Muscles of the Superficial Back

Question 1

Trapezius Upper (Descending)

Answer 1

Origin: Superior nuchal line - nuchal ligament, External occipital protuberance, C7 Spinous process

Insertion: Lateral clavicle, acromion process

Innervation: Accessory nerve (CN X1 (11))

Function: Elevates the scapula, Rotates head to opposite side, Capital and cervical extension

Question 2

Trapezius Middle
(Transverse - fibers travel horizontally)

Answer 2

Origin: T1-T12 Spinous processes - supraspinous ligaments

Insertion: Acromion process, spine of scapula

Innervation: Accessory nerve (CN X1 (11))

Function: ADduct scapula

Question 3

Trapezius Lower
(Ascending - fibers travel up)

Answer 3

Origin: T1-T12 Spinous processes - supraspinous ligaments

Insertion: Spine of scapula

Innervation: Accessory nerve (Cervical plexus C3-C4 inn.) (motor, pain & proprioception)

Function: ADduct, depress, and unwardly rotate scapula

Question 4

Latissimus Dorsi

Answer 4

Origin: Thoracolumbar fascia, Iliac crest

Insertion: Intertubecular sulcus of humerus

Innervation: Thoracodorsal nerve (Dorsal rami)

Function: ADduct, extend, internally rotate shoulder, hyperextension of spine

Question 5

Levator Scapulae

Answer 5

Origin: C1-C4 cervical transverse processes

Insertion: Superior angle of scapula, vertebral border of scapula above spine

Innervation: Ventral rami C5 Dorsal Scapular n.

Function: Elevates and ADducts scapula, scapular downward rotation, lateral bending of cervical spine to same side, cervical rotation to same side, cervical extension

Question 6

Rhomboid Major

Answer 6

Origin: Spinous processes T2-T5, supraspinous ligament

Insertion: Inferior medial scapula

Innervation: Ventral rami C5 dorsal scapular nerve

Function: Scapular ADduction, downward rotation, elevation

Question 7

Rhomboid minor

Answer 7

Origin: C7-T1 spinous processes

Insertion: Vertebral border of scapula at level of superior angle

Function: Scapular ADduction, scapular downward rotation, and elevation

Innervation: Ventral rami C5 dorsal scapular nerve

Question 8

Serratus Posterior Superior

Answer 8

Origin: C7 and T1-T3 spinous processes

Insertion: Upper border ribs 2-5

Function: Elevates ribs

Innervation: T2-T5 ventral rami spinal nerves - Intercostal nerve

Question 9

Serratus Posterior Inferior

Answer 9

Origin: T11 -L2 spinous processes, supraspinous ligaments

Insertion: Lower boarder ribs 9-12

Function: Depresses lowest 4 ribs

Innervation: T9-T12 ventral rami spinal nerves - Intercostal nerve