In at least some cases, the results resembled an extreme trauma to the trapezius nerve bundle, as if the neuro-fibers had been ruptured. (VOY: "Cathexis") The technique did not appear to cause permanent injury and seemed to be effective on most humanoid species. The only Human to have ever been insensitive to it was Gary Seven. (TOS: "Assignment: Earth" ) When used on Human Augments like Khan Noonien Singh, it caused pain but was not enough to subdue them. (Star Trek Into Darkness) It was proven ineffective on robotic androids when Spock took the time to softly try it on android Alice, who simply asked him calmly if that gesture had any significance. (TOS: "I, Mudd" ) Vians were unaffected by the nerve pinch. (TOS: "The Empath" )