Critique on structure and proportion

hhey first time posting!
Drawing only female read models with pen and paper, 7 poses for 2 min and 3 more poses with as much time as i need.
The goal of this practice was accuracy of orientation of the major masses of the body and proportion. I had difficulties with n°9 because of the sideview and overlapping of shape (with the pelvis, the bent leg and arm). I’d like to find a better way to draw joints for limbs cuz it can get a bit convoluted especially when bent.
Feel free to critique, and suggest ways of drawing joints.

https://drive.google.com/file/d/1rO0mXvksthqO-yfZ3brk-bIyl_9C3F3X/view?usp=sharing
https://drive.google.com/file/d/1SbwGsW6-66WBAL6zr45lQ5wiqoehnabv/view?usp=sharing

The use of 3D shapes (cylinders, cubes, spheres) is great and you have utilised them well. 

Have a go at using more natural shapes (still make them 3D) instead of the boxes for the pelvis and rib cage. If you do this, (rounding the edges slightly etc) you will find it closes to the anatomy and will find it easier to adapt the poses and build a drawing from them.

I love your use of 3d shapes to make the body! I’d would say the next step for you would be making the shapes more organic which helped me personally with understanding overlap. Thinking about how fat and muscle sits makes a lot of poses make more sense.

Also about joints, remember that specifically with the elbows and knees that the joint is like a hinge and not a ball socket like in the hips and shoulder. I don’t know how much that helps but thinking of all joints as the same is how a lot of beginners see it so I thought I should bring it up. Loved loved loved it!!!