Superficial and Intermediate Back Muscles

Question 1

Trapezius

Answer 1

O: superior nuchal line, external occipital protuberance, nuchal ligament and spinous process of C7-T12
I: lateral third of clavicle, acromion and spine of scapula
A: elevates, retracts, and rotates the scapula; lower fiber depress scapula
I: CN XI, C3-C4

Question 2

Latissimus dorsi

Answer 2

O: spinous process of T7-T12, thoracolumbar fascia, iliac crest, and last 3-4 ribs
I: humerus
A: extends, adducts, and medially rotates humorous
I: C6-C8

Question 3

Levator scapulae

Answer 3

O: transverse process of C1-C4
I: superior angle of scapula
A: elevates scapula and tilts glenoid cavity inferiorly
I: C6-C8

Question 4

Rhomboid minor/ Rhomboid major

Answer 4

O: minor- nuchal ligament and spinous processes of C7-T1; major- spinous processes of T2-T5
I: medial boarder of scapula
A: retracts scapula, rotates it to depress glenoid cavity and fix scapula to thoracic wall
I: C3-C4 and C5

Question 5

Serratus posterior superior

Answer 5

O: ligamentum nuchae, spinous processes of C7-T3
I: superior aspect of ribs 2-5
A: elevates ribs
I: T1-T4

Question 6

Serratus posterior inferior

Answer 6

O: spinous process of T11-L2
I: inferior aspect of ribs 9-12
A: depresses ribs
I: T9-T12