Transversospinalis Muscles

Question 1

Semispinalis Thoracis

Answer 1

O: transverse processes of lower 6 thoracic vertebrae (T7 - T12)

I: spinous processes of lower two cervical and upper 4 thoracic vertebrae (C6 - T4)

A: extension of the vertebral column (bilateral action) / lateral flexion AND rotation (unilateral action)

In: dorsal rami of cervical and thoracic nerves

Question 2

Semispinalis Cervicis

Answer 2

O: transverse processes of T1 - T5 or T6

I: spinous processes of C2 - C5

A: extension of the vertebral column

In: dorsal rami of cervical and thoracic nerves

Question 3

Semispinalis Capitis

Answer 3

O: transverse processes of T1 - T5 or T6 + articular processes of C5 - C7

I: occipital bone between superior/inferior nuchal lines

A: extension of the head

In: dorsal rami of cervical and thoracic nerves

Question 4

Multifidi

Answer 4

O: sacrum + transverse processes of lumbar through cervical vertebrae

I: spinous processes of C2 - L5 (spanning 2-4 segments at a time)

A: extension, lateral flexion, and opposite rotation of vertebral column

In: dorsal rami of spinal nerves

Question 5

Rotatores

Answer 5

O: sacrum + transverse processes of lumbar through cervical vertebrae

I: spinous processes of C2 - L5 (spanning 1 segment at a time)

A: extension, lateral flexion, and opposite rotation of vertebral column

In: dorsal rami of spinal nerves