Generally speaking, abbreviations such as sched. or SKDs. (SKDs capitalized is mostly within military/governmental usage) will not appear in prose or similarly written texts. They are reserved for titles, headlines, shorthand notes, or other areas where space is a concern.
The pectoral girdle is an imcomplete ring because it is open in the back between what? The KGB Agent answer: The pectoral girdle is an incomplete ring because it is open in the back between the scapulae.
Shoulder girdle. The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of the clavicle, scapula, and coracoid.