Reclining

I looked at your other drawings. The back study is especially good. The others are also good. In the drawing, I am critiquing you are concerned about the head. I do not see any problem with it. It and the rest of the figure look good.

I am going to recommend you do a side study of human anatomy - muscles & bone structure. In the long run, the study will do you good. be sure to do drawings of what you find. If you are drawing a figure from any angle, your knowledge of anatomy will pay off. I am not saying your current knowledge is bad but the study will in the long run pay off for you. You can find a lot of information on the internet for free.

Also, practice makes better. So practice, practice, and practice some more.

Keep drawing!

There is a lot of structure in the back. Study the muscles in the bank & bone structure. Find black & white photos which also will show you the structure in the back. Backs can be very interesting. You need to practice doing them. Your study of a women's back is very good. Keep it going.

Good job at capturing the pose. The arms seem a bit short and you could go a bit darker with the shading in some parts but overall I'd say it's pretty decent.

The shadows are perfect, but i know u can let the contrast higher. The other details, like the face u didn't liked, will ge better with time.