bignick said:
I really didn't want this to turn into a discussion on the application of the technique...but i have to again disagree...the human hand can take unbelievable amounts of punishment...try throwing a punch at a hard target without proper form or making an improper fist...you'll do just as much damage as a spearhadn gone bad...if your wrist is bent you could break it...ever done a knifehand break...how many boards...bricks...the most i've tried is four boards it was pretty easy...that's a lot of force on the hand...from a different angle yes...but still lot of force...although...a palm strike is very stable i must admit...
There are several ways to strengthen your fingers for nukite. The first is doing your shuto and nukite with proper form. Extending the fingers as far out as they will go, and keeping them splinted against one another. For the knifehand the fingers, thumb included, should be straight. For nukite all fingers are tight and straight too, but the thumb is tucked in. If you have access to cane or bamboo, you can make a bamboo bundle, by getting a bunch of cane together in a bundle, and tying off the ends with strong rope. Next you place it in a container that is rooted to the ground. You practice your nukite by thrusting it straight in and out of the bamboo bundle.
The advanced tech is something out of a Run-Run Shaw flick, but it is a real training device. Get a five gallon bucket and fill it with coarse sand. Practice thrusting your spearhand in and out of the sand until this becomes really easy and your fingers don't bend. Next move up to something bigger, like corn. Using corn actually toughens your tendons/hands and softens your skin. When you can do this with ease, then move on to the gravel bucket. That's as high as you need to go. No need for giant jagged stones or whatnot.
If you can get access to Okinawan chi-ishi or Chinese single-end concrete weights, or to earthen jars filled with sand, you can strengthen your fingers and hands using these old school tools.
The most important modern tool you can use to strengthen your fist and openhand strikes is the heavybag. When you practice your knifehand on a heavybag you will have little problem. However, the nukite is different. In order to keep from jamming your fingers you need to learn to make other hand forms like Matsumura's Nukite, and the Pitchfork hand. That comes later.
Don't listen to what those other guys are saying. If you practice anything in moderation and the smart way it won't cause you any damage. In fact it'll make your hands stronger than you ever thought possible. Just be smart and moderate with your training, and after a couple of years of proper training your hand techs will surpass your TKD kicking acumen
. Remeber extend your fingers to the sky and train good Qigong when you do forms. That is the most overlooked aspect of modern karate training. Hope I helped. Later...