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Bone: Scapula
Posterior view of the thorax and shoulder girdle. (Scapula visible at either side.)
Gray's subject #50 202
MeSH Scapula
Dorlands/Elsevier s_04/12721810

In anatomy, the scapula, or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone).

The scapula forms the posterior part of the shoulder girdle. In humans, it is a flat bone, roughly triangular in shape.



It has two surfaces, three borders, and three angles.

The anterior (front) side of the scapula shows the fossa subscapularis (subscapular fossa) to which the subscapularis muscle attaches. In animals, this side is referred to as medial or costal (since it faces the ribs and the middle part of the animal) and also shows the facies serrata, for the insertion of the ventral serratus muscle.

The posterior surface (lateral in animals) of the scapula is divided by a bony projection, the spina scapulae (opposite to the fossa subscapularis) into the supraspinous fossa and the infraspinous fossa. This projection is called the spine of the scapula. It begins flat at the base of the shoulder bone, ascends in distal direction to its peak at about the middle of the scapula, this peak is called tuber scapulae. After this peak the spina scapulae steeply decays in height. For humans and carnivores and bovinae the spina runs into a forward pointing hook called acromion, which continues past the main part of the bone.

Another hook-like projection comes off the lateral angle of the scapula, and is called the coracoid process. The end of this hook is the site of attachment of many muscles, such as the coracobrachialis muscle.

Near the base of the coracoid process, so also on the lateral angle, there is a depression called the glenoid cavity. This forms the socket that the head of the humerus articulates with.

The scapula also articulates with the clavicle, via the acromion process (the acromioclavicular joint).


The following muscles attach to the scapula:

Muscle Direction Region
Pectoralis Minor insertion coracoid process
Coracobrachialis origin coracoid process
Serratus Anterior insertion medial border
Triceps Brachii (long head) origin infraglenoid tubercle
Biceps Brachii(short head) origin coracoid process
Subscapularis origin subscapular fossa
Rhomboid Major insertion medial border
Rhomboid Minor insertion medial border
Levator Scapulae insertion medial border
Trapezius insertion spine of scapula
Deltoid origin spine of scapula
Supraspinatus origin supraspinous fossa
Infraspinatus origin infraspinous fossa
Teres Minor origin lateral border
Teres Major origin lateral border
Latissimus Dorsi (a few fibers) origin inferior angle
Omohyoid origin superior border


Figure 1 : Left scapula. Costal surface.
Figure 2 : Left scapula. Dorsal surface.
Figure 3 : Left scapula. Lateral surface.


The costal or ventral surface [Fig. 1] presents a broad concavity, the subscapular fossa.





The dorsal surface [Fig. 2] is arched from above downward, and is subdivided into two unequal parts by the spine; the portion above the spine is called the supraspinatous fossa, and that below it the infraspinous fossa.







The Acromion



There are three borders of the scapula:

  • The vertebral border (or "medial border") is the longest of the three, and extends from the medial to the inferior angle. It is referred to as the dorsal border in animals.


There are three angles:

  • The medial angle (or "superior angle"); craneal angle in animals.
  • The inferior angle; caudal angle in animals.
  • The lateral angle; distal or articullary angle in animals.





Movements of the scapula are brought about by scapular muscles:

Elevation, Depression, Protraction, Retraction, Lateral rotation, (Medial rotation)

Additional images



Additions have been made from "Nickel; Schummer; Seiferle; Lehrbuch der Anatomie der Haussäugetiere.

See also

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Scapula". A list of authors is available in Wikipedia.