Physical abuse is well hidden, floo. There have to be wounds or a real crisis for it to become known so most of us would not recognise it. The victims come in all shapes, sizes and types - often the last people you would expect. Men tend to hide it well too.
It often goes hand in hand with psychological abuse, same as with women and is extremely difficult to get away from.
I really feel like weeping right now thinking about all this. So many damaged people hurting eachother, what's the point of it all?