A pressure point (Japanese: kyūsho 急所 "vital point, tender spot"; Chinese: 穴位; Malayalam marmam) in the field of martial arts refers to an area on the human body that may produce significant pain or other effects when manipulated in a specific manner. Techniques of attacks on pressure points are called Hyol Do Bup (Hangul: 혈도법; 穴道法) in Korean martial arts and kyūsho-jutsu (Japanese: きゅうしょじゅつ) in various styles of Japanese martial arts.
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).
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 Trekkies as the "Vulcan nerve pinch."
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.
Blood and blood pressure
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. Thus, striking this area can cause unconsciousness, both using the same mechanism and relying on the force being transmitted to the reticular activating system.
There are certain areas which are likely to lead to a break if struck properly, 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. 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, them the elbow can be broken with significantly less effort than it could through brute force.
The brain is a sensitive organ which floats in a fluid (cerebrospinal fluid). The fluid itself is a safety mechanism that allows the head to take substantial impact without resulting in concussion, although such an impact could still cause permanent brain damage. However, it is possible to deliver a blow using artful techniques in such a way that even these protections can be effectively eliminated, causing disorientation or instantaneous knockout. The most commonly taught technique involves a strike just below the occipital ridge, at the correct angle, in the correct direction. Another well-known point with this effect is the chin or lower jaw, giving rise to the boxing expression a "glass jaw". The same effect of knocking somebody unconscious may be achieved by using the edge of the hand, palm-up, to apply a sharp strike to the carotid artery.
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 pseudosciences 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. However, despite many attempts using placebo-controlled doubled-blinded experiments to find these points, these so-called meridians have never been located or proven scientifically, pointing to the conclusion that they may not exist at all.