Could cord-cut be a real martial arts technique?

Question

This is a technique from the anime Baki the grappler, which can be checked here.

The "Cord-Cut" name refers to the countless "cords" that makes human body. The cords includes blood vessels, lymph ducts, tendons and nerves. To use that technique, the fighter have to train his fingers to the limit. Then he need to study a lots about the human body. When the training is completed, the fighter can sever the opponent's cords with a finger.

I've my doubts if that technique would be possible in real life, and if so, to what extent.

For my story, the user of that technique is free to have their nails as he wishes, he can train his finger and general strength as much as he wants, and he can even use special products for having harder nails.

I don't count for this technique something as rupturing a capillary, that's a no brainer, but something like severing an arterie, a vein, a lymph duct, a nerve or a tendon, being severed by the action of the fingers of the trained person.

Would such a thing be a real possibility?

Answer 1

There are two major limits to this technique which you would need to overcome.

The first is that evolution is not dumb. Well, it is dumb, as in it has no goals, but it has done a very good job of making a body structure which keeps you alive. There are only a small number of places where there are key unguarded "cords." Typically the arteries are deeply buried. Even veins are reasonably protected If you ever wonder why angioplasty, a heart surgery, goes in through the groin, it's because the femoral artery is unusually accessible at that point. You only have to push around a few layers of muscle to get access to it. Thus you would need your martial artist to have the skill and strength to cut all the way to the cord before cutting it.

There are a handful of tendons that might be easy targets. The Achilles tendon appears in some sword martial arts as a weak point, if you can find a chance to strike such a small target meaningfully. Also the tendons in the wrist and the back of the knee are rather exposed.

The other issue is that cutting a cord actually calls for cooperation on the part of the opponent. Try this: get a length of string and a pair of scissors. Hold the string up on one side and try to cut the string below it. It's nearly impossible unless you have some good sewing scissors. You need tension on the string to really cut it. Otherwise it gets out of the way. Now repeat this process with a knife, rather than scissors. It's even harder because we don't have two opposing pieces of metal. You're trying to do this with a finger: go get an ice pick and try to cut that string!

Fortunately, opponents will often tense such cords for you. If there is stress, there are tense cords. Part of your technique would need to be convincing your opponent to fight you in positions of poor mechanical advantage. Offer a "vulnerability" for them to strike. All they have to do is over power you. However, in the process of overpowering you, they'll tense their cords, and you'll have something to attack.

If you look at the best martial artists around, you'll find that they don't leave cords tense for a long period of time. Doing so is very wasteful from an energy management perspective. Only the weak martial artists make the mistake of leaving things tense longer than they have to. Even in sports like boxing and MMA, which don't have the word "art" in their title show this skill, so you'd find it very difficult to take on a skilled fighter, whether they practiced a "martial art" or a "fighting sport."

Answer 2

Why settle for one finger when you can have five?

Check this out: Tiger Style Kung fu (source National Geographic)

In the video, the martial art practitioner manage to rip the throat out of an anatomical dummy made of ballistic gel (about the same pierce resistance as human flesh), stopping just short of the neck vertebrates. This is about the best simulation that is not trying the move on a person here.

Remember though, this technique require lots of practice (so much that the bones of the fingertips suffer microfractures, which then heal solid), the martial artist is on stable ground, land a solid hit, and the dummy is not defending itself or fighting back. So I will say this is plausible, but rather situational.

In addition, whoever doing this must be able to hit the enemy's vital blood vessels, lymph ducts, tendons and nerves (i.e. small, moving targets) during a highly stressful situation as well. Or don't, I know I would run if someone who can literally hand me my butt want to fight.

So brush the dust off your Physiology notes, learn Tiger style Kung fu, and find a reason as to why you want to shove your fingers into people, and one day you might do it too.

Answer 3

Many martial arts were developed because the shogun or emperor prohibited his subjects from keeping weapons, so a practitioner would basically break his hand, arm, and leg bones again and again until they regrow into extremely hard weapons. In a fantasy world that doesn't rip off medieval Japan, are bits of metal, glass, or obsidian so difficult to find that hardening one's bones is the only way to defend oneself? What if the opponent were wearing shin guards or body armor? Why spend years of pain to learn to cut an opponent's tendons bare-handed when a pair of scissors would do the trick? Other types of martial arts such as jiu-jitsu, Krav Maga, or MMA seem more useful because the practitioner trains for realistic situations where knocking down the opponent rather than ripping out his throat is the primary goal.

Answer 4

This may not be quite what you’re looking for, but some martial arts techniques involve hitting nerves where they’re near the surface (typically near joints). Whilst it doesn’t cause permanent damage or “cut” them, it can affect the nerves temporarily, at least for a few minutes.

A sensei I trained under would sometimes show this technique; it left my arm numb and somewhat unresponsive - not completely paralysed, but unusable for a fight. I don’t know how long the effect would have lasted as he undid it with a quick massage (he was also a shiatsu massage practitioner; I believe the points he attacked were from the massage technique).

The explanation given for this was all in terms of “chi”, but a medic I talked to confirmed there were clusters of nerves in the points he hit, and that an impact to them would have the effect I suffered.