Intermediate Back

Question 1

Intermediate Back Muscles: What is their overall function? What are they innervated by?

Answer 1

• Move the ribs during respiration
• Innervation: Intercostal Nerves (anterior rami of thoracic spinal nerves)

Question 2

Answer 2

Serratus Posterior Superior

Deep to rhomboids

Origin:

• Ligamentum Nuchae

Insertion:

• 2-4th Ribs

Innervation:

• Intercostal nn.

Action:

• Elevates ribs

Blood Supply:

• Posterior Intercostal aa.

Question 3

Answer 3

Serratus Posterior Inferior

Deep to latissimus dorsi

Origin:

• Spinous processes T11-L2

Insertion:

• 8th-12th Ribs

Innervation:

• Intercostal nerves

Action:

• Depresses Ribs

Blood Supply:

• Posterior Intercostal aa.