I recently completed this image of a person in the deadlift starting position. I highlighted the major muscles worked: Erector Spinae (purple), Gluteus Maximus (blue), Quadriceps (orange) and Hamstrings (green).
I have to admit that even though I have a BS in Biology, I haven’t taken a human anatomy class since high school. Lucky for me there are many books available to help artists create accurate depictions of human muscles and bones. The process ended up feeling like I was putting a puzzle together. The books I referenced are Human Anatomy for Artists by Eliot Goldfinger and Artistic Anatomy by Dr. Paul Richer and Robert Beverly Hale.
Also, thanks to Tommy at Crossfit Ranch in Salinas for posing for me and teaching me about Deadlift basics!