Your Center of Gravity

[Grasshopper]

How low is your center of gravity? Do you think your COG relative to your opp's matters?

[Purple Fencer]

I don't know how it relates to my opponents....but it certainly appears that it's moving down closer to my butt!

[ThatReallyHurt]

For me, I try to scrunch down as low as I reasonably can, but I think that it really comes down to how accustomed you are to your own CoG and the limits it places on you...

[PalmFrond]

I seem to remember, from long-ago martial arts classes, that your centre of gravity is about three fingers' width below your navel (known in chinese as the dan tien), and it is the point about which you rotate when in free fall.
I'm told that the relatively low centre of gravity of short fencers (such as myself) helps with quick movement up and down the piste, although taller fencers can move just as quickly. They just need to work harder at it.

Or all of the above could be total nonsense.

[kalivor]

The lower your centre of gravity, the easier it is to make sudden accelerations/changes in direction.

So yes, it matters. And having a lower one than your opponent would be an advantage.

[glowstix]

Originally Posted by Grasshopper

How low is your center of gravity? Do you think your COG relative to your opp's matters?

for me, i try to get as low as possible, i tend to move better. i've heard the advice before that being more upright may be better in epee but that doesn't serve me. if you're more upright, you tend to bob up and down and not move as well. i'm not that much of a bouncer in epee, i tend to stay lower and i still move better than most of my opponents (all but one actually). for some taller opponents, i'll experiment with standing a bit more upright but i haven't decided as to whether or not it has actually helped things..

[sloper]

Originally Posted by kalivor

The lower your centre of gravity, the easier it is to make sudden accelerations/changes in direction.

So yes, it matters. And having a lower one than your opponent would be an advantage.

I think there are times, especially in sabre, where a higher center of gravity can be an asset - if you are strong enough. For instance, consider the speedy back and forth actions in saber that are generated more with the torso than the legs. An example is the fleche (flunge). The higher your center of gravity the sooner you can harness extra momentum as you throw yourself into the action. The caveat here is that you have to be strong enough to control your body during the acceleration and be able to get your legs caught up by the end. Everybody has seen teenage sabre fencers who have reached their adult height but not their adult strength. When they fence, it can look awkward and flail-ly. But give them a few years and it's a different story.
This may also explain why women sabre fencers don't fleche like men do. Having a lower center of gravity, they would have to achieve a more extreme angle of lean to accelerate in the same fashion, and getting their feet back under them in time would be even more difficult.
In fact, differences in centers of gravity could explain the different overall look of women's and men's sabre fencing. Strong, fast women's sabre fencers always look centered and solid to me, while the strong, fast men's sabre fencers look down right acrobatic.

[telkanuru]

The way I learned to infight was he who keeps his CoG low gets the touch. I keep mine fairly low, and I "bounce". It's good for preperations, lunges, and fleches.

[kalivor]

Originally Posted by sloper

I think there are times, especially in sabre, where a higher center of gravity can be an asset - if you are strong enough. For instance, consider the speedy back and forth actions in saber that are generated more with the torso than the legs. An example is the fleche (flunge). The higher your center of gravity the sooner you can harness extra momentum as you throw yourself into the action. The caveat here is that you have to be strong enough to control your body during the acceleration and be able to get your legs caught up by the end. Everybody has seen teenage sabre fencers who have reached their adult height but not their adult strength. When they fence, it can look awkward and flail-ly. But give them a few years and it's a different story.
This may also explain why women sabre fencers don't fleche like men do. Having a lower center of gravity, they would have to achieve a more extreme angle of lean to accelerate in the same fashion, and getting their feet back under them in time would be even more difficult.
In fact, differences in centers of gravity could explain the different overall look of women's and men's sabre fencing. Strong, fast women's sabre fencers always look centered and solid to me, while the strong, fast men's sabre fencers look down right acrobatic.

That's ... nonsense. In a fleche or flunge, obviously balance is not important, and the centre of gravity plays little role. However, the acceleration from the flunge or fleche comes from the legs, not from falling forward. The legs need to be bent in order to get that push (though I suppose they can be bent *too much*).

