THE SHOULDER GIRDLE
a. General. The shoulder girdle attaches the free upper extremity (arm) to the
trunk. The scapula has no direct or indirect connection with its counterpart of the
opposite side. It is only indirectly attached to the trunk by means of the clavicle that
closes the girdle ventrally (in front). The girdle remains open dorsally (in back) and is
The terms "tubercle" and "tuberosity" are used interchangeably.
b. The Scapula.
(1) The scapula, or shoulder blade (figure 2-6), is a large, flat, triangular-
shaped bone with several marked processes. It is situated on the dorsal aspect of the
thorax and is attached by muscles only. It lies between the levels of the second and
seventh ribs with its vertebral border about two inches lateral to the vertebral column. In
thin subjects, it can be easily palpated. It has two surfaces, three borders, and three
angles which can be recognized.
(2) The anterior surface of the scapula is directed toward the ribs and is
comparatively smooth. It is marked by a concave and somewhat shallow depression,
termed the subscapular fossa. The posterior surface is slightly convex and is divided
into two unequal areas by a narrow ridge or crest of bone called the spine. The spine of
the scapula terminates laterally in a large triangular projection, the acromion process,
which forms the tip of the shoulder and can be felt through the skin. The portion of the
posterior surface above the spine is called the supraspinous fossa; and below it, the
(3) The three borders are designated as the vertebral, the axillary, and the
superior. The vertebral border is approximately parallel to the vertebral column. The
upper (superior) border is the shortest and is thin and sharp. At its lateral end, there is
a depression, the scapular notch, and a thick beaklike projection, the coracoid process.
The coracoid process curls forward beneath the clavicle and can be palpated in a
depression on the thorax (the infraclavicular fossa). Frequently, in thin subjects, it may
form a rather prominent projection. The axillary border is the thickest and lies close to
the armpit, or axilla.
The three angles are designated medial, inferior, and lateral.
(a) The medial angle is formed by the junction of the superior and
(b) The inferior angle is formed by the union of the vertebral and