Erector Spinae Muscles

Question 1

Iliocostalis Lumborum

Answer 1

O: Iliac crest, sacrum

I: lower borders of lower 6-7 ribs

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

In: dorsal rami of spinal nerves

Question 2

Iliocostalis Thoracis

Answer 2

O: upper borders of lower 6-7 ribs

I: lower borders of upper 6-7 ribs

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

In: dorsal rami of spinal nerves

Question 3

Iliocostalis Cervicis

Answer 3

O: upper borders of upper 6-7 ribs

I: transverse processes of 4th-6th cervical vertebrae

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

In: dorsal rami of spinal nerves

Question 4

Longissimus Thoracis

Answer 4

O: intermediate part of common tendon

I: lower 9 or 10 ribs + adjacent transverse processes of vertebrae

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

In: dorsal rami of spinal nerves

Question 5

Longissimus Cervicis

Answer 5

O: transverse processes of upper 4th-6th thoracic vertebrae

I: transverse processes of 2nd - 6th cervical vertebrae

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

In: dorsal rami of spinal nerves

Question 6

Longissimus Capitis

Answer 6

O: tendons of origin of longissimus cervicis + articular processes of the lower 4 cervical vertebrae

I: mastoid process of the skull

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

In: dorsal rami of spinal nerves

Question 7

Spinalis Thoracis

Answer 7

O: spinous processes of T11 - L2 vertebrae

I: spinous processes of upper thoracic vertebrae (T4-T8)

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

In: dorsal rami of spinal nerves

Question 8

Spinalis Cervicis

Answer 8

O: ligamentum nuchae + spinous processes of C7 - T1 or T2

I: spinous processes of axis (C2), possibly C3-C4)

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

In: dorsal rami of spinal nerves

Question 9

Spinalis Capitus

Answer 9

Considered the medial part of semispinalis capitus

Question 10

Semispinalis Cervicis

Answer 10

O: transverse processes of T1 - T5/T6

I: spinous processes of second - fifth cervical vertebrae

A: extension of vertebral column

In: dorsal rami of cervical and thoracic spinal nerves

Question 11

Semispinalis Capitis

Answer 11

O: transverse processes of T1 - T6/T7 + articular processes of C5 - C7

I: Occipital bone (between superior and inferior nuchal lines)

A: extension of the head

In: dorsal rami of the cervical and thoracic spinal nerves

Question 12

Splenius Capitus

Answer 12

O: ligamentum nuchae + spinous processes of C7 - T3/T4

I: mastoid process and occipital bone of skull

A: rotation of head and cervical vertebral column to same side (unilaterally) + extension of head (bilaterally)

In: dorsal rami of middle cervical spinal nerves

Question 13

Splenius Cervicus

Answer 13

O: spinous processes of T3 - T6

I: transverse processes of upper two to four cervical vertebrae

A: rotation of head and cervical vertebral column to same side (unilaterally) + extension of head (bilaterally)

In: dorsal rami of middle cervical spinal nerves