shurg--an uncontrollable spasm of the shoulders; a seizure-like shrug;
Distinctly resembles Wacky Waving Inflatable Arm Flailing Tube Man on crack, twitching sporadically and muttering nonsense.
Or...another analogy would be Helen Keller having a heart attack inside an insane asylum...
Jon consumed a can of Monster, Red Bull, 5-hour energy, and cocaine all in one sitting. He started to shurg, convulsing wildly on the floor.