Trunk Muscles Flashcards
Iliocostalis (lumborum, thoracis, cervicis)
-origin
common origin
-broad tendon from posterior iliac crest, sacrum, SI ligaments, spinous processes of sacral and inferior lumbar vertebrae
Iliocostalis (lumborum, thoracis, cervicis)
-insertion
I. lumborum -inferior border of angle of ribs 12-6 I. thoracis -all ribs I. cervicis -ribs 6-1 -posterior tubercles of C4-C6
Iliocostalis (lumborum, thoracis, cervicis)
-actions
laterally flex head and vertebral column to same side (ipsilaterally)
bilateral head and trunk extension
Iliocostalis (lumborum, thoracis, cervicis)
-innervation
dorsal rami of cervical, thoracic, and lumbar spinal nerves
longissimus (thoracic, cervicis, capitis)
-origin
common origin
- cervicis and capitis have origins on the transverse processes at lower levels
- this seems like a strange description of the origin; will try and figure out from book
longissimus (thoracic, cervicis, capitis)
-insertion
L. thoracis
-tips of transverse processes T1-T12
-tubercles of inferior border of ribs 9 and 10
L. cervicis
-superior thoracic transverse processes to cervical transverse processes
L capitis
-arises with L. cervicis and attaches to mastoid process
longissimus (thoracic, cervicis, capitis)
-actions
ipsilateral lateral flexion of head and vertebral column
bilateral head and trunk extension
L.capitis
-rotates head to same side
longissimus (thoracic, cervicis, capitis)
-innervation
dorsal rami of cervical, thoracic, and lumbar spinal nerves
Spinalis (thoracic, cervicis)
-origin
common origin
-from spinous processes
Spinalis (thoracic, cervicis)
-insertion
S. thoracic
-tips of spinous processes of thoracic vertebrae
S. cervicis
-ligamentum nuchae to axis (C2)
*these are inconsistent attachments according to the notes
Spinalis (thoracic, cervicis)
-actions
head and vertebral column extension
Spinalis (thoracic, cervicis)
-innervation
dorsal rami of cervical, thoracic, and lumbar spinal nerves
semispinalis (thoracis, cervicis, capitis)
-origin
S. thoracis
-transverse processes superomedially T6-T10
S. cervicis
-transverse processes superomedially T1-T6
S. capitis
-transverse processes T1-T6 (C7 articular process)
semispinalis (thoracis, cervicis, capitis)
-insertion
S. thoracis -spinous processes C6-T4 S. cervicis -Spinous processes C2-C5 S. Capitis -Inferior to superior nuchal line
semispinalis (thoracis, cervicis, capitis)
-actions
all -contralateral trunk/head rotation S. thoracis and cervicis -vertebral column extension S. capitis -head extensor when active bilaterally
semispinalis (thoracis, cervicis, capitis)
-innervation
dorsal rami of cervical, thoracic, and lumbar spinal nerves
multifidus
-origin
laminae (mamillary process) of S4-C2, including zygapophysial capsule
may be absent in thoracic region
multifidus
-insertion
superomedially 2-4 vertebrae to spinous process
multifidus
-action
unilaterally -lateral flexion of vertebral column -contralateral transverse rotation bilaterally -trunk extension vertebral column stabilization
multifidus
-innervation
dorsal rami of cervical, thoracic, and lumbar spinal nerves
rotatores (brevis and longus)
-origin
transverse processes of entire vertebral column
rotatores (brevis and longus)
-insertion
superomedially to spinous processes of next (brevis) or 2nd SP (longus)
rotatores (brevis and longus)
-actions
- contralaterally rotate superior vertebrae
- bilaterally stabilize superior vertebrae
rotatores (brevis and longus)
-innervation
dorsal rami of cervical, thoracic, and lumbar spinal nerves
splenius (cervicis, capitis)
-origin
S. cervicis -spinous processes of T3-T6 S. capitis -spinous processes of C7-T4 -ligamentum nuchae
splenius (cervicis, capitis)
-insertion
S. cervicis -transverse processes of C2-C5 S. capitis -lateral part of superior nuchal line -mastoid process
splenius (cervicis, capitis)
-actions
bilateral contraction
-extension of cervical region
unilateral contraction
-ipsilateral lateral flexion and rotation
splenius (cervicis, capitis)
-innervation
S. cervicis
-dorsal rami of spinal nerves C4-C8
S. capitis
-dorsal rami of spinal nerves C3-C5
Levator costarum (intertransversarii of thoracic region) -origin
tip of thoracic transverse process
Levator costarum (intertransversarii of thoracic region) -insertion
inferolaterally to angle of inferior adjacent rib
Levator costarum (intertransversarii of thoracic region) -actions
- elevate ribs during inspiration
- proposed to be involved in lateral flexion
Levator costarum (intertransversarii of thoracic region) -innervation
ventral rami of thoracic spinal nerves
quadratus lumborum
-origin
- iliolumbar ligament
- internal lip of iliac crest
quadratus lumborum
-insertion
- tips of lumbar transverse processes
- inferior border of rib 12
quadratus lumborum
-actions
- vertebral column extension
- vertebral column lateral flexion
- fixes rib 12 during inspiration
quadratus lumborum
-innervation
branches of ventral rami of T12, L1-3(4)
psoas major
-origin
- transverse process of lumbar vertebrae
- sides of vertebral body of T12, L1-L5
- intervertebral discs
psoas major
-insertion
lesser trochanter of femur
psoas major
-actions
- increase lumbar lordosis
- assist in vertebral column lateral flexion
- hip flexion
- pelvis flexion on trunk
psoas major
-innervation
- lumbar plexis
- branches of primary ventral rami L1-L4
rectus abdominis
-origin
pubic crest and symphysis
rectus abdominis
-insertion
costal cartilages 5-7
xyphoid process
rectus abdominis
-actions
trunk flexion
rectus abdominis
-innervation
ventral rami of spinal nerves T5-T12
external abdominal oblique
-origin
anterior fibers
-external surface of ribs 5-8
lateral fibers
-external surface of ribs 9-12
external abdominal oblique
-insertion
- outer lip of iliac crest
- linea alba via aponeurosis
external abdominal oblique
-actions
bilaterally -trunk flexion -lateral fibers act on lumbar region to tilt pelvis posteriorly unilaterally -contralateral transverse rotation compress abdomen
external abdominal oblique
-innervation
ventral rami of spinal nerves T5-T12
internal abdominal oblique
-origin
- lateral 2/3 of inguinal ligament
- iliac crest
- thoracolumbar fascia
internal abdominal oblique
-insertion
- crest of pubis
- pectineal line
- linea alba
internal abdominal oblique
-actions
upper anterior fibers
-trunk flexion
unilaterally
-work with contralateral external obliques to rotate trunk (for the internal obliques this is ipsilateral transverse rotation)
internal abdominal oblique
-innervation
ventral rami of spinal nerves T7-T12
iliohypogastric and ilioinguinal nerves
transverse abdominis
-origin
- lower 6 ribs
- thoracolumbar fascia (attached to transverse processes of lumbar vertebrae
- iliac crest
- inguinal ligament
transverse abdominis
-insertion
- linea alba
- pubic crest
transverse abdominis
-actions
- trunk stabilization via fixation of linae alba
- compress abdomen
transverse abdominis
-innervation
- ventral rami of spinal nerves T7-T12
- iliohypogastric and ilioinguinal nerves
