.  And he got wet.

[william1943]

Boogie,

What are  "ground forces" and how do you  generate them?

William

[boogielicious]

Boogie,

What are  "ground forces" and how do you  generate them?

William

Start at the beginning of this thread and work your way back to here.  It will answer all your questions.

[iacas]

Also…

Boogie,

What are  "ground forces" and how do you  generate them?

William

2. In physics, and in particular in biomechanics, the ground reaction force (GRF) is the force exerted by the ground on a body in contact with it.

3. Ground reaction force - Wikipedia, the free encyclopedia

   en.wikipedia.org/wiki/ Ground _ reaction _ force

   Wikipedia

[Abu3baid]

He was not able to generate any ground forces, so his swing was very short.  And he got wet.

I have to agree with the other poster here.. I don't think that proved anything really other than you get wet when jumping into a pool... Of course he wouldn't be able to make a full swing falling down, as you can see the whole way down other than when he took the club back he was thinking about the landing..

[jamo]

Boogie, What are  "ground forces" and how do you  generate them?  William

Simple answer: If you had to jump as high as you could, would you rather jump straight-legged or bend your knees and spring up? The springers are utilizing forces.

[boogielicious]

Quote:

Originally Posted by boogielicious

He was not able to generate any ground forces, so his swing was very short.  And he got wet.

I have to agree with the other poster here.. I don't think that proved anything really other than you get wet when jumping into a pool... Of course he wouldn't be able to make a full swing falling down, as you can see the whole way down other than when he took the club back he was thinking about the landing..

Eyad,

the video was really more tongue & cheek than anything else.

[billchao]

I have to agree with the other poster here.. I don't think that proved anything really other than you get wet when jumping into a pool... Of course he wouldn't be able to make a full swing falling down, as you can see the whole way down other than when he took the club back he was thinking about the landing..

He's making a point about ground forces and demonstrating how weak a golf swing would be without them. Even the most "armsy" swing depends on the interaction of the body with the ground to generate power. Just look at the way he has to flip at "impact" just to swing the club through to some sort of finish. Every swing needs ground forces, even if people aren't feeling them. We all know feel ain't real :-)

[Ernest Jones]

Ground forces are what keep you from being swallowed by the earth.

[william1943]

OK. SO ground reaction forces are the force that the ground exerts on a body on top of it.Good.  SO if you weigh 150 pounds the ground

reacts with 150 pounds  of ground reaction force.  Now the next question is how do  you "generate" ground reaction forces. beyond those obtained by simply standing still in a golf swing. Obviously

if you want to generate MORE ground reaction  forces  you obviously must jump up and down to do so. If you jump up and down on a scale the weight reading  will exceed your

body weight for an instant . Exceed your resting baseline ground reaction forces.SO in a golf swing to generate ground reaction forces we must jump up and down.  I guess this is what causes the head of good players to go up and down.

Correct.?Like in skiing  we bend our knees and jump up a little ( so called "unweighting") to allow the skis to turn. You can unweight without actually having your feet leave the ground.

Now this brings up a question regarding the pressure measurements in the video. The pressure measurements  do not measure ground reaction forces ( in pounds for example as a scale would read them).The pressure measurement only record the RELATIVE  pressure DISTRiBUTION between the feet. Not the absolute  pressure or weight in the feet.  You could conceivably

generate more ground  reaction forces  while maintaining the same relative pressure in your or swing  and the increase of GRF would not show up

;

SO these pressure measurements in the video are not measuring  absolute ground reaction forces. Just relative pressure distribution.

Other than the head moving up and down how can you determine if any golfer is generating ground reaction forces and how can you measure them? I assume  the answer is that you cannot.

The girl in the video did  not  move her head up and down like  Tiger and Johnny Miller  for example. .. Does that mean she did not generate any ground reaction forces..

To me this seems like a very advanced move.

[iacas]

GRF is the general term for all of this stuff.

You can generate more GRF without actually leaving the ground. Pressure plates COULD be tuned to actually display the GRF values, but the percentages and COP traces are more valuable for golf instruction.

[golfrocks]

do you think the tour pros have more weight on the heels or toes at impact

[iacas]

do you think the tour pros have more weight on the heels or toes at impact

On the front foot, it can vary, but it tends to be a little toward the heel.

On the back foot, almost always entirely on the toes.

[golfrocks]

oh ok caUSE I HAVE TO MUCH WEIGHT ON MY HEELS AT IMPACT

[Ernest Jones]

oh ok caUSE I HAVE TO MUCH WEIGHT ON MY HEELS AT IMPACT

@golfrocks

Please put a little more effort and care into your posts. The above is sloppy and hard to read for no reason other than laziness. I think you'll find less and less people replying to your posts if you continue to show a lack of courtesy in your writing. I'm not picking on you, I'm trying to help you.

You can take or leave this advice...

Not to beat a dead horse, but here is another example:

Is that y my path is to much in to out

If you can't be bothered to read your own post before submitting it, why would you expect others to read it? There is also an Edit function (little pencil at the bottom of your post - you have a few minutes to use this tool) that will allow you to make corrections once you have already hit submit. Typos and misspellings are fine, but ALL CAPS ALL THE TIME or caps THAt coME ON and off and all other sloppy and preventable stuff should be cleaned up before hitting "submit" or edited if you only notice after the fact.

FWIW, I proofread all my posts before submitting and usually double check after submitting as well. It's a courtesy to the readers. I still make mistakes but people appreciate the effort to minimize them. There may even be mistakes in this rely, lol.

Cheers,