Lower Back Caning?
It’s possible we just have a bad camera angle, but it looks for all the world like this poor young lady is getting a painful caning on her lower back:
From Lupus.
See Also:
Spanking Blog: Adult Erotic Spanking At Its Best
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Bondage Ass Beatings Movie:
Detention House 3: Severely Punished Delinquent Girls
"...and then the spanking starts. Brutal, totally uncompromising. You have never heard screams and shrieks as terrible as these..."
A rope, belt, or whip to the back is a classic painful punishment. Anything hard sounds dangerous on the back.