>>370439603
Assuming you don't mean hair coming out of your knees or something, you just need to make a new bone parented to the head bone and weight paint to it to that then make it a dynamic bone in unity although you presumably already know this so your question doesn't really explain what your problem is. Is it moving too sharply? Not enough? If it is literally just stuck to your head then it's because you haven't made the bones dynamic.