The scientific name of this region of the human body is gluteus maximus. Certainly, for the women in video below, maximus is the right name for their buttocks.
Premier Productions - or ToughGirls as they display on their site, has been a regular supplier of fights with buff girls for at least two decades (the video below is from 1989). Besides the female vs female genre - which has been mostly topless since a long time, they cater also for the mixed wrestling fans. Curiously, in this case, the male wrestlers are always anonymous... and losers.
I will be back with more comments and images about Premier Productions.