Impressive use of acrobatic ability. Very similar to the capoeira 'Au de Costas' - a movement orginialy performed by very famous Capoeira Angola master - Mestre Cobra Mansa, in his days as a street and circus performer. (He is known as the 'creator' of this movement, nowdays very common in breakdancing, capoeira, freestyle acrobatics and sports martial arts)
I do not believe this is realy a traditional performance, but we will let them enjoy the benefit of the doubt....