Arm study

Me encanta aunque primero en el boceto podrías aplicar trazos más suaves y no marcar tanto hasta el final y en dónde tenga una sombre más pronuncia pero en cuanto a la proporción está muy bien, sigue usando figuras, vas muy bien, saludos.

This is good! You've got a good idea of arm shape and in the second picture you really captured the flow of the human arm.

This is amazing! You really showed the muscles and structure of the arm.

This is really great! Easy to tell you already have some good base ground on anatomy. May I sugest to take into more details about each muscle? Every fiber is intertwined (obviously, you don't need to go THAT hard drawing each fiber of our body hehehe), but my point is, you can get a better understanment about how arms work and how the muscles work to make moves going more on how these work, so putting more detailing on shadows, important outlines and features may give you a more fruitful time on studying.

Hope this helps even a itzy bitzy

Best wishes for ya!