“Nimoy also introduced the Vulcan nerve pinch in an early Star Trek episode "The Enemy Within". Initially, Spock was supposed to knock out an evil Kirk in the Engineering room by striking him on the back of the head. Nimoy felt that the action was not in keeping with the nature of Spock's character, so he suggested the "pinch" as a non-violent alternative, suggesting that Vulcans have the ability to emit energy from their fingertips, which, if applied to the correct nerve cluster, could render a human unconscious. Nimoy explained this to the episode's director and, according to Nimoy, the director had no idea what he was talking about. However, Nimoy would express relief in later interviews and appearances that when he explained the concept to William Shatner, he understood it immediately (...)”