>>7642856
I think your hand should not go behind the back like in your sketch. You can try it and it's just an awkward pose, especially to hold your weight on, unless done out of desperation. You get a poor grip and your arms cannot exert force properly to pull you back up. Picrel basically. Start the shoulder in line with the other and then bend it inwards with some stress on her biceps.

The way you do it would be fine if she were hanging by a thread of her life or if it were part of a strong motion arc.

Still a beg understanding poses so pardon me if that looks wrong.