There are some problems with the mesh, and there are some problems with the joint parameters, particularly where the arms meet the chest.

However, I have to argue with protests that his anatomy is completely off. Mike 2 is hardly a good metric for that. Here is a picture of Mike 3 side-by-side with the male model from Atlas of teh Human Anatomy for the Artist, by Stephen Rogers Peck (hopefully OK under fair use and de minimus. I'm not wanting to step on anyone's copyright here).