One Armed Boxer is a 1971 Hong Kong martial arts film starring Jimmy Wang Yu. It is about a skilled Chinese martial artist who loses an arm and must exact revenge on his rival school.
For the film, Wang Yu, who has both of his arms in real life, had his right arm strapped to his back, and in some shots his other arm can be briefly seen. Released worldwide during 1972, the film came to the United States in late 1973 with a name change: it was released to U.S. theaters as The Chinese Professionals.
(Summary from Wikipedia)