The touch of death is any martial arts technique reputed to kill using seemingly less than lethal force targeted at specific areas of the body. The concept known as dim mak , alternatively diǎnxué traces its history to traditional Chinese medicine acupuncture. Tales of its use are often found in the Wuxia genre of Chinese martial arts fiction. Dim mak is depicted as a secret body of knowledge with techniques that attack pressure points and meridians, said to incapacitate or sometimes cause immediate or even delayed death to an opponent. Little scientific or historical evidence exists for a martial arts "touch of death"; however, in rare cases, death can occur in response to trauma such as commotio cordis, an often lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart. The concept known as vibrating palm originates with the Chinese martial arts Neijin energy techniques that deal with the qi energy and the type of force used: "a technique that is part psychic and part vibratory, this energy is then focused into a wave".