SWORDDUELING.COM

O’ beautiful fine sword lady – what clubs do you dance at?

Yuen Woo-Ping must get up every morning and cry because he’s 64 and can’t brawl daily. The man clearly loves fighting. Just look at this scene he choreographed for Fist of Legend, where Jet Li reprises Bruce Lee’s role from Fist of Fury:

It starts out in a pretty standard Chinese mode, both opponents loitering well inside striking range, checking each other’s arms and doing block-punch one-two (in between all the showy aerial techniques). But once Jet Li gets serious, he switches to a Western-influenced style — dancing in and out of reach, sniping at Chin Siu Ho with long punches, and throwing boxing combinations. Look at the double right jab to left cross! This is Bruce Lee’s fighting method: lead with the strong side, and “use the longest weapon to strike the closest target.” There’s more textbook Jeet Kune Do technique here than there was in Dragon: The Bruce Lee Story.

The last fight in the movie is even richer:

I could practically call out page numbers from the Tao of Jeet Kune Do for every few seconds of this scene. The combat’s not realistic, but it’s full of real things: Boxers do get cut and bleed into their eyes. Chinese martial artists do use light attacks to open you up for heavier ones. Bruce Lee did like double and triple leads (page 198!) and disrupting opponents with that finger-flick to the eyes (Page 74!)

The scene is even better if you watch it after reading up on Jeet Kune Do principles. A lot of the stuff behind that link applies to the sword, as well — which is fitting, since Lee studied western fencing for principles to apply to his unarmed fighting. It’s about timing and psychology, rather than specific techniques.

“Remain relaxed at all times except in definite action…Strike suddenly, passing instantly from apparently total casualness & relaxation to irresistible speed & power, controlling the sword perfectly as you do.”
- Aldo Nadi

Remember that one’s striking distance is determined by the rear leg. Consider the ways towards or from your opponent:
Advance – lead leg moves forward & then the rear follows.
Retreat – rear moves back & then the lead follows.
Balestra – This is a specialized advance where one kicks out with the lead leg, utilizing a synchronized kicking out with quadricep to help propel the body forward. There is a “stomp-step” in kendo that similarly uses also utilizes a kicking motion for added range. The stomp step uses the leg to kick out like a push kick. With the lead leg, it is only superior to the balestra when stepping over kicks. However, it can be used when stepping to achieve extra range.
Walk/Step – Step forward with rear leg or back with the lead leg.
Traverse Step – Step out at a 45º angle forward and to the side.
Quartata – Step behind your lead leg with the rear, ending in a crossed-stance.
Fleché (Fr. Arrow) – Bound forward in a run with the rear leg.
Leap – Jump, keeping lead where it is.

I think it is great that, just as Americans do kendo and Asian martial arts, here we have Japanese fighting in plate-mail. Avalon an Japanese offshoot of the SCA.
The sword freeing itself from historical and ethnic boundaries will lead to a functional art (at least that’s what Mu Ryu wants).
http://avalon.tsukaeru.jp/index_en.htm/

http://www.thearma.org/spotlight/GTA/motions_and_impacts.htm
http://www.thearma.org/spotlight/GTA/motions_and_impacts2.htm
http://www.thearma.org/spotlight/GTA/motions_and_impacts3.htm

Pivot Points

Another way to think about [the harmonics of a sword] is in terms of your hand’s natural pivot point. If you strike a blow and the handle kicks into your fingers, you’ve hit out past the point that would make your hand the center of the impact. If you strike a blow and the handle kicks into your wrist, you’ve hit inside the point that would cause the weapon to pivot around your hand. By making a succession of blows, and paying attention to the kick at a particular finger, you can quickly find the desired impact point on the blade.

But the previous discussion on the pivot points of a staff showed that the distance between pivot points varies widely, growing very large as one of them approaches the center of mass. Unlike a staff, we generally grip a sword very close to the balance point. And when you grip a staff very close to the balance point, the resulting pivot point is very far away. If you grip a staff in the middle, as if you were going to throw it like a spear, it doesn’t want to rotate at all. We’ve all complained about swords that don’t swing well, because they were balanced too far back. This is the real reason why. The balance point is very close to the hand, so the corresponding pivot point is very far away, far past the sword’s tip. It is the same as trying to swing a spear while gripping it for a throw, or swinging a very long sling.

Value of Pommels

Aside from just moving the pivot point, the pommel also does some other interesting things. The pommel is very near your hand, so it doesn’t add much inertia about the center of the handle. It is on the inside of your swing, instead of near the tip, so you don’t have to accelerate it very much. However, when you make a strike near the sword’s tip, the change in the sword’s motion, pivoting near the cross, requires a significant increase in the velocity of the pommel. The impact forces are still acting through a lever, with a fulcrum located near the cross, but now with the pommel located on the other side of the fulcrum. If we leave the fulcrum’s location constant, then from the target’s perspective, the resistance to the resultant change in motion is the same whether we put the pommel eight inches behind the cross, or eight inches in front. The pommel on a straight cutting blade makes the sword hit harder, and by a very significant amount, while only making a small degradation in the sword’s maneuverability. So you’re getting the increased impact performance almost free. In short, the pommel is ingenious at many levels.

Full Tang

Once you start making hard and sharp impacts near the tip of a straight sword, some other interesting physics comes into play. The first thing you’ll notice is that your handle either bends or even breaks off. The reason this happens is again due to the pivot points of a sword. When making impacts about a third back from the tip, the impact point causes the sword to pivot around a point that was very close to the pommel. These impacts, having the change in motion centered near the pommel, don’t actually change the pommel velocity by any significant degree. The tang (the inner ‘tongue’ of the blade inside the handle) really doesn’t encounter any significant forces during these types of blows, but simply has to pivot around the pommel.

But as you start hitting near the tip, or directly on the tip, the sword pivots around the cross. This means that the pommel is far away from the pivot point, on the other side of the fulcrum, and has to make a large and sudden change in velocity. The tang is the only thing that actually delivers the forces necessary to accelerate the pommel. Since the pommel is heavy, it resists this acceleration, so the tang really has some work to do, and only a very brief amount of time to do it, because of the violent nature of an impact. In a typical high-speed impact, say 75 miles per hour, the pommel might have to change velocity by 15 mph or more, depending on hilt length. If the blade and tang are stiff, the pommel will need to change its position by ¼ inch in just one millisecond.

Blade Curvature to Cutting Quotient

Similar to some of the mistaken ideas about the draw cut are some of the thoughts on the increase in the cutting power of a slightly curved blade. Real cuts are made against extremely curved shapes, like arms and heads, and what initially matters is relative curvature. The slight difference between a section of a straight and a curved blade is overshadowed by the curve of the target. Though certainly the curved blade would be preferable in fights against square-sided people, I don’t think it matters much against round people. Once the edge has penetrated through armor and skin, the muscle should be cut quite well by either type of blade. A quick bit of testing should let us closely quantify the effects of blade curvature on high-speed impacts.

These articles are good but a bit technical. The key gleanings I have above excerpted.

He also talks some of the center of percussion and how is about a 1/3rd back from the tip. I recall thatswords tends to have their balance point at 2/3rd back from the tip. Seems like harmonics in play.