If your shoulders are really flexible, you should be able to touch your elbows together behind your back.
ーIf your shoulders are really flexible, you should be able to touch your elbows together behind your back.
「肩がすごく柔らかいと、背中の後ろで肘と肘をくっつけられるんだって。」
shoulders で「肩」
flexible で「体が柔らかい」
elbows で「肘」
behind one's back で「背中の後ろで」
ご参考まで!