社交舞
In American tango, the partners shift their shoulders, hips and heads to a variable degree less and up to 90 to that of their original position, while their feet: man's left; lady's right are rotated respectively leftward and rightward to make a "V" (to the left/right). This exact position is also called semi-open in some dance books, by some authors and teachers, especially in American Smooth Ballroom dance.