Ground Reactive Forces and "Jumping" for Power

[iacas]

Many of you will remember the many times I've said I almost couldn't care less about Tiger's head "dipping" during his swing. Many of you might not have known why I thought this wasn't a problem, and some of you knew... What's some schmuck on the Internet know when Peter Kostis, Nick Faldo, Johnny Miller, Brandel Chamblee, and goodness knows who else were all talking about what a bad, terrible thing it was?

Tiger's dipped his whole career. He dips when he wins and he dips when he's not winning. The dip is not a swing flaw, and here's a post and thread I've been planning for awhile...

I'm going to start off with two videos:

Next, here's a link to an abstract for a 2001 paper on parametric acceleration (Miura, K. (2001) Parametric acceleration--the effect of inward pull of the golf club at impact stage. Sports Engineering 4, 75-86.)

Now, consider these things:

• Jamie Sadlowski bends his left arm coming into impact.
• Tiger Woods dips his head quite a bit and then raises it and straightens his legs coming into impact.
• One of the pieces of nearly every good swing pattern (particularly with longer clubs) is to "jump" coming into impact.
• Ben Hogan had an extra cleat installed on his right foot so that he could drive forward and jump on the downswing.

There are two points here. The first is "jumping," and I'll talk about that briefly. First, "jumping" is not limited to "new" swings (like S&T;). Every swing uses jumping and extension or else you'll be bent forward, your head would be moving all over the place, and you'd have a heck of a time hitting the ground consistently. You'd swing the slowest, your divots would tend to be heavy, thick clumps of sod, and you'd quit the game.

Around P6 (club horizontal to the ground on the downswing), the clubhead starts to get heavy. It's being thrown, pulled, or generally moved towards the ground at a really high speed. Jumping and extending - by pushing the hips forward, straightening the legs, and feeling the left side of your body expanding as you push forward and rotate - helps to shallow the club's angle of attack and exit.

Between roughly P5 and P6 most golfers have (or should) regain roughly their address flexion in their knees and hips, so this sudden jumping move helps to "throw" or "kick" the clubhead at the ground, similar to how one continually yanks on a string attached to a rock to keep the rock twirling in the air.

The very act of "jumping" creates some of the parametric acceleration I've talked about. It's what "kicks" the club. Everyone should do this in their golf swing, and we teach it to the majority of people in our schools and individual lessons.

But if you want to super-charge your parametric acceleration, and REALLY add some extra kick to the clubhead, then you need to do more. You need to make the distance from your left shoulder to the ball smaller, THEN yank upward (which is "inward" relative to the circle at impact). (If you did nothing but yank without first shortening the distance, you might just swing right over the top of the ball.) Sadlowski "yanks" on the handle of the club by bending his left arm. Tiger shortens the arc by squatting down quite a bit and dropping his head so he can JUMP more.

How much power can you add? Standard jumping with no change in levels? 5% or so is a reasonable estimate. 10% is possible if you compress into the ground like Tiger.

The downside? There's little in the simple jumping I teach, because your upper swing center around which your shoulders are rotating stays fairly constant, but if you want the added boost of compressing and THEN exploding, ball contact may suffer. We've all seen Tiger Woods pop up the occasional ball, particularly with the smaller-headed 3W. Changing your levels down and then trying to time the explosion upward is difficult, and most of the time Tiger gets it but sometimes he doesn't. For Tiger, the tradeoff is worth it. Most of the time.

Here's a video of J.B. Holmes dropping his head significantly, and you might say he doesn't do any of the "jumping" or "yanking up" part, but remember the golf ball is on the side so "inward" pulling is also, in a down-the-lineview, to the left, and J.B. Holmes pulls hard to the left with his hips (this is part of the "clear your hips to get power" train of thought - downside is too many people get their hips open too early and end up coming well over the top with not enough forward drive... and their sequencing results in a LOSS of speed). Pause the video at the appropriate spots and you'll see it:

Here's Tiger again and you can see the compression and then the extension and jumping:

Now, do I ever use the second level of PA, the actual downward compressing and then exploding? Yes. If there's a long par five or a long par four that's relatively open, I'll tee the ball up a bit higher (a bit more margin for error) and try to compress and then jump like crazy. When the ball's on the ground? I rarely opt to for the added boost, no.

So, in summary, EVERYONE should "jump" or "extend" or they're giving up power. Not everyone is capable of the second level of parametric acceleration, but it's important to know that it exists and can lead to some faster clubhead speeds and bigger drives, and it's important to use as much as you can up to the point where your ballstriking suffers too much.

