back- intermediate muscles + deep muscle (erectie spinae group)

Serratus Posterior Superior — Origin?

• Nuchal ligament

• Spinous processes of C7–T3

Serratus Posterior Superior — Insertion?

• Superior borders of ribs 2–5

Serratus Posterior Superior — Action?

• Elevates ribs 2–5 (assists inspiration)

Serratus Posterior Superior — Innervation?

• Intercostal nerves 2–5

Serratus Posterior Superior — Blood Supply?

• Intercostal arteries 2–5

Serratus Posterior Inferior — Origin?

• Spinous processes T11–L2

Serratus Posterior Inferior — Insertion?

• Inferior borders of ribs 9–12 (near angles)

Serratus Posterior Inferior — Action?

• Depresses ribs 9–12

Serratus Posterior Inferior — Innervation?

• Intercostal nerves 9–11

• Subcostal nerve (T12)

Serratus Posterior Inferior — Blood Supply?

• Intercostal arteries 9–11

Spinalis — Origin?

• Posterior iliac crest

• Posterior surface of sacrum

• Sacroiliac ligament

• Sacral & inferior lumbar spinous processes

• Supraspinous ligament

Spinalis — Insertion?

• Spinous processes (upper thoracic → cervical → cranium depending on part)

Spinalis — Action?

• Bilateral: Extends head, cervical & thoracic spine

• Unilateral: Lateral flexion

Spinalis — Innervation?

• Dorsal rami of spinal nerves

Spinalis — Blood Supply?

• Lateral sacral arteries

Longissimus — Origin?

• Common erector spinae tendon (same as spinalis origin):

  • Iliac crest

  • Sacrum

  • Lumbar spinous processes

Longissimus — Insertion?

• Ribs (between tubercles & angles)

• Transverse processes (thoracic & cervical)

• Mastoid process (capitis portion)

Longissimus — Action?

• Bilateral: Extends head, cervical, thoracic & lumbar spine

• Unilateral: Lateral flexion

Longissimus — Innervation?

• Dorsal rami of spinal nerves

Longissimus — Blood Supply?

• Intercostal arteries

• Lumbar arteries

Iliocostalis — Origin?

• Common erector spinae tendon:

  • Iliac crest

  • Sacrum

  • Lumbar spinous processes

Iliocostalis — Insertion?

• Angles of ribs

• Cervical transverse processes

Iliocostalis — Action?

• Bilateral: Extends vertebral column

• Unilateral: Lateral flexion

Iliocostalis — Innervation?

• Dorsal rami of spinal nerves

Iliocostalis — Blood Supply?

• Intercostal arteries

• Lumbar arteries