Intrinsic back Muscles

Question 1

1. Splenius Capitis
2. Splenius Cervicis

Identify and Describe the attachments, function, innervation

Answer 1

Are the most superficial of all the Intrinsic Back Muscles

Deep to the levator muscle

and superficial to the erector spinae group

Splenius capitis

O: Lower half of ligamentum nuchae, spinous processes of CVII to TIV

I: Mastoid process, skull below lateral one third of superior nuchal line

Nerve Supply:

Posterior rami of middle cervical nerves

Action:

Together—draw head backward, extending neck;

individually—draw and rotate head to one side

(turn face to same side)

Splenius cervicis

O: Spinous processes of TIII to TVI

I: Transverse processes of CI to CIII

Nerve:

Posterior rami of lower cervical nerves

Together—extend neck;

individually—draw and rotate head to one side (turn face to same side)

Question 2

ligamentum nuchae

Answer 2

The ligamentum nuchae is that well-developed portion of the supraspinous ligament in the cervical region. It runs from the external occipital protuberance along the tips of the spinous processes of the cervical vertebrae, to the tip of the spinous process of the vertebra prominens (usually C7)

Question 3

Transversospinales group

Semispinalis

• Capitis
• Thoracis
• Cervicis

Answer 3

Transversospinales group of back muscles

SEMISPINALIS

• • Unique: has attachments in thoracis to the skull.*
• • (the splenis attaches to the mastoid process of the skull, semispinalis attaches on either side of the nuchal line*

Semispinalis thoracis

Origin:

Transverse processes of TVI to TX

Insertion:

Spinous processes of upper four thoracic and lower two cervical vertebrae

Semispinalis cervicis

Origin:

-Transverse processes of upper five or six thoracic vertebrae

Insertion:

Spinous processes of CII (axis) to CV

Semispinalis capitis

Origin:

Transverse processes of TI to TVI (or TVII) and CVII and articular processes of CIV to CVI Medial area between the superior and inferior nuchal lines of occipital bone

Question 4

Multifidus

Answer 4

Multifidus

Origin:

Sacrum, origin of erector spinae, posterior superior iliac spine, mammillary processes of lumbar vertebrae, transverse processes of thoracic vertebrae, and articular processes of lower four cervical vertebrae

Insertion:

Base of spinous processes of all vertebrae from LV to CII (axis)

Question 6

Iliocostalis

• lumborum
• thorcacis
• cervicis

Answer 6

Iliocostalis lumborum

Origin:

Sacrum, spinous processes of lumbar and lower two thoracic vertebrae and their supraspinous ligaments, and the iliac crest

Insert:

Angles of the lower six or seven ribs

Iliocostalis thoracis

Origin:

-Angles of the lower six ribs

Insertion:

• Angles of the upper six ribs and the transverse process of CVII

Iliocostalis cervicis

Origin:

-Angles of ribs III to VI

Insertion:

-Transverse processes of CIV to CVI

Question 7

Longissimus

• Thoracis
• Cervicis
• Capitis

Answer 7

LONGISSIMUS MUSCLE

Unique: has attachments in the transverse processes from the sacrum to transverse processes along the spinal column

Longissimus thoracis

ORIGIN:

Blends with iliocostalis in lumbar region and is attached to transverse processes of lumbar vertebrae

INSERTION:

Transverse processes of all thoracic vertebrae and just lateral to the tubercles of the lower nine or ten ribs

Longissimus cervicis

Transverse processes of upper four or five thoracic vertebrae Transverse processes of CII to CVI

Longissimus capitis

Origin:

Transverse processes of upper four or five thoracic vertebrae and articular processes of lower three or four cervical vertebrae Insertion:

Posterior margin of the mastoid process

Question 8

Spinalis

• thoracis
• cervicis
• capitis

Answer 8

Spinalis thoracis

Origin:

Spinous processes of TX or TXI to LII

Insertion:

Spinous processes of TI to TVIII (varies)

Spinalis cervicis

Origin:

Lower part of ligamentum nuchae and spinous process of CVII (sometimes TI to TII)

Insertion:

Spinous process of CII (axis)

Spinalis capitis

Origin

Usually blends with semispinalis capitis

Insertion:

With semispinalis capitis

The middle or intermediate column is the longissimus, which is the largest of the erector spinae subdivision extending from the common tendon of origin to the base of the skull. Throughout this vast expanse, the lateral positioning of the longissimus muscle is in the area of the transverse processes of the various vertebrae.

Question 9

Rotatores

Thoracis

Cervicis

Answer 9

ROTATORES - are deep muscle of the back,

mostly in the thoracic and cervical spine.

Rotatores lumborum

Origin:

Transverse processes of lumbar vertebrae

Insertion:

Spinous processes of lumbar vertebrae

Rotatores thoracis

Origin:

Transverse processes of thoracic vertebrae

Insertion:

Spinous processes of thoracic vertebrae

Rotatores cervicis

Origin

Articular processes of cervical vertebrae

Insertion

Spinous processes of cervical vertebrae