Footwork is overlooked a lot of times in the golf swing, but since that's the only way we're connected to the ground and the ground is pretty solid, it only makes sense that we use it for power. How far do you think you could hit a golf ball in flat-soled shoes on a pond? The ground is your friend, folks.

[motteler621]

great post Erik. I really want to incorporate more of this in my swing. One question I do have is, On the video of the girl she jumps up to her toes including the back leg (I know this is an extreme example of jumping) and in the video of Tiger his back foot is jumping up on his toes (as in his heel is lifting up at impact). I know S&T; teaches to keep the back foot heel down and roll onto the instep through impact. How is one jumping when only rolling onto the instep? Does keeping your right heel down through impact limit jumping?

[david_wedzik]

Originally Posted by iacas

Now, consider these things:

Jamie Sadlowski bends his left arm coming into impact.

Tiger Woods dips his head quite a bit and then raises it and straightens his legs coming into impact.

One of the pieces of nearly every good swing pattern (particularly with longer clubs) is to "jump" coming into impact.

Ben Hogan had an extra cleat installed on his right foot so that he could drive forward and jump on the downswing.

Forgetting about golf for a second the ground is used for power in so many other sports. Off the top of my head the baskeball player who lowers himself to explode or the football players at the combines each year doing the standing vertical leap...watch them go down a ton before exploding up...same power principles. Imagine if you made them jump off of a waterbed that never provided any resistance?? They could never even leave the ground.

Originally Posted by iacas

Between roughly P5 and P6 most golfers have (or should) regain roughly their address flexion in their knees and hips, so this sudden jumping move helps to "throw" or "kick" the clubhead at the ground, similar to how one continually yanks on a string attached to a rock to keep the rock twirling in the air.

This is where the ground is used not only to push down into but to "grip" and create the horizontal forces discussed in the video as well. You can almost feel the torque as you think about it. Watch Bubba Watson here:

Some things I wouldn't attempt to teach mind you but check out the lead leg and foot...you will see the lead let stay flexed as the foot gets back to the ground and digs in for only an instant before it has to "give". The ground pushes back and that leg rockets to straight. It is in super slo-mo and you can see the speed instantly.

Originally Posted by iacas

Here's a video of J.B. Holmes dropping his head significantly, and you might say he doesn't do any of the "jumping" or "yanking up" part, but remember the golf ball is on the side so "inward" pulling is also, in a down-the-lineview, to the left, and J.B. Holmes pulls hard to the left with his hips (this is part of the "clear your hips to get power" train of thought -

How far do you think you could hit a golf ball in flat-soled shoes on a pond? The ground is your friend, folks.

The Holmes video clearly shows the horizontal forces as he uses the ground to grip and push forward and around the circle...which is a key point. Forward is not at all simply "straight" down the target line. The body is constantly turning and we play golf on a inclined plane (arc)...thus the forward part of the motion is constantly changing.

Bottom line...we discussed this topic a bit earlier and I'm glad you put up the thread...really good stuff. Simplest way to think about this is trying to hit balls normally or trying to hit balls on that waterbed with "no resistance"...the image will speak for itself.

Originally Posted by motteler621

Does keeping your right heel down through impact limit jumping?

Hi Aaron - Yep...it certainly limits it some and if we were trying to come up with the way to absolutely hit the ball the furthest we wouldn't worry about teaching it exactly that way. The banking controls many other things for the golfer though and the tradeoff in distance is not a lot...you can still push off and use the ground to a very large degree...for certain off the lead leg (in the correct sequence). Hope this makes sense.

Dave

[motteler621]

Hi Aaron - Yep...it certainly limits it some and if we were trying to come up with the way to absolutely hit the ball the furthest we wouldn't worry about teaching it exactly that way. The banking controls many other things for the golfer though and the tradeoff in distance is not a lot...you can still push off and use the ground to a very large degree...for certain off the lead leg (in the correct sequence). Hope this makes sense.

Thanks Dave.

[uttexas]

Nice slowmo of Mr. Nicklaus jumping into impact :15 to :25

[david_wedzik]

Nice slowmo of Mr. Nicklaus jumping into impact :15 to :25

Nice find here - again...even in slo-mo you can sense the speed being built up as he uses the ground to explode both up and "horizontally". Left foot is very telling.

Dave

[mvmac]

This guy really kills it. I was almost pulled into the vortex as I was recording it.

[Shanks A Million]

I "jump" a lot, and often it causes problems, in terms of extending my leg, which caused my torn ACL. My head pops up a good 2" or so. Not surprisingly, I can generate a lot of power. What about that, is there such thing as too much?

