Muscles Of The Trunk Flashcards
Iliocostalis Lumborum
O: broad tendon from posterior iliac crest, sacrum, SI processes of sacral and inf. lumbar vertebrae
I: Inf. border of angle of ribs 12-6
A: laterally flexes head and vertebral column to same side;
Bilateral activation- extensions of head and trunk
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Iliocostalis Thoracis
O: common broad tendon origin; from post. iliac crest, sacrum, SI ligaments, spinous process of sacral/lumbar vertebrae
I: all of the ribs
A: laterally flex head and vert. column to same side
Bilateral activation- extensors of head and trunk
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Iliocostalis Cervicis
O: common broad tendon from post. Iliac crest, sacrum, SI ligaments, spinous processes of sacral and Inf. Lumbar vertebrae
I: superior 6 ribs and post. Tubercles of C4-C6
A: laterally flex head and VC to same side
Bilateral activation- extensors of head and trunk
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Longissimus Thoracis
O: common origin (broad tendon from PI crest, sacrum, SI ligaments, spinous processes)
I: tips of transverse processes T1-T12 and tubercles of Inf. Border of ribs 9,10
A: lat. flex head and vert. Column to same side
Bilateral activation- extensors of head and trunk
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Longissimus Cervicis
O: common origin (broad tendon from PI crest, sacrum, SI ligaments, spinous processes of sacral and Inf lumbar vertebrae); also, have origins on the transverse processes at lower levels
I: sup. Thoracis transverse processes to cervical transverse processes
A: lat. flex head and vert. Column to same side
bilateral activation- ext. of head and trunk
N: dorsal rami of cervical, thoracic, and lumbar nerves
Longissimus Capitis
O: common origin (broad tendon from PI crest, sacrum, SI ligaments, spinous processes of sacral and Inf. Lumbar vertebrae; also have origins on the transverse processes at lower levels
I: arises with L. Cervicis and attaches to mastoid process
A: Lat. flex head and VC to same side
Bilateral activation- ext of head and trunk;
Also rotates head to same side
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Spinalis Thoracis
O: common origin; from spinous processes of sacral and Inf. Lumbar vertebrae
I: Tips of spinous processes of thoracic vert
A: extensors of VC and head
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Spinalis Cervicis
O: common origin; from spinous processes
I: Ligamentum Nuchae to axis
A: extensors of VC; also head
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Semispinalis Thoracis
O: transverse processes superomedially T6-10
I: spinous processes T1-T4, C6-7
A: extensors of VC
Unilateral- rotates trunk to opposite side
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Semispinalis Cervicis
O: Transverse processes superomedially T1-T6
I: spinous processes C2-C5
A: extensors of VC
Unilateral- rotates trunk/head to opposite side
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Semispinalis Capitis
O: transverse processes T1-T6 (C7 articular process)
I: inferior to superior Nuchal line
A: extensor of head
Unilateral- rotates head to opposite side
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Multifidus
O: laminae (mammillary process) of S4-C2, including zygapophysial capsule; may be absent in thoracic region
I: superomedially 2-4 vertebrae to SP
A: unilateral- lateral flexion of VC and opposite rotation
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Rotatores Brevis
O: transverse processes of entire VC
I: superomedially to SP of next spinous process
A: rotates superior vertebrae to opposite side;
Bilaterally stabilizes superior vertebrae
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Rotatores Longus
O: TP of entire VC
I: superomedially to SP of 2nd spinous process
A: rotates superior vert. To opposite side
Bilaterally- stabilizes superior vert.
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves
Splenius Cervicis
O: SP of T3-T6
I: TP of C2-5
A: bilateral- extension of cervical region
Unilateral- Lat. flexion and rotation to same side
N: dorsal rami of spinal nerves C4-C8
Splenius Capitis
O: SP of C7-T4 and Ligamentum Nuchae
I: lateral part of superior Nuchal line and mastoid process
A: bilateral- extension of cervical region
Unilateral- lateral flexion and rotation to same side
N: dorsal rami of spinal nerves C3-C5
Levanter Costarum
O: tip of thoracic TP
I: inferolaterally to angle of inferior adjacent rib
A: elevates ribs during inspiration; may help in lateral flexion
N: ventral rami of thoracic spinal nerves
Quadratus Lumborum
O: iliolumbar ligament and internal lip of iliac crest
I: tips of lumbar TP, inferior border of rib 12
A: extension and lateral flexion of VC; fixes rib 12 during inspiration
N: branches of ventral rami of T12, L1-3(4)
Psoas Major
O:TP of lumbar vertebrae, sides of body (T12, L1-5, and IV discs)
I: Lesser trochanter of femur
A: Increases lumbar lordosis, assists in lat. flexion, flexes hip/pelvis on trunk
N: lumbar plexus, ranches of primary ventral rami
Rectus Abdominis
O: pubic crest and symphysis
I: costal cartilages 5-7 and xyphoid process
A: flexion of trunk
N: ventral rami of spinal nerves T5-12
External Abdominal Oblique
O: ext. surface of ribs 5-8 (ant fibers) and ribs 9-12 (lat fibers)
I: outer lip of iliac crest, linea alba via aponeurosis
A: bilat- flexes trunk; lat fibers act on lumbarregion to tilt pelvis posteriorly
unilat- rotates to opp. side; compresses abdomen
N: ventral rami of spinal nerves; T5-12
Internal Abdominal Oblique
O: lat. 2/3 of inguinal ligament; iliac crest; thoracolumbar fascia
I: crest of pubis, pectineal line, linea alba
A: upper ant. fibers flex trunk; unilat-work ext. oblique of opp. side to rotate trunk
N: ventral rami of spinal nerves T7-12; iliohypogastric and iliolinguinal nn
Transverse Abdominis
O: lower 6 ribs, thoracolumbar fascia (attached to TP of lumbar vert), iliac crest, ing. ligament
I: linea alba, pubic crest
A: stabilize trunk via fixation of linea alba; compresses abdomen
N: ventral rami of spinal nerves T7012; iliohypogastric and iliolinguinal n
Obliquus Capitis Superior
O: TP of C1
I: occipital bone deep to S. capitis and cervicis and superficial to R. capitis post. major and minor
A: rotation at AA joint; extension of AO; a bit of lateral flexion
N: dorsal rami of C1
