The first punch taught in the Sodokan dojos is the, 'Straight Punch', (Choku Tsuki). It is a fundamental technique and commonly referred to as one of the 'Basics'. This may infer that it is simple and without complexity, this is not so, even this first level punch is difficult to do correctly.

The straight punch, contains principles that must be thoroughly researched and practised. The straight punch is not merely throwing out the arm out as hard and fast as possible. Performed correctly it is a stepping stone to the higher levels of striking.

Start by forming the fist, folding first the little finger and then the ring finger. Continue with the middle and index finger. The thumb then folds over the index and middle fingers. Make the little and ring finger firm by moderately squeezing. At this stage the remaining fingers are held lightly folded. This is similar to the grip of the lower hand on the handle of a sword in Budo.

Draw the arm back to the ready position beside the chest. It is important to relax the shoulder and allow it to drop down, as tension in the shoulder makes the punch stiff. This is difficult as the majority of people maintain tension here without realizing. The back muscles should be firmly contracted. This pulls the shoulder down and 'connects', the arm to the trunk of the body.

The fist in the 'Naha' styles are held at chest height in line with the nipples i.e. Goju Ryu, Uechi Ryu. This has several benefits. As the punch extends, the technique begins naturally with middle block, so is able to intercept a punch in the same motion. Hence a punch is a block and a block is a punch.

Additionally holding the fist higher than the elbow enables better body mechanics to generate a stronger drive outwards

In the Shuri styles i.e. Matsubyashi Ryu, Shotokan, Wado Ryu etc., the fist is held at waist height, this has the benefit of assisting the shoulder to drop more easily.

Drawing the fist back to side of the the chest, angles the forearm so that a straight line from the knuckles to the elbow points down to the ground behind. There should be a feeling of pulling down and back, (not just back), with the elbow. This is important as it keeps the shoulder 'connected', and the forearm is maintained at the correct angle.

The elbow should NOT stick out. It should at the very least be in line behind the fist, so that the line of force points straight ahead. To assist the correct elbow positioning, the forearm is rotated outwards so that the elbow is pulled in. As a check the first two knuckles are held level and perpendicular to the ground.

Importantly, press the area of the forearm below the wrist against the chest. Don't press the edge of the fist against the ribs otherwise the elbow will stick out.

By combining the press of the forearm against the chest and rotating outwards this will position the elbow slightly behind the shoulder blade at its optimum position. The line of force should travel from the tip of the elbow through the knuckle of the little finger.

Do not tightly squeeze the thumb and index fingers yet as this feeling will tense the bicep muscle. This will then have the effect of holding the punch back, much like trying to drive away with the brakes still on. Instead squeeze the ring and little fingers and press the shoulder and elbow down and contract the Triceps. As the Triceps is used to extend the arm, contracting this muscle is like drawing a bow.

The ' unbendable arm' used in some schools is said to demonstrate the extension of Ki energy. Extending a relaxed arm laid over a partners shoulder palm up, the partner tries to bend the arm at the elbow - unsuccessfully. The Bicep remaining relaxed throughout if offered as proof of Ki extension. However the Triceps if felt is tensed as this is the extensor muscle group and not the Biceps.

Just before the punch starts to travel there is a sense of pulling with the crook of arm. This feeling can be developed by working with a partner who stands behind and holds either side of the elbow with the palms to provide a moderate resistance. As the pulling action overcomes the restraining resistance this causes the arm to suddenly accelerate outwards. With practise this resistance can be applied internally creating the acceleration.

It is important that the forearm stays in contact with the side of the chest as it travels and does not start to rotate until the elbow has passed the side of the chest. Otherwise too early a rotation of the forearm will cause the line of force to be directed away from the target and weaken the punch.

At the point of contact the arm is not yet fully extended so that there is still a slight bend in the elbow. If the punch lands with the arm already fully straightened then there will be reduced penetration into the target area. The elbow does not stick out to the side otherwise the arm is liable to bend on impact, it should point down and remain in line with the shoulder, fist and target. This is referred to in the Sodokan dojo as ' the line of force'.

The fist impacts with the first two knuckles slopping at an angle of 45 degrees, with the index knuckle higher than the second knuckle. In the moment prior to contact all fingers of the fist are squeezed to create a strong unit including the wrist. As the fist penetrates, the forearm rotates through 90 degrees, performing a quarter turn. At the fullest extension the fist again slopes at 45 degrees, but this time the second knuckle is higher than the index knuckle.

As the fist rotates through 90 degrees the shoulder is allowed to roll and extend forwards adding to the force of the punch. The shoulder must not be allowed to lift as the shortens and weakens the technique.

At the point of maximum extension the tight grip on the thumb, first and second finger is released in addition to the shoulder relaxing and rolling back. . As this happens the forearm rotates back through 45 degrees so that this time the knuckles are both level. This pulls the arm back slightly so enabling a further short jab to be used at very close range.