Neck muscle rotatores

Question 1

Semispinalis cervicis

Answer 1

Origin:
transverse process (T1-T6)

Insertion:
spinous process C2-C6

Direction:
Upwards and inwards

Action:

• unilateral action - contralateral rotation
• Bilateral action - trunk extension

Nerve supply:
adjacent posterior primary rami

Question 2

Multifidus

Answer 2

Origin:

• Sacrum
• Fascia overlying the erector spinae muscles
• All transverse processes

Insertion:
spinous processes C2-L5

Direction:
up and in

Action:

• unilateral action- contralateral rotation
• Bilateral action- trunk extension
• stabilisation

Nerve supply:
adjacent posterior primary rami

Question 3

Scalenus anterior

Answer 3

Origin:
transverse process of cervical spine

Insertion:
1st rib

Direction:
Downwards and laterally

Action:

• Bilateral action- neck flexion
• unilateral action - ipsilateral lateral flexion and contralateral rotation

Nerve supply:
ventral rami cervical spine (C30C8)

Question 4

Splenius cervicis

Answer 4

Origin:
upper spinous processes of C3-C6)

Insertion - transverse processes of C1-C4

Direction:
upwards

Action:

• bilateral action - neck extension
• unilateral action - ipsilateral lateral flexion and rotation

Nerve supply:
dorsal rami C5,6,7

Question 5

Splenius capitis

Answer 5

Origin:

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

I:
mastoid process and lateral 1/3 superior nuchal line

Direction:
upwards

Action:

• bilateral action - neck extension
• unilateral action - ipsilateral lateral flexion and rotation

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

Question 6

Sternocleidomastoid

Answer 6

Origin:

• twhio heads:
• lateral 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 7

Obliquus capitis inferior

Answer 7

Origin:
C2 spinous process

Insertion:
C1 transverse process

Action:

• ipsilateral action- rotation
• bilateral action -extends the head

Nerve supply:
Dorsal rami (C1)

Question 8

Rectus capitis posterior major

Answer 8

Origin:
C2

Insertion:
The skulll

Action:

• ipsilateral action - rotation
• Bilateral action - extends the head

Nerve supply:
Dorsal rami (C1)