The hands are used basically in two ways, either open or is a fist.  To make a proper Isshinryu fist, first curl fingers tightly from the second joint to the base of the fingers.  The tips of the fingers should just touch the callous pads of the palm.  Bend and clinch fingers from the knuckles and squeeze the palm of the hand with the fingertips. The back of the hand and in the first joints of the fingers should be in a 90-degree band.  The top of the thumb should be placed in the crease made in the first finger joint and then flattened down as much as possible on the top of the hand.  In Isshinryu, the thumbs are not down along the sides of the fingers, but are up on the top of the hand.  When the fist is properly and firmly made it will feel as if a role of pennies is held tightly in the hand.  The fist, when viewed from the back, has a very definite wage shape appearance. 

Seiken (fore fist)  
The fore fist punch it is the most frequently used punch.  Contact is made with the first two knuckles only.  If any other knuckle strikes, the punch is improperly executed.  In order to maintain maximum power for this thrust, an imaginary line is drawn from the center of the forearm down the wrist and out between the first to knuckles.  This line must not be bent.  If the wrist is moved up or down, left or right, the punch will be weakened and the wrist possibly injured.  When the fist is properly and firmly made, you will be able to see an indentation in the top of the wrist just back of the base of the thumb.

Pretend that there is only one bone in your arm from the elbow to the knuckles.  If there is one solid bone, it cannot be bent.  If it does not bend, you will not lose power.  This thought must be in your mind at all times when learning the proper use of Seiken.

   
Uraken (back fist)  
The fist is made the same as for Seiken.  The striking point is almost the same,                                                         but more to the upper and back part of the fist.  When this technique is used, the fore arm and the wrist are kept stiff and the elbow flexible.  The blow is made by using the snapping motion when the fist is swung from the elbow, vertically or horizontally.
Uraken is used to attack the face, head and sides and center of the chest.  The groin can also be a target from a Uraken swung horizontally.
 

Tetsui (hammer fist)
As the name implies, the fist is used like a hammer, striking with the little finger side of the fist.  As in Seiken, the wrist does not bend and the snapping motion comes from the elbow being used in a whip like manner.

Tetsui is a very powerful blow and is used against the head, neck, sides of chest, etc.

Shuto (knife hand)
The little finger side of the open hand is used for striking.  As the name indicates, the knife hand is used in a chopping or cutting fashion.  Once again, the wrist is held solidly, the hand tense and the thumb pressed down along the edge of the hand or folded slightly into the palm of the hand.  The hand thus can attack almost all parts of the body – particularly the neck.

Haito (ridge hand)
Similar to shuto except the thumb side of the hand is used for the strike.  With palm up it is used for very strong chest blocks.  With palm down, very effective for strike to the neck and sides of the head, etc.

Haisu (back hand)

In this technique the back of the open hand is used.  The hand is held rigidly open.  Although used mainly for blocking, it is quite effective against the chest and face.

Nukite (spear hand)
This is a forward thrusting made with the tips of the fingers.  The fingers are bent slightly inward and are tensed.  With Nukite, one can attack the eyes, throat, solar plexus, under the ribs and groin.  A very good target for Nukite is the exposed arm pit.

Shotei (palm heel)
By bending the wrist upward and pulling the fingers back the heel of the palm is exposed and tensed.  This is then used in attacking the face, nose, jaw and solar plexus.  A very strong technique, it is effective in deflecting or blocking kicks and punches.  Normally used striking upward, it is also effective against the groin by turning the palm up.

Kakuto (bent wrist)
Bending the wrist downward and then using the back of the wrist for the strike do this.  Very good for upward blocking and side strikes in the head or chest.

Empi (elbow)
The point of the elbow may be used by swinging it upward, downward, backward or to the sides.  Very effective for close in fighting and can be used to attacking the chin, chest, solar plexus and the ribs.  Very good technique for women who are usually not as strong as their opponent.

"There are many more!"