Deep Back Muscles

Question 0

Serratus Posterior Inferior

Answer 0

Origin: spinous processes of T11-L2

Insertion: inferior border of 8-12 ribs near the angles

Innervation: 9-11th intercostal nerves and subcostal nerve (T12)

Action: depress the ribs

Question 1

Serratus Posterior Superior

Answer 1

Origin: nuchal ligament, spinous processes of C7-T3

Insertion: superior borders of 2-4 ribs

Innervation: 2-5th intercostal nerves

Action: elevate the ribs

Question 2

Splenius Capitis

Answer 2

Origin: nuchal ligament, spinous processes of C7-T6

Insertion: mastoid process and lateral third of the superior nuchal line

Innervation: posterior rami of spinal nerve

Action: bilaterally extend the head and neck and unilaterally lateral flex and rotate head to the same side

Question 3

Splenius Cervicis

Answer 3

Origin: nuchal ligament, spinous processes of C7-T6

Insertion: tubercles of transverse processes of C1-C3

Innervation: posterior rami of spinal nerve

Action: bilaterally extend the head and neck and unilaterally lateral flex and rotate head to the same side