The closed fist would be emblem of the union of different parts which are put together to become stronger: the fist, in fact, enclosing the five fingers of one hand, has a force greater than the sum of the fingers individually taken. Therefore, it has always been understood as symbol of solidarity and struggle. The greeting with the fist closed can be carried out differently: with the right hand or with the left; holding the arm near the body or lifting it upwards. The exact execution has in fact changed and second of the times and political movements. https://uisjournal.com/the-origin-of-the-communist-greeting-with-a-closed-fist-what-is-the-meaning-of-the-gesture/