Inroduction[edit | edit source] Show
The scapula is a thin, flat triangular-shaped bone placed on the postero-lateral aspect of the thoracic cage. It has 2 surfaces, 3 borders, 3 angles and 3 processes. Image: Overview of the scapula bone - anterior view[1] Osteology[edit | edit source]The main part of the scapula, the body, consists of a somewhat triangular-shaped flat blade, with an inferiorly pointing apex, referred to as the inferior angle as well as lateral and superior angles. The scapula is described as having superior, medial, and lateral borders.
Image 2: Dorsal view of the scapula Angles
Watch this 3 minute video for a recap.[3] Attachments on Scapula[edit | edit source]Scapula has various bony projections for attachment of muscles, ligaments and other soft-tissue structures.[4] Muscles[edit | edit source]17 muscles attach to the scapula!
Ligaments[edit | edit source]
Bursae[edit | edit source]There are two major bursae:
Biomechanics[edit | edit source]The scapula upwardly rotates in the frontal plane, posteriorly tilts in the parasagittal plane, and externally rotates in the transverse plane during functional elevation. Scapular control is essential to scapulohumeral coordination. Posterior tilting is responsible for humeral clearance during the acromiohumeral portion of shoulder elevation. Fung et al discovered that scapular upward rotation and retraction are greatest during abduction elevation, when compared to flexion elevation. They also discovered that posterior tilting was greatest during flexion elevation. Any disturbance in this rhythm can decrease scapulothoracic movement and can be associated with fatigue, impingement, instability, and limits in elevation. [4] [5] [edit | edit source]
References[edit | edit source]
What are the two prominent projections of the scapula?A prominent ridge or spine divides the dorsal surface into two, unequal parts called the supraspinous fossa and infraspinous fossa. A shallow depression at the lateral angle called the glenoid cavity. accepts the head of the humerus to form the shoulder or gleno-humeral joint.
What is a slightly concave projection of the scapula?The coracoid process is the finger-like projection of bone from the anterior surface of the scapula, palpable about 1 inch below the most concave portion of the distal clavicle. The coracoid process is the site of attachment for several muscles and ligaments of the shoulder complex.
What is the coracoid process of the scapula?The coracoid process is an osseous structure that arises from the superior border of the head of the scapula, projecting forward and curving laterally. The coracoid process is located directly below the lateral fourth of the clavicle and connected to its undersurface by the coracoclavicular ligament.
What are the names of the three borders of the scapula?The scapula has three angles (superior/medial, lateral, inferior), three borders (medial, lateral/axillary, and superior), and two surfaces (ventral and dorsal).
|