Wow, I found a great new resource! On Yo/uTub/e there is a channel named Anatomy Zone which has wonderful 3D models displayed, described, and articulated in plain language at a good speed. The curator is using a very cool program that allows one to pick which system of the body to overlay onto a model, in combination with each other.
I highly recommend it to artists who struggle with the feet, just to see the muscles and bones in a little more detail than a single perspective illustration. It’s really helped me out.
Check out the whole playlist about the Lower Limbs: https://www.youtube.com/playlist?list=PLF951931B19317229. The other playlists are organized wonderfully. If you need learning of the nerves and not just muscles for illustration or rendering, it can teach you pretty general anatomy. It feels like a good textbook aide.