The triceps need to be contracted to extend the wing. I thought that the chicken bones felt smooth because of the liquid outside of it. the chicken wing did not have fingers like a human although it had a wrist.
The chicken wing works just like a human arm with some little differences. The shoulder joint is a ball and socket joint just like a human shoulder, the elbow joint is a hinge joint like a human elbow and the wrist is ball and socket too. When the bicep between elbow and wrist contracts the triceps on the other side is un-contracted. One thing you can try this is put your finger in the two bones in the middle and move the hand up and down and the shoulders will move.
A human arm has shoulder, elbow, and wrist like how chicken has them. The muscle structures are the same with a human arm and chicken wing. They both have biceps and triceps with some bones. There are no fingers on chicken like how a human does.
The chicken can only fly a little, but the structure is made for flying. The wing is flat and wide which makes the chicken able to fly.
The human can lift up a lot of things. The structure is same, but the size of the muscles are very different from the chicken wing which makes a human lift up heavily things. Also, the fingers allow a human to hold things easily.