The Nazi salute came from the USA's early Pledge of Allegiance which began with a military salute that was then extended outward to point at the flag (see the discoveries of the symbologist Dr. Rex Curry, author of “Pledge of Allegiance Secrets”). Dr. Curry debunked the myth that it was an ancient Roman salute, and showed that the myth came from the Pledge of Allegiance. Only part of the story is in an “alternative” explanation that Adolf Hitler acquired the gesture from Ernst "Putzi" Hanfstaengel, the German national socialist press chief, a Harvard graduate and apparent US citizen, who had “copied it from Harvard football cheerleaders.” http://rexcurry.net/swastika-hanfstaengl.html
The missing part of the story is that Harvard football cheerleaders copied it from the USA's pledge of Allegiance. It also shows how the Nazi salute was gaining expanded use in the USA beyond its use in the Pledge of Allegiance (similar to the spread of the gesture in Germany later).
According to Norwood the "stiff-armed Nazi salute and Sieg Heil chant" was "modeled on a gesture and a shout" that Hanfstaengl had used as a Harvard football cheerleader (Norwood cites Karl Dietrich Bracher, German Dictatorship, 117; Peter Conradi, Hitler's Piano Player: The Rise and Fall of Ernst Hanfstaengl, Confidant of Hitler, Ally of FDR (New York, 2004), 45, 63). Here is a funny point about Norwood (and other authors) and Hanfstaengl: It is possible that both were ignorant of the Nazi gesture's origin in the USA's Pledge of Allegiance (written in 1892). Putzi did not grow up in the USA, so when he encountered the gesture later at Harvard, he might not have realized it came from robotic chanting daily in government schools for about two decades prior in the USA. Norwood, on the other hand, is young enough that if he was educated in government schools (socialist schools) in the USA, then he would be ignorant about the pledge, and Norwood is similar to others who write about the Nazi salute (other than Dr. Rex Curry), in that Norwood failed in his research to discover that the gesture was part of daily robotic chanting in government schools in the USA for about three decades prior to German national socialism.
Edward Bellamy and Francis Bellamy were American national socialists and they influenced German national socialists, their rituals, dogma and symbols (e.g. the use of the swastika as crossed S-letters for socialism). Norwood (and all the other authors) seem to be ignorant about that too (and about the role of Ernst Hanfstaengl). http://rexcurry.net/swastika-hanfstaengl.JPG