what are the two major groups of musles?
extrinsic back muscles, and intrinsic back muscles
what are the two layers in extrinsic back muscles?
- superficial (trapezius, latissimus dorsi, levator scapulae, rhomboids.
- intermediate ( serratus posterior superior and inferior)
what are intrinsic (deep) back muscles?
- muscles that specifically act on vertebral column, producing movement and maintaining posture
- extend from pelvis to cranium
- innervated by posterior rami of spinal nerves
what are the back muscles in intrinsic back muscles?
- splenius, erector spinae, transversospinalis
what are the 3 posteriors in intermediate extrinsic back muscles?
- serratus posterior is thin, superficial respiratory muscles, has 2 parts
- serratus posterior superior lies deep to rhomboids
- serratus posterior inferior lies deep to latissimus dorsi, both serratus muscles are innervated by intercostal nerves
what is the origin, insertion, action, and innervation of serratus posterior inferior?
what is the origin, insertion, action, and innervation of serratus posterior superior?
What are intrinsic back muscles - superficial, intermediate, and deep layers
- superficial layer (splenius muscles)
- intermediate layer (erector spinae)
Deep layer - transversospinal muscle group (semispinalis, multifidus, rotatores)
What is splenius?
- lies lateral and posterior aspects of neck
- fibers run superolaterally
What is splenius cervicis?
Insertion - transverse process c1-c3
Origin - spinous process of t3-t6
What is splenius capitis?
Insertion - occipital bone and mastoid process of temporal bone
Origin - ligamentum nuchae, spinous process c7-t4
What is splenius function and innervation?
what is splenius function and innervation?
function - acting bilaterally: extend head and neck
- acting unilaterally: laterally flex and rotate
- head and neck
innervation - dorsal rami of spinal nerves
what is the insertion, origin, function, innervation of iliocostalis?
insertion - rib and superior transverse processes
origin - broad tendon from sacrum, iliac crests, and inferior spinous processes
function - acting bilaterally: extend vertebral column and head
- acting bilaterally: laterally flex and vertebral column
innervation - dorsal rami of spinal nerves
what is the insertion, origin, function, innervation of longissimus?
insertion - ribs and superior transverse processes
origin - broad tendon from sacrum, iliac crests, and inferior spinous processes
function - acting bilaterally: extend vertebral column and head
- acting bilaterally: laterally flex and vertebral column
innervation - dorsal rami of spinal nerves
what is the insertion, origin, function, innervation of spinalis?
insertion - superior spinous processes
origin - broad tendon from sacrum, iliac crests, and inferior spinous processes
function - acting bilaterally: extend vertebral column and head
- acting bilaterally: laterally flex and vertebral column
innervation - dorsal rami of spinal nerves
label proper part - iliocostalis thoracis, iliocostalis cervicis, iliocostalis lumborum
label proper part - iliocostalis thoracis, iliocostalis cervicis, iliocostalis capitis, mastoid process
label proper part - spinalis cervicis, spinalis thoracis, semispinalis capitis, semispinalis cervicis, semispinalis thoracis, multifidus
what is insertion and origin for transversospinalis muscle group ?
insertion - spinous process
origin - transverse process
how many segments are semispinalis, multifidis, rotatores?
semispinalis - spans 4-6 segments
multifidis - spans 2-4 segments
rotatores - spans 1-2 segments‹
transversospinalis muscle group function and innervation?
- contralateral rotation
- stabilization
- proprioception
label proper part - semispinalis cervicis, semispinalis capitis, semispinalis thoracis, rotatores, multifidus
what is innvervation of minor deep layer intrinsic back muscles?
dorsal rami of spinal nerves
