Rueda de Casino/Arriba

The leaders walk forwards and the follower walks backwards, in normal salsa timing, keeping within the circle. This is done in the initial position (men facing anti-clockwise).

Arriba can also be used (like abajo can) to affect other moves.

For example, enchufa de arriba means that when you change partners, you move one forwards instead of backwards (more specifically, you move to the follower who is next, anti-clockwise).

Another obvious example is adios de arriba.