Vertical punch

The Isshin-ryū punch is launched from the side, keeping the fist vertical the entire time.(A still picture of Master Shimabuku striking the makiwara shows the fist rotating a quarter turn.) The elbow is kept close to the side and the shoulder is relaxed and dropped. The punch is usually practiced targeted at the solar plexus, not higher at the face or head. The punch strikes with the first two knuckles of the hand and then snapped back - much like cracking a whip. At the completion of the punch the hand and arm are left in a position ready to punch or block again immediately with no wind up. Care should be taken in practice and application to prevent the elbow from becoming injured by keeping the joint somewhat bent upon delivery. This is especially important when practicing without actually striking an object. Punches in this style are not usually long ranged. If the elbow was not bent upon contact the target was too far out. When timed it is possible to land three of these punches in the time it takes to land two corkscrew punches. This punch is not only faster, but more powerful than a twisting punch; We are moving the same mass as a twisting punch does, but with much more speed.

Beginning at the fist and moving up the arm: The fist is made by holding the hand open and then slowly curling the fingers from the most distal knuckle until a fist tight enough to completely hide the fingernails is made. Then the thumb is pressed down on the second knuckle of the index finger. Styles which practice a twisting punch frequently wrap their thumb down over the fingers, which begins the arm torque they use for their punch and this is precisely how Shimabuku taught it when he taught a twisting punch. Since Isshin-ryū punches straight ahead, the vertical thumb position allows for cleaner alignment of the wrist and arm bones.(A still picture of Master Shimabuku posed with his students shows the thumb not standing straight up, but rather laid over, touching the "web" of the hand. This position supports and protects the thumb, while maintaining the advantage mentioned above.) This position of the thumb also allows for it to be used as a specialty weapon for precision striking, or Atemi, at delicate and vulnerable targets such as the temple or other nerve shots.

The fist is held straight, lining up the bones behind the first two knuckles to distribute the impact to both the radius and ulna. The arm is relaxed, with the elbow and shoulder both tending down toward the ground.

The Isshin-ryū vertical punch appears to owe as much to the vertical punch practiced by the older Chinese form of Hsing-I as it does to its direct lineage in Okinawa-te. It is also believed that Shimabuku used the vertical punch in an attempt to distinguish his style from other styles prevalent at the time. While this view is not widely held, it is nevertheless one theory that has been proposed that has merit. The body structures used in the strike are especially strong at close range and toward the center of the body, providing a different set of optimal striking distances and postures from the more common twist punch practiced by other styles.

While Isshin-ryū did indeed utilize a vertical punch during Shimabuku's last years, he switched several times between teaching the vertical and twist punch, however, he kept certain elements constant between them. For example, the snapping, whip-like movement was common and was done in order to create a maximum transfer of energy from the hand to the opponent. It was explained that by leaving the hand in contact with the opponent the energy would send a shock wave through the opponent, which would reflect backward and travel back into your hand and arm should contact be maintained. He also explained that twist punches were often more devastating.