KH 2220Laura Abbott, MS, LMT

Day 8Muscles of the Spine:Spinalis, Longissimus,Iliocostalis, Multifidus, Rotatores

Erector Spinae - Spinalis This is the narrow medial

column of the erector spinae muscle and is relatively insignificant.

It arises from the common origin and extends from the spinous processes in the superior lumbar and inferior thoracic regions to the spinous processes in the superior thoracic region.

It may also be divided into three parts (spinalis thoracis, spinalis cervicis, and spinalis capitis).

Erector Spinae - Longissimus This is the intermediate

column of the erector spinae muscle and it arises from the common origin and is attached to the transverse processes of the thoracic and cervical vertebrae, and the mastoid process of the temporal bone of the skull.

This gives this muscle a herringbone appearance.

The longissimus can also be divided into three parts according to the regions it traverses.

Longissimus thoracis inserts into the tips of the transverse processes of all of the thoracic vertebrae, and into the tubercles of the inferior nine to ten ribs; longissimus cervicis extends from the superior thoracic transverse processes to the cervical transverse processes; the longissimus capitis arises in common with the cervical part and attaches to the mastoid process of the temporal bone.

Longissimus

Erector Spinae - Iliocostalis This is the lateral column

of the erector spinae and it arises from the common origin and inserts into the angles of the ribs.

It may be divided into three parts according to the region involved.

Iliocostalis lumborum is attached to the inferior six ribs; iliocostalis thoracis is attached to all the ribs; and iliocostalis cervicis is attached to the superior six ribs and the posterior tubercles of C4 to C6 vertebrae.

ILikeSpaghetti

IliocostalisLongissimu

sSpinalis

Actions of the Erector Spinae Acting bilaterally, all three columns of the erector

spinae extend the head and part or all of the vertebral column.

Acting unilaterally, the erector spinae laterally flexes the head or the vertebral column.

In addition, the longissimus capitis muscle rotates the head so that it is turned to the same side.

The erector spinae muscles are the chief controller of flexors of the vertebral column.

They straighten the flexed column and can bend it posteriorly. They also "pay out" (release) during its flexion so that the movement is slow and controlled.

Multifidus O: Transverse process

of one vertebrae I: spinous process of

all vertebrae extending from 2-4 vertebrae higher

A: bilaterally extends vertebral column; unilaterally rotate vertebral bodies (column) to opposite side and lateral flexion to same side

RotatoresO: transverse

process of one vertebra

I: spinous process of vertebra 1-2 above

A: rotate to opposite side; bilateral extension