I just baptized a new sketch book. Lately I’ve really been trying to work on my anatomy skills. Musculature is tricky business. It helps to think of human muscles as strands woven in a basket, or braided hair. The major muscles wrap about each other, slipping over and under in mischievous ways that are, at times, counter intuitive.
Drawing muscles can be as simple or complex as you choose to make it. Getting extraordinarily detailed renditions such as d’Vinci requires a lot of study of individual muscles. For this, I recommend “Anatomy Drawing School” by Andras Szunyoghy, which you can pick up at Borders in the bargain bin section for $10. It’s actually a reprint of an earlier book that I got long ago. Be forewarned, however, this book is deadly. It’s so hefty you could use it to beat undead with in a zombie apocalypse.
Otherwise, Christopher Hart has an very useful book called “Human Anatomy Made Amazingly Easy” for drawing simplified-yet-graceful muscles. The real boon of this book is that it looks at how muscles act in different positions- raised arms versus lowered ones, tilted heads, etc. It’s also a wee bit lighter. I suggest that you only use this book as a study for bodies, though, and not heads. For some reason the faces in it are very awkward.
Actually, I didn’t use any reference for this drawing, and it shows. But I did this exercise to test my memory of human musculature, not how well I could draw them. In that respect I think I am improving. What I truly need to work on is how they act in different poses.