Spinal Muscles (OSPE)

Question 1

Sternocleidomastoid

Answer 1

Origin:
* Sternal head: anterior surface of manubrium
* Clavicular head: medial 1/3 of clavicle
Insertion: Mastoid process of temporal bone & superior nuchal line of occipital bone
Action: Flexion & lat flexion of neck, head rotation
Innervation: Accessory n., proprioceptive fibers of anterior rami of second to fourth cervical nerves

Question 2

Scalenes

Answer 2

Origin:
* Anterior: TP of C3-C6
* Middle: TP of C2-C7
* Posterior: TP of C4-C6
Insertion:
* Anterior: Scalene tubercle of 1st rib
* Middle: Superior surface of 1st rib
* Posterior: External surface of 2nd rib
Action:
* Anterior: Flexion, rotation, lat flex neck, elevates 1st rib
* Middle & Posterior: Lat flex neck & elevates 1st rib
Innervation:
* Anterior: Anterior rami of 4th, 5th, 6th cervical n.
* Middle: Anterior rami of C3-C8
* Posterior: Anterior rami of C4-C6

Question 3

Splenius Capitis

Answer 3

Origin: Nuchal ligament, SP of C3-T3
Insertion: Mastoid process, lateral 1/3 of superior nuchal line
Action: Rotation, extension of head
Innervation: Posterior rami of C2-C3

Question 4

Splenius Cervicis (Splenius Colli)

Answer 4

Origin: SP of T3-T6
Insertion: TP of C1-C3
Action: Extension, rotation, lat flexion of neck at cervical vertebral joints
Innervation: Posterior rami of lower cervical n.

Question 5

Longissimus

Answer 5

Origin: TP of C4-T6, SP of L1-L5, dorsal surface of sacrum, iliac crest
Insertion: Mastoid process, TP of C2-C6, TP of lumber and thoracic spine, 2nd to 12th rib
Action:
* Extension, rotation, lateral flex of head
* Extension, lateral flex neck & trunk
Innervation: Posterior rami of cervical, thoracic, lumbar nerves

Question 6

Spinalis

Answer 6

Origin: Nuchal ligament, SP of C7-T2 & T11-L3
Insertion: SP of C2-C4 & T2-T8
Action: Extension, lateral flex neck & trunk
Innervation: Posterior rami of lower cervical and upper thoracic n.

Question 7

Iliocostalis

Answer 7

Origin: Angles of rib 3-12, iliac crest, posterolateral sacrum
Insertion: TP of C4-C6, angles of ribs 1-10
Action: Extension, lateral flex of neck & trunk
Innervation: Posterior rami of lower cervical, thoracic, lumbar n.

Question 8

Rectus Abdominis

Answer 8

Origin: Pubic crest & symphysis
Insertion: Xiphoid process and costal cartialge of ribs 5-7
Action: Flexion of trunk, compress & structural support to adjacent abdominal structures
Innervation: Anterior rami of 6-12 thoracic n.

Question 9

Transversus Abdominis

Answer 9

Origin: Costal cartilages of ribs 7-12, thoracolumbar fascia, iliac crest, inguinal ligament
Insertion: Linea alba, pubic crest, pecten pubis
Action: Compression & structural support to adjacent abdominal structures
Innervation: Anterior rami of 7-12 thoracic n., iliohypogastic and ilioinguinal n.

Question 10

External Obliques

Answer 10

Origin: External surfaces and inferior borders of 5th to 12th ribs
Insertion: ASIS, anterior half of iliac crest, pubic crest, pubic tubercle, linea alba
Action: Flexion, lateral flexion, rotation of trunk. Compress & structural support for adjacent abdominal structures
Innervation: Anterior rami of 7th to 12th thoracic n.

Question 11

Internal Obliques

Answer 11

Origin: Thoracolumbar fascia, iliac crest, inguinal ligament
Insertion: Inferior margins of 10th to 12th and adjacent costal cartilages, linea alba, pecten pubis
Action: Flexion, lateral flexion, rotation of trunk. Compress & structural support to adjacent abdominal structures
Innervation: Anterior rami of 7th to 12th thoracic n., iliohypogastric and ilioinguinal n.

Question 12

Quadratus Lumborum

Answer 12

Origin: Posterior half of iliac crest, iliolumbar ligament
Insertion: Inferior border of 12th rib, TP of L1-L4
Action: Extension and lateral flexion of trunk, stabilizes 12th rib during inspiration
Innervation: Anterior rami of 12th thoracic & 1st-4th lumbar n.