The assault of one's
testicles from behind.
Generally, the victim is bent over, however a standing attack up the legs is also commonplace.
Often times, the assailant will yell "back sack attack!" either at contact, or
after the strike is complete.
Winding up for a kick, Ben positioned himself behind a bent-over Matt. Using mostly the flick of his foot unto the scrotum, Ben yelled "
Back sack attack!" before Matt ever got the chance to react. Devolving into his
fetal position, Matt sat writhing in pain.