A woman is painfully restrained by the wrists and ankles nearly the entire movie. She is humiliated, sexually assaulted (in some instances violently), beaten and tortured.
The father of the family is physically abusive toward both his wife and eldest daughter on multiple occasions, the later of which it is implied he may be abusing sexually as well.
Children witness and are forced to get involved in things they absolutely shouldn't (including torture and their mum being beaten), and it's very heavily implied that a teen has been raped at least once.