Try to improve human drawing

I like to draw human and I will draw them when I am bored. However I don’t know where is the right place of the muscles of the arms and legs when every times I tried to draw them. I want to draw my character more realistic. Therefore, I am going to find out the actual placement of each muscle of the arm this time.

I searched some information and images on Pinterest and found out the name of the muscles of the parts of arm. I tried to draw them below.

1.           Deltoid

2.           Triceps brachii

3.           Biceps brachii

4.           Brachialis

5.           Brachioradials

6.           Flexor carpi ulnaris

7.           Flexor Carpi Radials

I also tried to imagine and test how they look like in different angles in one pose:

The scale is wrong but never mind. That was just testing. I will improve next time.