The difference in the ability to fleche and flunge between men and women has to do with explosive leg strength, not with the centre of gravity. It's similar to the difference between men and women sprinting.

[Fechter1]

If a lower COG was really such an advantage, you'd see fencers duck-walking all the time, right? (After all, you can't get your COG much lower than that)

What really matters, as mentioned before, is the ability to accelerate your COG laterally. For that, it is more important that your legs are at (or close to) the power angles (the angle of knee bend that allows your quads to generate the most power, IIRC that's just around 60 degrees).

And in that same vein, balance, especially in a fleche (or flunge, for the crossing-impaired), is extremely important.

But that's just what I think

[kalivor]

Originally Posted by Fechter1

If a lower COG was really such an advantage, you'd see fencers duck-walking all the time, right? (After all, you can't get your COG much lower than that)

What really matters, as mentioned before, is the ability to accelerate your COG laterally. For that, it is more important that your legs are at (or close to) the power angles (the angle of knee bend that allows your quads to generate the most power, IIRC that's just around 60 degrees).

And in that same vein, balance, especially in a fleche (or flunge, for the crossing-impaired), is extremely important.

But that's just what I think

"Such an advantage?" It's ONE advantage. Reach is also an advantage. So is having your legs at angles that maximise your power. The question was: "Is it an advantage?" The answer is "yes," because it improves acceleration and changes in direction.

I mean, if it was the only thing that mattered, we could forget the duck-walk and just lie on the floor ...

[mlr2fence]

Originally Posted by glowstix

for me, i try to get as low as possible, i tend to move better. i've heard the advice before that being more upright may be better in epee but that doesn't serve me. if you're more upright, you tend to bob up and down and not move as well. i'm not that much of a bouncer in epee, i tend to stay lower and i still move better than most of my opponents (all but one actually). for some taller opponents, i'll experiment with standing a bit more upright but i haven't decided as to whether or not it has actually helped things..

The one who moves better--she/he a 'bouncer'? I would think that bouncing would tend to make for a higher COG.

[jBirch]

The blanket statement, "a low centre of gravity is best" is incorrect. What matters is, as was previously stated, your ability to use your centre of gravity to effect changes in distance and timing.

Your centre of gravity is the point around which your body moves. It has inertia when it moves that must be countered with force in the opposite direction (or else you fall down).

A static and "centred" COG allows you the most options in motion but requires you to expend effort to move your COG in the direction of advantage. How much effort depends on the muscles involved and their ability to generate force along the vector of interest. You can have the same COG standing on your head as standing on your legs, but the muscles involved in generating useful force are totally different. In fencing, the ability to change direction is of utmost importance, not your ability to rapidly move continuously in one direction or another and so our footwork strives for a constantly centred COG.

A fleche, for example, requires the ability to move your COG extremely far forward in order to get you in "balance" in flight with your hand leading and feet trailing. (If you don't, you rotate in flight and end up doing a front flip, usually resulting in a violent introduction of face to floor). You also need to be able to arrest that momentum by moving your COG back centred as quickly as possible. In this effort, your quads and hams act as "shock absorbers" on the landing to cushion the COG's momentum and slow it to a stop. Only once the COG has zero inertia, can it be moved in the opposite direction. This is why the fleche ends with a cross over.

Keeping your COG "centred" is the key, not keeping it low or high. There are lots of ways of moving that keep your COG "rotating" in order to have it used to maximum effect, but that's the realm of gymnasts and dancers. Fencers are really operating in a linear realm (as much by virtue of the wires as anything else) and so are most concerned with getting that COG to move in opposite directions. Hence staying centred as long as possible is one of the goals our footwork strives for.

Now, when you say, low COG what you're really meaning is "wide base". That your COG is equally centred over your cocyxx and your legs are extremely stable. This balances your upper body and allows you to hold your back/head erect without "bouncing" your COG up and down, front to back or side to side when you move. The advantage to this is again that your COG remains "centred" for as long as possible. This is good so that you can use force most efficiently to start its inertia in one direction or another. When you generate less inertia you can rapidly change that inertia as the situation dictates. Essentially, you can change velocity quickly. If you go too low though, your body mechanic requires you to first raise up before moving forward/backward which defeats the whole purpose of a centred COG. The clearest example of a ridiculously low COG is a fully extended lunge (or even the splits!). Can you continue to move freely while in a very deep lunge?

