Lets start with the front view:
- Nr. 1 in this picture is musculus deltoideus. This great piece of our anatomy keeps the humerus save in its socket. It originates in the clavicula (nr 6), the acromion(not in the picture) and a part of the scapula(we dont see that part in the picture but we see Nr. 3 the musculus subscapularis -that is how we can guess the shape). Musculus detoideus is very useful for us because we need him for raising the arm.
Nr. 2 is very famous among body builders but also to most others. It is musculus biceps brachii. It is called biceps because it originates at two places as you can see in the picture. The one origin is at the processus coracoideus the other one is at the scapula. He attaches to the radius. He has many funktions like rotating the forearm and the flexion of the elbow.
Nr. 3 might not be as famous as brachii but is important for the rotation of the upper arm as well as for abduction of it. It originates at the scapula and attaches to the humerus.
Nr. 4 might be new to you as well. It is starting at the processus coracoideus and attached to the humerus. It allows us adduction and inward rotation of the arm.
Nr. 5 starts at the humerus and is super important to bend our elbow. Musculus brachialis is even stronger than musculus biceps brachii. This also has to do with the fact that it attaches to the ulna and not like biceps to the radius.
Nr. 6 is the collarbone.
Nr. 7 is the cubit.
Nr. 8 is the spoke.
I hope you like this little introduction of the muscles of the upper arm and the shoulder because it continues now with the behind view.
Nr. 1 we already know.
Nr. 2 musculus supraspinatus starts at the scapula and attaches to the humerus. It allows us an abduction of the arm until 15%.
Nr. 3 is the brother called musculus infrasinatus. As you can probably see in the drawing it also starts in the scapula and attaches to the humerus. It is important for abduction and adduction of the upper arm
Nr. 4 also starts at the scapula and attaches to the humerus. It is important to have this muscle for it allows us adduction and outward rotation of the upper arm as well as to move it backward.
Nr. 5 musculus teres major had thee same start and ends as the bones as the muscles mentioned before but is not like 2, 3 and 4 a part of the rotors cuff. It allows us inward rotation, retroversion and abduction of the arm.
Nr. 6 is famous for having 3 starting points. That is why it is called musculus triceps brachii. He starts at two different points of the humerus and at the scapula and attaches at the ulna. Thanks to this muscle we can stretch the elbow.
Nr. 7 we know now.
Nr. 8 musculus anconeus has not been known to me before making this drawing. It starts at the humerus and attaches to the ulna. It allows us to stretch the elbow as well.
Nr. 9 we know.