V'asumi was a martial art practiced by the Vulcans. It emphasized the use of speed and skill.
The duo-katas of V'asumi were an exercise and an art form based on the simulation of combat. This meant that they were fatally fast and potentially lethal, with several terminal maneuvers which required a sparring partner to not miss the beat in the reading of their opponent moves or in demonstrating a blow millimeters short of a deadly impact. When done perfectly, the control during the moves made it appear as an ancient dance of sworn warrior brothers. The locking of the wrists of the right arm was a sign of a warrior's acknowledgement to each other, after which they stepped back to bow. During such combat, it seemed that the desert and the le-matya lived there.
The green sash that one earned from V'asumi was only a Vulcan child's earning which was typically earned before the kahs-wan trials at the age of seven. This martial art was known to restrain strength but not power. The practice was not similar to K'asumi, with the difference in strength between opponents being ineradicable. Some felt that the difference was no excuse for acceptance of a less than full potential, which meant that lowering one's level to another's was considered an outrage. The T'hyvaj was a mirroring exercise, a part of the asumi martial art which was not taught to other species as it was from the ancient path of warriors, from T'hy'la before the modern days.
In the 23rd century, Spock taught several members of the USS Enterprise crew the V'asumi art. By 2274, James T. Kirk had obtained a green sash in the martial art. When Admiral Savaj learned of this, he requested a demonstration of the crew's performance in the martial art exercise. Afterwards, Savaj scolded Spock for reducing his potential in order to allow Kirk to fight. (TOS novel: The Prometheus Design)