Anatomy Deep Back Muscles

Where does Intertransversarii attach?

Transverse process of adjacent vertebrae

Where does Levatores costarum attach?

Transverse processes C7-T11, and the fibers run inferolaterally to attach to rib below

Rotatores muscles: -Location What are the 2 subdivisions? What is the Origin and Insertion?

Deepest of transversospinalis group -In thoracic level -Stabilization Two subdivisions: Rotatores longus: 2 vertebral levels O: attaches to transverse process of one vertebrae I: spinous process of a vertebrae 2 levels higher Rotatores Brevis: 1 vertebral level O: attaches to transverse process of one vertebrae I: spinous process of vertebrae above it. Lies in transverse plane

Transversospinalis muscle group. -Subdivisons -Origin -Insertion -Action

Divisions: rotatares, multifidis, semispinalis (deep group of muscles of the deep back muscle group ) O: transverse processes I: spinous processes A: Stabilizing vertebrae, assist in extension and rotation

Deep back muscle vasculature

Dorsal branch of posterior intercostal arteries (which branches from aorta)

Splenius Cervicis Insertion Action

I: Posterior tubercles of transverse processes of C1-3 vertebrae Action: Bilaterally: Extend neck Unilaterally: Flexes and rotates neck to same side *Makes sense cervicis involved with neck movement because of name

Segmental back muscles -Subdivisons -Function

Interspinales, Intertransversaraii, Levatores Costarum -Deepest of the deep back muscles -Attach adjacent vertebral levels to stabilize vertebral column

Where does interspinales attach?

Spinous processes of adjacent vertebrae (Segmental muscle)

Semispinalis Thoracis a) What muscle group is it part of? b) Origin and Insertion

- Transversospinalis muscle group -O: transverse processes of T6-T10 inferiorly -I: spinous process of C5-T4 superiorly

Multifidus -Location -Length -Where is it most pronounced? -Action

-Lie deep to semispinalis muscles -Span 2-4 vertebrae -In lumbar region -Acts as stabilized of vertebral column NOT as an extensor/rotator

Longissimus -Location -Origin -Insertion

-Medial to iliocostalis, lateral to spinalis I: Ribs between tubercles, Transverse process of vertebrae and mastoid processes temporal bone

Iliocostalis -Location -Origin -Insertion -Subdivisions

-Most lateral (farthest from rib) of erector spinae muscles -O: Common tendon of erector spinae or lower ribs inferiorly -I: Angle of the ribs and transverse processes of lower cervical vertebrae -Iliocostalis lumborum, Iliocostalis Thoracis, Iliocostalis Cervicis

Semispinalis a) Location b) Length c) Action d) Subdivisions

-Most superficial muscles of the transversospinalis group. -Subdivided based on region(Thoracic, Cervicis, Capitus) - Span 4-6 vertebral levels -Action: Bilateral: Extension of back Unilateral: Rotation of torso in OPPOSITE direction

Splenius Muscles -Divisions -Origin -Action -Innervation

-Splenius capitus, Splenius cervicis -Lie deep to trapezius, deep and medial to levator scapulae -O: Ligamentum nuchae and spinous processes of C7-T6 vertebrae -Acting with opposite partners, they extend the head and neck (bilaterally) and rotate head and neck (unilaterally) to side of contraction

Erector Spinae Muscles -Subdivisions -Length -Origin -Insertion -Action (Bilaterally, unilaterally)

-iliocostalis, longissimus, spinalis -largest group of muscles of the deep back muscle group -Span 6-10 vertebral levels -O: Common tendon attached to spinous processes of inferior lumbar vertebrae, posterior sacrum, iliac crest, and sacroiliac ligaments -I: Subdivisons attach to different regions (lumborum, thoracic, cervicis, capitus) -Actions: Bilaterally: Extensors of back (and head) Unilaterally: Laterally flex the back (and head)

Spinalis:

Most medial of erector spinae muscles I: Attaches to spinous process in the upper thoracic region and midcervical region and the skull -Subdivisions: Thoracis, Cervicis, Capitus

Splenius Capitus Insertion Action

Most superior of splenius muscle I: Mastoid process of temporal bone and lateral 1/3 of superior nuchal line of occipital bone A: Bilaterally: Extend head posteriorly Unilaterally: Rotates head to SAME SIDE *makes sense that capitus involved in head movement because of the name

Semispinalis Cervices a) What muscle group is it part of? b) Origin and Insertion

a) Transversospinalis muscle group O: transverse processes of T1-T6 inferiorly I: spinous process of C2-C5 superiorly *Above the semispinalis thoracis and below the semispinalis capitus

Semispinalis Capitus a) What muscle group is it part of? b) Origin and Insertion

a) Transversospinalis, and the most superficial of semispinalis subdivision *indistinguishable from the spinalis capitus) O: transverse process of T1-T6 and articular process of C4-C7 I: occipital bone between inferior and superior nuchal lines