Wow. Fantastic work!

Hi @Madelyn Kuipers, nice studies! - The muscles generally go to the right place, so good job with that👍, but I would try to be more specific about the insertion. I don't necessarily mean putting in every little tendon, you may simplify, but in that simplification it's important that things make sense, so that the arm you've drawn would have been able to move, if it was a real arm. In drawing six for example, you stop the extensor group where the forearm ends. Had this been a real arm, it wouldn't have been able to extend the hand. The extensor group has to attach to the hand in order to extend it. Make sure that each muscle group has a specific point/line where they attach. - If you want to simplify the ridge muscles into a single volume, try to keep it consistent between poses. Comparing #2 and #6, which both are based on muscular models, the simplification isn't consistent from drawing to drawing. In #6 the drawing have indicated a strange split in the middle of the ridge group, which doesn't seem to match the more accurate "Jabba the Hut" shape of #2. I hope this helps :)

On sketch 2, the deltoid is too short. It should be about half the length of the humerus. On sketch 3, the posterior deltoid appears to connect to the acromion process when it actually should come from the spine of the scapula. As such, the trapezius may slightly overlap it. I'd also recommend giving a little more attention to the shapes in your drawings. Try to emphasize the force of the muscles by using curved and sharp lines--"curves and straights." That way, the forms may feel more solid. (Contour lines may also be useful for showing the form of the muscles.) Overall good job.

you did great!

Hi @Madelyn Kuipers, solid studies! You show a good understanding of the arm bones; they are correctly constucted for the most part. - In #1 you've place the radius medially at the humerus, when it should sit laterally - I would study the scapulae with the humerus. You tend to get the head of the humerus slightly misplaced. In #2 for example it's too high up, making the humerus too long. In #4 it should sit more laterally. One thing that has helped me has been to find the head of humerus, and acromion process on my own shoulder. - You get this right for the most part, but in image 4 you've attached the head of the humerus laterally to the shaft of the humerus. The head of the humerus should sit medially to and posterior to the shaft. - In #5 you've place the epicondyles of the humerus too high on the upper arm, making the humerus too short. I think it will help to identify these points on your own arm. It will increase your knowledge of their placement and it can also help you use your imagination to find them on the model. You could ask "where does it feel like I would have my epicondyles if I stood in the same position as the model?". Or you could imagine touching the reference. Since you've touched the epicondyles on you own arm, you can kinda guess where you would have felt them on the model. - In #4 I might extend the radius and ulna a bit longer. See paintover. Again, finding the bones on your own body helps. Hope this helps :)