The etymology of the word バックシャン


What is the etymology of the word バックシャン? I understand it commonly refers to a
woman beautiful only from behind. See this definition-

> 女性のうしろ姿が均整がとれて美しいこと。また、その女性。多く、前から見ると失望するような 場合にいう。

I understand the back/バック part, but is the シャン a version of ちゃん? When did it
come into common usage?




It is a compound of English "back" and German "schön" ("beautiful").




It is a compound of English "back" and German "schön" ("beautiful").

