Can finger nerve damage cause blindness?

One of my friends says that his Kung Fu teacher said that trying to break boards in the wrong way can cause nerve damage in the hands, and that this nerve damage can cause blindness of the eyes, through some kind of neural connection between them, or something.

This sounds really suspicious. Any comments?

D’oh! I forgot to add that he said that ANY kind of nerve damage of the fingers causes this. But, for some reason, that having your entire finger blown off will not cause blindness.

Well, maybe if the finger nerve damage was caused by excessive masturbation. :smiley:

I can say that I have finger nerve damage in two fingers (from a deep knife wound), and I haven’t gone blind yet.

Sounds very dubious to me. As is martial art board chopping. The boards used are specially cut so as to practically fall apart on any contact.

See James Randi’s examination of this: http://www.randi.org/jr/08-10-01.html.

So I suppose that breaking boards in the ‘wrong way’ can damage your hands. But why this should do anything to your sight is beyond me. It’s probably just a tale they tell to stop them trying it at home.

Your link didn’t work. I’ve seen people break boards and they are not cut or prepared in anyway beforehand. This isn’t rocket science, breaking boards is pretty easy.

Looks like the board’s software tacked a period onto the URL.

Try http://www.randi.org/jr/08-10-01.html

Uh, so is that why when testing for belts in Tae Kwon Do, I’ve watched classmates break toes, tear open thier hands, and various other injuries?

The worst ever happen to me was severe brusing when the board didn’t break on one knife hand break and one spin hook kick break.

Stick with what you know. The boards we tested with were in no way scored to facilitate breaking.

Perhaps his Kung Fu instructor is an alien from the planet Krypton or somewhere, where they have eyes in their hands.

I don’t know about breaking wind, though. Perhaps if you break wind strong enough, you can cause some eye damage? Well, yeah, someone is likely to punch you in the eye.:smiley:

Nerve damage causes twitching, person attempts to rub eyes, twitch occurs, and person pokes out their own eye!!!

Use this method to impress your friends and amaze your enemies:

Purchase a 6 foot 1 x 12 pine board.

Cut said board to 6 inch lengths.

Chop away! It’s easy!

Why is it easy? the grain of the small boards you created is perpindicular to the length of the board. Breaking a board of continious grain is very difficult. Breaking a board that has had all the grain cut is easy. The strength of wood lies in the grain.

If you’d take the time to read the link supplied … Sorry about the rogue dot that got in there previously.

The boards are easy to break because the wood has been cut into lengths against, rather than with, the grain. This means grain runs across the board and not along it. No additional cutting or scoring required.

I don’t know if this wood would still be tough enough to hurt your hand. I suppose you’d have to be careful of where the knots were. But it is still very much easier to break than the lengths of wood you’d normally encounter. No timber-merchant would choose to cut wood in this way, as the resulting boards are totally useless for any kind of construction.

So, to get back to the OP, the instructor was spinning a line to stop his pupils going home and trying it out. Any wood they might have lying around at home is practically guaranteed to have been cut the correct way and be nearly impossible to chop with your hand. The fact he didn’t just own up to this, making up some nonsense instead, gives credence to Randi’s opinion that the whole ‘chopping wood’ thing is a bit of a cheap party trick.

This doesn’t mean that everything else these guys can do is a fraud or that the martial art in question has no merit. I wouldn’t want anyone deciding to come around and give me a practical demonstration! :smiley:

Huh? What does that mean? Does that mean the grains are running in what direction? X, Y, or Z (thickness)?

Put it another way. If you put a wooden board flat on a surface so that the Z axis is perpendicular to the surface, will the grains lie parallel to the surface, or perpendicular to it?

Right now, for the surface of my desk, the grains are running up-down. Or perpendicular to the surface in the situation above.

A diagram.

Length of wood cut normally for maximum strength:

|-------------------------<O>-----------------------------------||
|--------------------------------------------------------<o>----||

Length of wood cut so as to easily snap:

||||||||||||||||||||||||||(O)|||||||||||||||||||||||||||||||||||||
||||||||||||||||||||||||||\v/|||||||||||||||||||||||||||^|||||||||

The optic nerve is a cranial nerve–direct link to the brain, doesn’t go through the spinal column. (I’m pretty sure that’s also true of every nerve having anything to do with the operation of the eyes/eyelids/etc.) The notion that a hand injury can affect one’s sight strikes me as patently ridiculous.

Hm. The thing is wood grains are concentric circles (more or less) . Unless you are talking about really, really big trees there really isn’t a whole lot of choice how wood blocks are sliced. In other words, there isn’t much against or with the grain per se.

Anyway, even if I cede the point of them using trickery with wooden planks, what about bricks?

Have a look at a piece of wood sometime. Wood is cut for strength as described above, with the grain running the length of the board. The way grain runs is everything in wood. It gives it strength, it gives it tone and flexibility when used on musical instruments.

Did you read the link?

Yes, many claims of breaking multiple blocks of ice with seemingly superhuman strength and such is quite far fetched to say the least. Same goes for the wooden boards – they ARE easier to break because of the grain–however, it isn’t easy to break multiple boards…say 4~5. I’ve seen people break red bricks too, totally insane considering I couldnt even get one to split down the middle with a hammer.