The basic difference between the Japanese and the Korean long sword is that the katana possesses a slight arch. The jung kum, on the other hand, is oftentimes straight. The use of the jung kum is not universal in Kumdo, however, and the Japanese katana oftentimes replaces it.
The straight design of the jung kum was brought into utilization predominately by the Korean systems of Kuk Sul Won and Hwa Rang Do. Both of these systems possess a more Chinese influenced art of swordplay than does Kumdo. Though the straight sword is now commonly associated with the Korean arts, in the Moo Yeh Do Bok Tong Gi, the long swords are detailed as possessing the same arch as those used by the Japanese Samurai.
The "Tanjun," more commonly known by the Japanese term, "Hara," is understood to be an individual's center of gravity. This bodily location exists approximately four inches below the navel.
In Kumdo, it is understood that all sword techniques must be launched with a consciousness placed on this bodily location or the practitioner will easily be set off balance by his sword. From a more metaphysical perspective the tanjun is also understood to be the location where ki, "Internal energy" congregates. Thus, this location is quite revered.
Human breath is known to be the link to ki. Thus, a Kumdo practitioner always breathes in ki and mentally directs it to his tanjun at the outset of each sword movement. When the sword is unleashed, this ki filled breath is released with a, "Kiap," a martial arts yell. This signals that ki is being expelled as the sword moves towards its target.
Holding the Sword
In Kumdo, the sword is held with your lead hand placed just under the sword guard. In some designs the jung kum possesses no sword guard. In these cases, your lead is placed in the same location, at the upper region of the sword's handle. Your rear hand is located at the bottom of the sword's handle. From this grasp, maximum control is maintained over the sword.
In certain Kumdo techniques, the sword is wielded with one hand. In this case, the hand holding the sword remains close under the sword guard. Thus, maintaining maximum balance and control over the sword.
When the jung kum is held, your elbows should remain slightly bent. This is true in all Kumdo drawing, ready position, and striking techniques. From this, you allow your arms to remain loose. Thus, possessing the ability to readily direct or redirect your sword technique with speed and accuracy.
Drawing the Sword
In Kumdo, as with Iaido, the primary focusing technique witnesses the practitioner precisely draw the sword and unleash a highly defined striking technique. In Kumdo, once the sword has been unsheathed, these defined strikes often times include the use of the sheath as a blocking tool. This use of the sheath, as a defensive weapon, is one of the factors, which separates Kumdo from most schools of Iaido.
Eight Primary Strikes
All techniques used in Kumdo are based in eight primary strikes:
1) Overhead Strike, Straight
2) Overhead Slash, Left Side
3) Overhead Slash, Right Side
4) Side Slash, from the left
5) Side Slash, from the right
6) Under Slash, from the left
7) Under Slash, from the right
8) Under Body Strike
Variations are added to these techniques as the Kumdo practitioner becomes more advanced with his use of the sword.
In Kumdo the strike of the sword is never over extended. The practitioner must always control the blade as opposed to being controlled by its weight and momentum. This is accomplished by never randomly striking at the imaginary targets. All strikes are performed consciously with precise impact points in mind.
The development of proper sword strike ability is achieved through conscious practice and proper technique. A sword, in practice, is always extended with the same intent or controlled force that would be used in a true confrontational situation. It is a misnomer that a sword is wielded with a different intensity when one is defending against an imaginary opponent or a real object.
Understanding The Kumdo Sword Strike
Kumdo sword strikes are made in linear fashion. That is to say, they are performed in a straight to the target pattern. Whenever a strike is performed with the sword, it is quickly and precisely snapped into its final position. The sword techniques are not ornamented or flashy. And, no unnecessary energy is used when they are performed. This is where Kumdo differs from some of the Chinese schools of swordplay.
As is the same with the kicking and punching techniques indigenous to Korea, all sword strikes are not ended at the beginning of the target. They are, instead, performed in an application that would penetrate and go through said target. This implementation does not negate the previously mentioned conscious impact point. What it does entail is that the Kumdo swordsmen learns how much impact must be delivered in each sword application to penetrate their intended target.
All Kumdo sword strikes are precisely implemented movements. Through continued practice the swordsman comes to the understand how each sword technique is most efficiently performed. This is accomplished by observing how much force is used in each sword technique, where that energy is most effectively focused, and how much power it will take to achieve the desired result. All of this come from continued practice and developed understanding.
Scott Shaw (2000). Kumdo The Korean Art of the Sword. On-line. Available: http://www.scottshaw.com