Help D:

I'm working on my comic, and this is one of the last two horses I'll have to do (and then this page is ready for uploading), but this just doesn't feel right. Something in the anatomy is wrong. Awefully wrong! It's hard for me to imagine the horses' skeleton and muscles seen from the back, and also from above. So I need a bit of help. Is there someone who can explain it by redlining? English is not my primary language so I think I'll understand it better visually. Any help is appreciated!

This is my reference: by ~Wilds-Stock aka *Wild-Hearts (check both of her galleries c: )
Though I don't think it'll help you that much, I didn't really draw it according to the reference.