Muscles of the Back Flashcards
All are innervated segmentally, except the suboccipital triangle
Serratus Posterior Superior
O- N/A
I- N/A
N- Segmentally
A- Elevates ribs 2-4 during inspiration
Serratus Posterior Inferior
O- N/A
I- N/A
N- Segmentally
A- Depresses the inferior most 3 or 4 ribs during inspiration
Splenius Capitus
O- Nuchal ligament and spinous process of upper thoracic vertebrae
I- Mastoid process and superior nuchal line of occipital bone
N- Segmentally by posterior rami
A- Unilaterally: laterally flexes and rotates head and neck to same side.
Bilaterally: extends/ hyperextends the neck
Splenius Cervicis
O- Nuchal ligament and spinous process of uppper thoracic verebrae
I- transverse processes of upper cervical verebrae
N- Segmentally by posterior rami
A- Unilaterally: laterally flexes and rotates head and neck to same side
Bilaterally: extends/ hyperextends neck
Iliocostalis
Part of the Erector Spinae muscles
O- Sacrum, Iliac crest
I- Angle of the ribs
N- Segmentally
A- Extend/laterally bend the verebral column
Longissimus
(Part of the Erector Spinae muscles
O- Sacrum, iliac crest, spinous process of sacrum and inferior lumbar vertebrae
I- Transverse processes of vertebrae, between angle and tubercles of ribs
N- Segmentally
A- Extend/laterally bend vertebral column; extends head
Spinalis
Part of the Erector Spinae muscles
O- Sacrum, iliac crest (small portion), spinous process of sacrum and inferior lumber vertebrae
I- Spinous processes of vertebrae
N- Segmentally
A- Extend/laterally bend the verebral column
Semispinalis
O- Transverse processes of cervical and thoracic vertebrae
I- Occipital bone, spinous processes; spans 4-6 segments
N- Segmentally
A- Extends head and thoracic/cervical region of vertebral column
Multifidus
O- Mainly sacrum and ilium
I- spinous processes; spans 2-4 segments
N- Segmentally
A- Stabalizes vertebrae
Rotatores
O- Transverse processes of vertebrae; most well developed in thoracic region
I- Lamina and spinous process of vertevra 1-2 segments above
N- Segmentally
A- Stabilizes vertebrae
Levator Costarum
O- tips of transverse processes
I- Between tubercle and angle of ribs below
N- segmentally
A- Elevates ribs (assists with inspiration
Rectus Capitus Posterior Major
O-Spinous process of C2 I- Inferior nuchal line of occipital lobe N- Suboccipital nerve A- Unilaterally: rotates head Bilaterally: extends neck
Rectus Capitus Posterior Minor
O- Posterior arch of C1 I- Interior nuchal line of occiptal bone N- Suboccipital nerve A- Unilaterally: rotates head Bilaterally: extends neck
Obliquus Capitus Superior
O- Transverse process of C1
I- Inferior nuchal line of occipital bone
N- Suboccipital nerve
A- Extends neck
Obliquus Capitus Inferior
O- Spinous process of C2 I- Transverse process of C1 N- Suboccipital nerve A- Unilaterally: rotates head Bilaterally: extends neck
