Winged People Anatomy: Muscles

See this is how much of a procrastinator I am. I've had this and the feathers one sitting on my computer for about a year and it's only really since the sudden influx of favourites of the Bones one that I thought to myself about finishing and posting. 
I kinda liked doing the drawings at the bottom. 
   
Again reference from Bones, Anatomy Ref from www.biodigitalhuman.com/ , medical books, doctors, various sources of photos and ornithological books and diagrams, along with a little bit of logic.