Cervical & Thoracic Spine myology

Question 1

Sternocleidomastoid

Answer 1

*Origin: Sternal head: manubrium, clavicular head: medial 1/3rd clavicle.
*Insertion: Mastoid process and nuchal line.
*Action: flexion of the neck bilaterally, lateral flexion to the same side. Rotation to the opposite side.
*Innervation: cranial accessory nerve (XI), anterior primary rami C2,3

Question 2

Scaleni

Answer 2

*Origin:
-Anterior - C3-6 TVP’s
-Medius – C1-7 TVP’s
-Posterior – C4-6 TVP’s
*Insertion: 1st rib (anterior- scalene tubercle, medius- 1st rib)
-Posterior 2nd rib
*Action: together flex neck to the same side and in reversed origin/insertion lift the ribs to aid in forced inspiration
*Innervation: all anterior primary rami
-Anterior- C4-6
-Medius- C3-8
-Posterior- C6-8

Question 3

Levator Scapulae

Answer 3

*Origin- TVPs C1-C4
*Insertion- Superior medial border of scapula
*Action- Elevates scapula & tilts glenoid inferiorly by downwardly rotating scapula
*Nerve- dorsal scapular nerve

Question 4

Trapezius

Answer 4

*Origin- Medial 1/3 superior nuchal line, external occipital protuberance, SP C7-T12, Nuchal ligament
*Insertion- Posterior border lateral 1/3 of clavicle, acromion, spine of scapula
*Action- Lateral rotation, retraction, elevation/depression of scapula
*Nerve- spinal accessory nerve

Question 5

Erector spinae

Answer 5

*Origin: broad lumbrosacral origin which divides into 3 columns as it extends upwards, each column further dividing into 3 parts.
*Insertion: various (poplar tree)
*Action: extends lsp, tsp, csp and head on neck working together.
Lateral flexion and rotation to the same side
*Innervation: Dorsal Ramus

Question 6

Latissimus Dorsi

Answer 6

*Origin- SP of T7-L5, thoracolumbar fascia, iliac crest, lower 3-4 ribs, inferior angle of scapula
*Insertion- Floor of bicipital groove of humerus
*Action
- Adduction
- Extension
- Medial Rotation
*Nerve- Thoracodorsal nerve C6-8