Animation Optimization: Shoulders, hips, neck?

So I’m fairly certain that the model I’ve got has a nice poly count and some good edge flow, however, when it comes to animation I’ve only seen how to model joints. For something that rotates and bends, like a socket, what is the best way to optimize the joint?

EDIT: forgot to attach my model file.

Also, is there anything you’d recommend for making my model more “efficient”? I’m shooting for something that Xbox 360 can render fairly fast.

Attachments

lab_overseeer(animation ready).blend (646 KB)