Various muscles and ligaments attach on scapula that are used to stabilize and move the bone. Movement of scapula helps in movements of shoulder joint.
- The subscapularis arises from the medial two thirds of the subscapular fossa.
- The serratus anterior is inserted along the medial border of the costal surface-one digitations to the superior angle, two digitations to the medial border, and five digitations to the inferior angle.
- The supraspinatus arises from the medial two thirds of the supraspinous fossa (including the upper surface of the spine).
- The infraspinatus arises from the medial two thirds of the infraspinous fossa (including the lower surface of the spine).
- The deltoid arises from the lower border of the crest of the spine and from the lateral border of the acromion.
- The trapezius is inserted into the upper border of the crest of the spine and into the medial border of the acromion.
- The long head of the biceps arises from the supraglenoid tubercle; and the short head from the lateral part of the tip of the coracoid process.
- The coracobrachialis arises from the medial part of the tip of the coracoid process.
- The pectoralis minor is inserted into the medial border and superior surface of the coracoid process.
- The long head of the triceps arises from the infraglenoid tubercle.
- The teres minor arises from the upper two thirds of the rough strip on the dorsal surface along the lateral border.
- The teres major arises from the lower one third of the rough strip on the lateral aspect of the lateral border.
- The levator scapulae is inserted along the dorsal aspect of the media border, from the superior angle up to the root of the spine.
- The rhomboideus minor is inserted into the medial border (dorsal aspect) opposite the root of the spine.
- The rhomboideus major is inserted into the medial border (dorsal aspect) between the root of the spine and the inferior angle.
- The inferior belly of the omohyoid arises from the upper border near the suprascapular notch.
- The margin of the glenoid cavity gives attachment to the capsule of the shoulder joint and to the glenoid labrum.
- The margin of the facet on the medial aspect of the acromion gives attachment to the capsule of the acromioclavicular joint.
- The coracoacromial ligament is attached
- To the lateral border of the coracoid process, and
- To the medial side of the tip of the acromion process.
- The coracohumeral ligament is attached to the root of the coracoid process.
- The coracoclavicular ligament is attached to the coracoid process: the trapezoid part on the superior aspect, and the conoid part near the root.
- The suprascapular ligament bridges across the suprascapular notch and converts it into a foramen which transmits the suprascapular nerve. The suprascapular vessels lie above the ligament.
- The spinoglenoid ligament bridges the spino-glenoid notch. The suprascapular vessels and nerve pass deep to it.
- Paralysis of the serratus anterior cause ‘winging’ of the scapula. The medial border of the bone becomes unduly prominent, and the arm cannot be abducted.
- In a developmental anomaly called scaphoid scapula, the medial border is concave.
Text adapted from: Human Anatomy by BD Chaurasia
Image Credit: Wikipedia