So the answer is that your COG needs to be in the correct place for the action that you are attempting and it has to have the correct inertia to effect the proper timing. This needs to be balanced with your muscles (legs) ability to apply force to that COG in as efficient a manner as possible.

Obviously, as relates to your second question, this is of paramount importance as it relates to your opponent's distance, timing and inertia to allow you to make the most advantageous movement at the most advantageous time.

All of this, of course, is centred around the ability to move, not the attempt to hide target. In that latter regard, sometimes you want to be barely in balance, your COG in some weird place, so that you can have the least target area exposed. When you do this though, you generally trade your ability to move in order to decrease your opponent's ability to score. Again, as relates to your second question, even when you're doing weird contortions, they only matter as it relates to your opponent and their available options.

Hope this helps.

James.

[Sciurus-Rex]

I keep my center of gravity at home in a box so it won't be broken.

[glowstix]

Originally Posted by mlr2fence

The one who moves better--she/he a 'bouncer'? I would think that bouncing would tend to make for a higher COG.

exactly! my CoG is low and i did say i didn't bounce that much. whenever i do, it tends to make me "stand up" a bit and i don't want that.

[Sciurus-Rex]

Originally Posted by mlr2fence

I would think that bouncing would tend to make for a higher COG.

Nope. You'd think wrong.

[sloper]

Here's part of an interesting article I found on basketball conditioning and center of gravity. The full article is at http://www.powerbasketball.com/050815.html

"Basketball requires stop and go movements, jumping and landing, and giving and receiving force (setting or getting picked). All of these require dynamic balance and stabilization of the body. Core training will help control your center of gravity, increasing your ability to change direction in the most efficient way possible. ... The center of gravity is located in a speculative balance point around what is called your center of mass. ... In order to move, your center of gravity must be shifted outside of your balance threshold (where your body can no longer balance itself) (Foran, 2001). You must regain your balance, and shift it again to change a different direction. ..."

The 55-60% figure is for men. For males, center of mass is in the upper abdomen. In females, it's in the hips or low abdomen.

By leaning at the waist, the male athlete has shifted his COG where the female athlete has not yet. This enables strong, fast male fencers to initiate actions requiring extreme changes of direction more quickly than strong, fast females.
Difference in explosive muscle strength is simply not the whole story when it comes to the different look of men's and women's sabre fencing. COG is a big factor, too. It may be hard to consider because it can't be "worked on" in any individual. You can increase your strength, speed and lactate threshold but you can't change your COG.

The difference in the ability to fleche and flunge between men and women has to do with explosive leg strength, not with the centre of gravity. It's similar to the difference between men and women sprinting.

I think sprinting is a poor comparison for the initial acceleration that characterizes the actions I'm talking about. Sprinting (100m) lasts a comparative eternity and is a cyclical activity where force is generated continuously in the same direction. I would guess, though, that men start sprints faster - partially due to the fact that in the starting position, their COG is further past the balance point than women's are.

[telkanuru]

Originally Posted by glowstix

exactly! my CoG is low and i did say i didn't bounce that much. whenever i do, it tends to make me "stand up" a bit and i don't want that.

This is a habit that needs to be overcome, not a side-effect. Bouncing and CoG have very little to do with each other. I can bounce from basically any en guard position. Granted, it takes a little bit of extra leg muscle to do it from a low en guard, but you get used to that. As a blanket statement, a low CoG is good for fine distance control but tends to limit overall mobility, while I higher CoG is better for loose distance control and increased mobility. You tend to see these extremes more in epee, with Foil/sabre fencers taking the middle path.

Tangentially, glowsitx, if those pics in the gallary are of you, your CoG isn't all that low. Just sayn'...

I am somehow reminded of Paul Soter quoting someone (Alex Abend, I think?) saying that the American school of fencing is defined by crappy footwork.