well it involves two steps (2 spacebar move) if done correctly it will break off the arm up to 150 threshold

RELAX all
contract left elbow
right rotate chest
contract left knee
space x1
extent left elbow
extend left wrist

WARNING: do not grip your hands or the arm will fly around and knock you
in the side of your head or take off your arm by momentum alone

Note: if you want to try it out in single player hold all and relax uke for two turns
then try the move with a contracted abs added in the first turn;
(keep uke relaxed), it will knock off his head