[jl923]

I'd like to incorporate more jumping into my swing. Any drills or key swing thoughts?

[Stretch]

I've been asked to jump hard enough that my feet actually leave the ground while hitting balls. This is best practiced when you are alone at the range!

[iacas]

I've been asked to jump hard enough that my feet actually leave the ground while hitting balls. This is best practiced when you are alone at the range!

I literally made someone take a golf posture, move his arms back like he was swinging a club (no club, hands not even really touching), then swing forward, slide forward, and literally JUMP what felt like four feet in the air and four feet forward. He did this a few times, then tried to have the same feeling when he swung. Pictures after were incredible and his ball flight was twice as high.

Stretch, if I remember right, you need to feel like you're jumping from P4. No recompressing - you do too much already and do it too long - so you go forward and jump immediately.

[saevel25]

Look at bubba watons, the end both feet are off the ground, jumping... That guys a monster, just a monster..

[bunkerputt]

Dude!  How in the world did I not see this thread?  I totally figured all this out on my own a year ago or so even down to the exercises in those videos  *dancing banana*

10% is on the low end of what I gained in speed from using my legs like this.  Definitely more than that in distance.  It's also why I can't hit off mats unless I have metal spikes because they're too slippery.  For irons, I don't jump so much, but with the driver, I have a number of keys that tell me I'm using my legs well.  For one, I like to feel the back foot slide towards the target along the toe.  I also know I'm hitting it deep when my left foot opens up towards the target some without any torque on my knee.  That's because I was momentarily airborne.  With the driver, I have to play it forward and teed up a little.  If not, I'll hit it with too much lag and catch it on the crown.  The extra bit forward gives me a little more space to throw the club.

[mchepp]

The question I have is how does one stand up but avoid losing the tush line otherwise known as "goat humping". I know that it can be done, but when I work on standing up I lose the tush line.

Any thoughts here?

[bunkerputt]

Originally Posted by mchepp

The question I have is how does one stand up but avoid losing the tush line otherwise known as "goat humping". I know that it can be done, but when I work on standing up I lose the tush line.

Any thoughts here?

Don't stand up with the lower back.  Stand up with the legs.  You have to squat down first, though.

[iacas]

Originally Posted by mchepp

The question I have is how does one stand up but avoid losing the tush line otherwise known as "goat humping". I know that it can be done, but when I work on standing up I lose the tush line.

Any thoughts here?

Michael, I'm happy to expand upon this if you'd like, but I have a hunch you'll get this:

Secondary axis tilt at P7 when rotated through to the finish accounts for keeping the head and butt on the wall while still allowing you to extend (push your belt forward). In other words, it's the "forward" motion of the hips that keeps the butt on the wall in the follow-through.

[Leftygolfer]

Nice post Erik.

This is something I considered the difference from long players to average.

One question.  Does increasing your inclination to the ground (being more bent over) allow you to utilize the power in your legs more.  When I have more of an angle it seems this corresponds naturally with a steeper swing plane.  This steeper swing plane allows you to drive the club down as your spine goes from flexed to extend, and also having more time distance to create speed.

The feeling I get when I have more of a lean (I really stick my butt out and tuck in my stomach at address) is that I am in a better position to use my legs.  They feel loaded.  Then if I turn my shoulders steeper I feel alot more of my muscles loading in my hamstring and back.  I know feeling isn't always real, but is that the way it feels to have a less flat shoulder turn.  I apoligize in advance for the off topic post, just trying to understand how I got to the point where I don't have fun playing because I've gotten so irratic.

One thing I've noticed with great (long can hit the ball consistantly) is at impact they are looking down.  They aren't looking out at the ball, there head is facing the ground where the ball used to be.  You can't be in that position with a really flat swing.

[iacas]

Originally Posted by Leftygolfer

One question. Does increasing your inclination to the ground (being more bent over) allow you to utilize the power in your legs more. When I have more of an angle it seems this corresponds naturally with a steeper swing plane. This steeper swing plane allows you to drive the club down as your spine goes from flexed to extend, and also having more time distance to create speed.

At setup? I suppose it could, but you'd have a heck of a time getting set up comfortably because your distance to the ball would change, necessitating a wildly different arm angle at impact versus setup, and so on.

So I'd say that within a small range, sure, but once you get out of that it's not worth it.

Originally Posted by Leftygolfer

I apoligize in advance for the off topic post, just trying to understand how I got to the point where I don't have fun playing because I've gotten so irratic.

Could be that you've overdone it and you're having trouble timing things.