Introduction to the subject
Little known, because the clavicle and the scapula are not highly preserved. Most of the time not complete (10). It is a relatively understudied subject (17).
400,000 year old throwing spears discovered

Shoulder
Clavicle and scapula, humerus and the joint, some ligaments…
The hominin shoulder passed through various different stages from our early ancestor to know (10)
The clavicle is the only skeletal anchor to the torso, so this bone is very important in throwing because the torso is used. The clavicle length is also an important measure to know the position of the scapula (17)
The pectoral girdle or shoulder girdle is the set of bones, which connects the upper limb to the axial skeleton on each side. It consists of the clavicle and scapula in humans and, in those species with three bones in the pectoral girdle, the coracoid.
The glenoid cavity (or glenoid fossa of scapula from Greek: gléne, "socket") is a part of the shoulder. It is a shallow pyriform, articular surface, which is located …show more content…
Low humeral torsion found in hominins supports the idea that the high levels of humeral torsion found in apes and humans has developed independently. If non-Western groups are viewed as a standard the humeral torsion of the modern Homo, H. neanderthalensis and even H. heidelbergensis are quite similar.
Finally, the wide shoulders characteristic of Homo act to increase the counter- balancing moments generated by arm-swinging, while also permit- ting energy-saving reductions in forearm mass (2).

How did it happened?
I suggest that the clavicular elongation that occurred in the human lineage subsequent to early H. erectus was most directly related to dorsal repositioning of the scapula, and that this shift in scapu- lar position occurred in order to increase the range of motion of the upper