Neck muscle lateral flexors

Question 1

Levator scapulae

Answer 1

Origin:
transverse processes of C1-C3/4

Insertion:
medial border of scaoula between superior angle and base of spine

Action:

• elevates and medially rotates and retracts scapula
• extends and laterally flexes the neck

Nerve supply:

• ventral rami (C3,4)
• Dorsal scapula nerve (C5)

Question 2

Sternocleidomastoid

Answer 2

Origin:
Two heads-
Sternal head - upper surface of manubrium
Clavicular head - upper surface of medial 1/3 of the clavicle

Insertion:
Mastoid process of the skull

Direction:
Upwards

Action:

• Assists with resperation
• Bilateral action - neck flexion
• Unilateral action - ipsilateral lateral flexion and contralateral rotation

Nerve supply:

• Motor- spinal part of accessory nerve (cranial nerve 11)
• Sensory - ventral rami (C2,3)

Question 3

Splenius capitis

Answer 3

Origin:

• spinous processes (T4-C7)
• Lower half of ligamentum nuchae

Insertion:
Mastoid process and lateral 1/3 superior nuchal line

Direction:
Upwards

Action:
-Bilateral action - neck flexion -
Unilateral action- ipsilateral lateral flexion and rotation

Nerve supply:
Dorsal rami (C3,4,5)

Question 4

Upper trapezius

Answer 4

Origin:

• extensive medial attachment from the base of the medial 1/3 of the superior nuchal line and the occipital bone
• ligamentum nuchae
• spinous processes of C7 to T12 and the intervening supraspinous ligament.

Insertion:
posterior border of the lateral 1/3 of the clavicle

Direction:
Down and laterally

Action:
elevation, retraction and lateral rotation of the scapula

Nerve supply:

• Motor - spinal part of cranial nerve
• Sensory- ventral rami C3,4

Question 5

Iliocostalis thoracics

Answer 5

Origin:

• iliac crest and tuberosity
• Sacrum
• spinous processes of t11-l5 and supraspinous ligaments

Insertion:
posterior tubercles of the transverse processes C4-C7

Direction:
up and out via slips

Action:

• unilateral action- ipsilateral side flexion/rotation
• bilateral action - trunk/neck extension

Nerve supply:
adjacent posterior primary rami

Question 6

Rectus capitis lateralis

Answer 6

Origin:
transverse processes of atlas

Insertion:
jugular processes of occipital bone

Direction:

Action:
laterally flexes the neck

Nerve supply:
ventral rami (C1,2)

Question 7

Scalenus anterior, medius and posterior

Answer 7

Origin:
transverse processess of cervical spine

Insertion:

• anterior and middle scalenus - 1st rib
• posterior scalenus - 2nd rib

Direction:
Downwards and laterally

Action:
-all assist with reperation
anterior scalenus:
-bilateral action -neck flexion
-unilatreral action - ipsilateral lateral flexion and contralateral rotation
Middle and posterior scalenus:
-unilateral action - ipsilateral lateral flexion

Nerve supply:
ventral rami cervical spine (C3-C8)

Question 8

Longissimus cervicis

Answer 8

Origin:
transverse processes T1-T6

Insertion:
posterior tubercles of transverse processes C2-C6

Direction:
up and out

Action:

• Unilateral action - ipsilateral side flexion/rotation
• bilateral action- trunk/extension

Nerve supply:
adjacent posterior primary rami

Question 9

Spinalis cervicis

Answer 9

Origin and insertion:
spinous processes to spinous processes

Direction:
upwards

Action:

• unilateral action- ipsilateral side flexion/rotation
• bilateral action- trunk extension

Nerve supply:
adjacent posterior primary rami