I remember when this story broke out, she had been locked outside to 'discipline' her about her attitude, she collapsed, and the parents didn't take direct action because of their dogmatic view for quite a while. There are some articles with their emergency call/being interviewed and it's chilling how these children are talked about. They are objects towards a goal of being seen as good disciples and nothing else.
This type of 'discipline' is heavily pushed in a lot of evangelical circles (the American right-wing style ones). Even in less physical methods, the very detached, 'they're born wicked and you have to break them to comply with your will for them' mentality is taught over and over. I was raised in this environment and it's only gotten worse in my experience. The push to use this type of things is being pushed a religious right thing to do to create soldiers of God. Even more heartbreaking, these same circles are also part of the movement pushing to adopt more kids from abroad. Adoption laws vary from state to state in America and in some abroad adoption is quite easy compared to local ones - this couple had at least two children adopted alongside some birth children if I remember correctly - and there have been a lot of reports going around about this violent method of parenting has become racialised through this (seriously, there are writings from these organizations and form groups that encourage this that discuss how children from these countries "need an even firmer hand" and have extremely abusive measures and encourage using birth children/white church children as disciplines (bullies) to get these adopted children to break.
It's disturbing, disgusting, abuse. Many people are fighting this sort of thing, but many of those in charge are also part of these evangelical movement and/or at least get a lot of their votes and funding from them. The first step many are pushing for is better regulation in the States of adoptions from abroad because those children face the worst of it, then move onto abuse laws because that will be far harder with the control the church has.