Muscles attached onto the scapula:


Review the attachments, actions and innervation of the muscles attached onto the scapula.
 

Muscle

Origin

Insertion

Innervation

Action


Trapezius

•  External occipital protuberance

•  Along the medial sides of the superior nuchal line

•  Ligamentum nuchae (surrounding the cervical spinous processes)

•  Spinous processes of C1-T12

  • Posterior, lateral 1/3 of clavicle.
  • Acromion.
  • Superior spine of scapula.

•  Spinal accessory (efferent)

•  Ventral ramii C3, C4 (afferent)

•  Elevates scapula

•  Upward rotation of the scapula (upper fibres).

•  Downward rotation of the scapula (lower fibres)

•  Retracts the scapula.

Lattisimus dorsi

•  Spinous process of T7-L5

•  Upper 2-3 sacral segments

•  Iliac crest

•  Lower 3 or 4 ribs

Lateral lip of the intertubercular groove

Thoracodorsal nerve C6,7,8.

•  Adduction of humerus

•  Medial rotation of the humerus

•  Extension from flexed position

•  Downward rotation of the scapula

Deltoid

•  Lateral, anterior 1/3 of distal clavicle.

•  Lateral border of acromion

•  Scapula spine

Deltoid tuberosity of humerus

Axillary nerve C5,6.

•  Abducts the arm

•  Flexion and medial rotation (anterior fibres).

•  Extension and lateral rotation (posterior fibres).

Levator scapulae

Transverse processes of C1-C3 or C4

Superior angle of scapula toward the scapular spine

•  Nerves off cervical plexus, C3,4

•  Dorsal scapular nerve, C5

•  Elevates the scapula.

•  Extends and/or laterally flexes the head.

Rhomboid major

•  Spinous processes of T2-T5

•  Supraspinous ligament

Medial scapula from the scapular spine to the inferior angle

Dorsal scapular nerve, C5

Retract scapula

Rhomboid minor

•  Spinous process of C7 & T1

•  Ligamentum nuchae

•  Supraspinous ligament

Medial margin of the scapula at the medial angle

Dorsal scapular nerve, C5, [C4]

Retract scapula

Subscapularis

Subscapular fossa

Lesser tubercle of humerus

Upper & lower subscapular nerves, C5,6

•  Medial rotation of the humerus

•  Stabilizes the glenohumeral joint

Teres major

Inferior, lateral margin of the scapula.

Crest of lesser tubercle (just medial to the insertion of latissimus dorsi)

Lower subscapular nerve, C5,6

•  Assists in adduction of arm.

•  Assists in medial rotation of arm.

•  Assists in extension from an flexed position.

Teres minor

Middle half of the scapula's lateral margin

Lowest of three facets of the greater tubercle of humerus

Axillary nerve, C5,6

•  Lateral rotation of the humerus.

•  Stabilizes the glenohumeral joint

Supraspinatus

•  Supraspinous fossa

•  Muscle fascia

Uppermost of three facets of the greater tubercle of humerus.

Suprascapular nerve, C5,6

•  Abduction of arm (first 15-20°)

•  Stabilizes glenohumeral joint

Infraspinatus

•  Infraspinous fossa

•  Muscle fascia

Middle facet of greater tubercle of humerus

Suprascapular nerve, C5,6

•  External rotation of the humerus.

•  Stabilizes the glenohumeral joint.

Pectoralis minor

Outer surface of ribs 2-5 or 3-5 or 6.

Medial aspect of coracoid process of the scapula.

Medial pectoral nerve, C8,T1

•  Depresses & downwardly rotates the scapula.

•  Assists in scapular protraction from a retracted position.

•  Stabilizes the scapula.

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CHAPTER 13: Back and Scapula Region