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.
Manual of Structural Kinesiology The Shoulder Girdle 4-29 Pectoralis minor muscle Downward rotation: as it abducts, it draws scapula downwardAbduction (protraction): draws scapula forward & tends to tilt lower border away from ribsDepression: when scapula is rotated upward, it assists in depression.