Region of the body incorporating the shoulder blade, the shoulder joint and the surrounding muscles. 

The shoulderjoint is a multiaxial ball and socket joint (alowing movement in many planes) between the glenoidal cavity of the shoulder blade and the head of the humerus.  

A flat wedge shaped bone that is the most proximal bone of the forelimb. It is firmly attached to the ribcage with fibrous tissue. Articulates with the humerus (upper arm bone) to form the shoulder joint at its distal end.