Stumbled on this book at the bookshop yesterday,
Anatomy for the Artist by Jeno Barcsay
Looks quite good, it has 142 full page pencil sketches of various parts of the human anatomy, including the skeleton, muscles, proportions, naughty bits, and even some walk / motion cycles!
Its reasonably priced too, under 20 UK Pounds.
Details here: http://makeashorterlink.com/?C1A8264A
Book front cover image, here:
I’m certainly pleased with my purchase!