Anatomy practice in oil

I've been reviewing and taking notes on a lot of the old masters drawings. I find them to be an intriguing glimpse into the mind of the artist. There is also a wealth of anatomy to learn from them as well.  Now what I really need to do is start copying  them for the practice.

Here is a arm I did a quick free hand drawing of in oil. I don’t think the drawing came out that good and I didn't even fit it all on the canvas.LOL....,but I did figure out some tricks for constructing  muscles in oil .