Nukite-uchi, the spearhand strike, is designed to cause permanent debilitating injuries, so it must be practiced with the utmost care and attention. For this reason, it is forbidden to use spearhands during kumite. Spearhand strikes are thrown just like a front-foot or reverse punch, but impact is made with the fingertips instead of the seiken.
Goshin-Jutsu uses two variations of spearhand strikes: two-fingered, and four-fingered.
Two-fingered spearhand strike
Nihon-nukite uchi, the two-fingered spearhand strike, has only two applications -- to pierce the eyes or throat of your opponent. Two-fingered spearhand strikes are often performed with the lead hand as an atemi.
[Photo of a nihon nukite]
[video of a nihon nukie from the front and the side]
Some Goshin-Jutsu kata and waza use a "Three Stooges" variant of nihon-nukite uchi to strike the eyes. Other karateka refer to this technique as hebiken-uchi, or snake-fist strike, since it resembles a snake's fangs. Goshin-Jutsu differs from other karate styles by performing these "Three Stooges" strikes with the palm facing upward, to prevent the fingers from buckling on impact.
[Photo of a stooge nihon nukite]
Four-finger spearhand strike
Yohon-nukite uchi, the four-fingered spearhand strike, is more robust and is used to attack soft tissues, such as the opponent's throat, solar plexus, abdomen, bladder, or armpits. Four-fingered spearhand strikes are often performed with the reverse hand to maximize power.
[Photo of a yohon nukite] [video of a yohon nukie from the front and the side]