The concept of pressure points is present in old school (17th century) Japanese martial arts and is claimed to have an even earlier history; in a 1942 article in the Shin Budo magazine, Takuma Hisa Sensei asserted the existence of a tradition attributing the first development of pressure-point attacks to Shinra Saburō Minamoto no Yoshimitsu (1045–1127). Hancock and Higashi (1905) published a book which pointed out a number of vital points in Japanese martial arts. Exaggerated accounts of pressure-point fighting appeared in Chinese Wuxia fiction and became known by the name of Dim Mak, or "Death Touch", in western popular culture in the 1960s. One of the best-known uses of pressure-point fighting is known to Star Trek as the "Vulcan nerve pinch", and is also seen in the animated Avatar: The Last Airbender series, when female antagonist assailant Ty Lee disables Katara's telekinetic "waterbending" skill with "chi-blocking" pressure point attacks. While it is undisputed that there are sensitive points on the human body where even comparatively weak pressure may induce significant pain or serious injury, the association of kyūsho with esotericist notions of qi, acupuncture, or reflexology is controversial.
There are several types of pressure points - each is applied differently and each creates a different effect. "Pain points", for example, use tendons, ligaments, and muscles - the goal is to temporarily immobilize the target, or, at the very least, to distract them. Reflex points produce involuntary movements; for example, causing the hand to release its grip, the knees to buckle, the target to gag, or even for the person to be knocked unconscious. Most pressure points are located on pathways on the nervous system.
Some pressure points produce pain when struck, pressed, or rubbed, depending on the point itself. These points are also referred to as nerve centers. While the distraction of pain might offer sufficient advantage in a fight or escape, the body also has a pain withdrawal reflex, whereby it reacts to pain by moving away from the source. Martial artists can make use of this reflex with minimal effort. The baroreceptors in the carotid artery are pressure-sensitive, supplying the brain with information to control systemic blood pressure. Pressure against this region will send signals that indicate that blood pressure is too high, leading to a lowering of blood pressure. There are certain areas which are likely to lead to a break if struck effectively, such as the "floating ribs", the philtrum, and the side of the knee.
There are joints that, when struck, can be hyper-extended and even tear. The striking of these joints is a technique which can cause permanent damage to one's opponent as well as cause shock damage. There are two types, as follows :
- Brute force, which, when applied, takes advantage of the vulnerability of the strike point, usually a joint, thereby causing damage.
- Golgi organ strike, a relatively gentle strike to the Golgi tendon at the back of the elbow, which triggers a reflex that immediately relaxes the tendon, allowing the elbow to bend more easily in the wrong direction. If this is directly followed by a solid strike to the elbow joint, then the elbow can be broken with significantly less effort than it could through brute force.
Some fighter artists believe that there are energy channels (acupuncture meridians) which allow Qi, or "life-force", to flow through the body. Acupuncture, for example, is well-known among the practices that use the meridian system. Traditional Chinese medicine practices in general are largely based on the belief that meridians are specific pathway lines in the human body, along which are found many hundreds of acupressure points. According to this belief, attacks can be used to impact the flow of Qi, and, thus, the body. Therefore, pressing, seizing, or striking these points with specific intent and at certain angles is believed to cause either a heightening or a diminishing of Qi circulation in the body.