Can you knock someone out with pressure points, in the style of a Vulcan nerve pinch?

Question

Is it possible to pinch someone's nerve (on the shoulder) in a manner similar to the way Spock would do on Star Trek such that the person would either pass-out or result in being temporarily paralyzed?

Proponents of Ryukyu Kempo martial arts claim it is possible:

• Does the vulcan nerve pinch have any real counterparts?

Yes. If you were to study the art of Ryukyu-Kempo, you would discover that the body is full of pressure points that can be exploited to immobilize, knock-out and even kill a person. There are two points that correspond to the position of the fingers in the nerve pinch.

Since I do not understand this style of martial arts I can't determine if it's actually possible.

Answer 1

Evidence:

1. The touch of death is known in Cantonese as Dim Mak and in Japanese as Kyusho Jitsu. Traditional Chinese medicine claims that chi or energy flows through the body along lines called meridians. A study published online by the British Medical Journal found that Acupressure (applying pressure with the thumbs or fingertips to the same points on the body stimulated in acupuncture) seems to be more effective in reducing low back pain than physical therapy.

The related claim that placing pressure on these meridian points might bring about better balance, circulation of fluids like blood and lymph, and metabolic energies in the body has little to no scientific evidence. It is also further claimed that a blow or squeeze applied to certain other pressure points on these lines will influence the victim's chi, leading to incapacitation or death.

2. Per Ter­ry C et.al.'s research in 1999, unre­spon­sive­ness ­have ­been ­observed due to pres­sure ­point tech­nique application in vol­un­teers performing mar­tial ­arts dem­on­stra­tion car­ried out at a med­i­cal cen­ter hos­pi­tal. The results of that study of kyusho jitsu pres­sure ­point tech­niques used in mar­tial arts showed that there was no change in BP, cardiac rate or rhythm.

Conclusions: The ­exact mech­a­nism for the ­state of unre­spon­sive­ness pro­duced by appli­ca­tion of pres­sure ­point tech­niques is uncertain. There is no evi­dence of ­reduced cere­bral ­blood ­flow or of oth­er dan­ger­ous phys­io­log­ic chang­es and it is not relat­ed to a sig­nif­i­cant car­diac or pul­mo­nary pro­cess. Source: Physiologic study of pressure point techniques used in the martial arts

TL;DR: The touch of death has no basis in reality, however, there has been occasional instances of less forceful blows causing death and the exact mechanism causing this phenomenon is unknown to science at the moment.

Having browsed the medical literature, I'd say the verdict on whether this mysterious Oriental skill has any basis in reality is as follows: The touch of death, no. The less forceful blow than you might expect of death, occasionally yes. Source: Straight dope