Back Muscles Flashcards
Upper Trapezuis
O: external occipital protruberence, med 1/3 of superior nuchal line, ligamentum nuchae, spinous process of C7
I: lateral 1/3 of clavicle
N: Spinal Accessory Nerve (CN XI)
A: elevates scapula and shoulder, *up rot of scap w/ middle trap
Bi> capital and cervical extension
Un> rot to opposite side, lat flex to same side
Middle Trapezuis
O: spinous process T1-T5
I: acromion, spine of scapula and crest of upper lip
N: Spinal Accessory (CN XI)
A: scapular adduction
Lower Trapezius
O: spinous process T6-T12
I: spine of scapula
N: C3 & C4 (contribution from CN XI)
A: scapular adduction, depression, and upward rotation
Latissimus Dorsi
O: spinous process of T6-T12, spinous processes of lumbar and sacral vertebrae via thoracolumbar fascia, ribs 9-12, iliac crest
I: floor of intertubecular ffroove
N: thoracodorsal nerve (C6-C8)
A: extends, adducts, medially rotates humerus, elevates trunk towards arms, anterior pelvic tilt
Levator Scapula
O: posterior tubercles of trans process of C1-C4
I: med. border of scapula, superior to root of spine
N: dorsal scapular nerve, and C3-C4
A: elevates/ adducts scapula, downward rotation of scapula, flexion and rotation to same side, assists cervical extension
Rhomboid Major
O: spinous process of T2-T5
I: med. border of scapula from spine to inferior angle
N: dorsal scapular never
A: scapular adduction, elevation and downward rotation
Rhomboid Minor
O: Ligamentum nucha, spinous process C7-T1
I: root of spine of scapula
N: dorsal scapular nerve
A: scapular adduction, elevation and downward rotation
Serratus Posterior Superior
O: inferior part of ligamentum nuchae and spinous process of C7 and T1-T3
I: ribs 2-5
N: ventral rami T2-T5
A: lifts ribs-increases diameter of thorax and raises sternum
Serratus Posterior Inferior
O: spinous process T11, T12, L1, L2 via thoracolumbar fascia
I:ribs 9-12
N: ventral rami T9-T12
A: depresses lower ribs
Splenius Capitis
O: ligamentum nuchae at C3-C7 and spinous process of C7-T4
I: mastoid process and occipital bone inferior to the lateral 1/3 of the superior nuchal line
N: dorsal rami C1, C2 and C3-C6
A: bi> capital extension
un> lateral bending of head to same side, rot of head to same side
Splenius Cervicis
O: spinous process T3-T6
I: transverse process of C1-C3
N: dorsal rami C4-C8
A: ext of cervical spine (bilateral), rotation and lateral bending of cervical spine to same side (unilateral)
Iliocostalis Lumborum
O: posterior sacrum, iliac crest, spinous process of T12, L1-L5, supraspinous, sacrotuberous, and sacroiliac ligaments
I: transverse processes of all lumbar vertebrae , inferior 6 ribs
Ilicostalis Thoracis
O: ribs 7-12
I: upper 6 ribs and trans process of C7
Iliocostalis Cervicis
O: ribs 3-6
I: posterior tubercles of trans process C4-C6
Longissimus Thoracis
O: common origin, trans and accessory processes of L1-L5, thoracolumbar fascia
I: trans process of all thoracic vertebrae and ribs 9-12
Longissimus Cervicis
O:trans process T1-T5
I: posterior tubercles of trans process of C2-C6
Longissimus Capitis
O:trans processes of T1-T5, articular processes of C4-C7
I: mastoid process
*rot head to same side
Spinalis Thoracis
O: spinous processes T11, T12, L1, L2
I: spinous process T1-T4
Spinalis Cervicis
O: ligamentum nuchae, spinous process of C6, C7 and sometimes T1-T2
I: spinous process of axis and spinous processes of C3-C4
Spinalis Capitis
O: spinous process C5-C7, and T1-T3
I: occiput b/t superior and inferior nuchal lines
Erector Spinae Innervation and Action
N: dorsal rami of most spinal nerves
A: chief extensors of vertebral column- maintains erect posture, lat flex head/vertebral column to same side
Semispinalis Thoracis
O: transverse processes T6-T10 *travels 4-6 vertebral segments I: spinous processes C6-T4 N: dorsal rami of most spinal nerves A: extends vertebral column and rotate to opposite side
Semispinalis Cervicis
O:transverse processe of T1-T5
I: spinous process C2-C5
N:dorsal rami of most spinal nerves
A: bi> extends cervical spine
un> rotate cervical spine to opposite side, lateral bend to same sideSemispinalis Capitis
O: transverse processes of C7 and T1-T6, articular processes C4-C6
I: occiput b/t superior and inferior nuchal lines
N: dorsal rami of mos spinal nerves
A: bi>extends the head
un> lateral bend to same side and rotate head to opposite side
Obliquus Capitis Superior
O: transverse process of C1
I: b/t superior and inferior nuchal lines
N: suboccipital nerve (C1)
A: postural, extension and lateral flexion to same side
Obliquus Capitis Inferior
O: spinous process of C2
I: transverse process of C1
N: suboccipital
A: rotation/flexion to same side
Rectus Capitis Posterior Major/ Minor
O: major: spinous process C2
minor: posterior tubercle on the posterior arch of C1
I: inferior to the inferior nuchal line
N: dorsal rami of C1 (suboccipital)
A: postural, rotation/flexion same side, extension
Levator Costarum
O: transverse process of C7-T11
I: inferior ribs, 1 or 2 levels below
N: dorsal rami of spinal nerves
A: elevate the ribs, lateral bending of spine
Interspinales
-unite spinous processes of consecutive vertebrae
N:dorsal rami of spinal nerves
A: extends vertebral column
Intertransversarii
-unites transverse processes of consecutive vertebrae
N:dorsal rami of most spinal nerves
A: un> lat flex superior vertebrae
bi> extends vertebral column
Multifidus
O: sacrum, aponeurosis of erector spinae, PSIS and iliac crest, post. sacroiliac ligament, mammilary process of L1-L5, trans process of T1-T12, articular processes of C4-C7
*spans 2-4 vertebrae
I: spinous process of vertebra above from L5-C2
N:dorsal rami of spinal nerves
A: un>lat flex trunk and rot to opp side
bi>extends trunk and stabilizes the vertebral column
Rotatores
O:transverse process (all)
I: spinous process of vertebrae 1 or 2 above
N: dorsal rami of spinal nerves
A: ext vertebral column (bi)
rotate superior vertebrae to opp side (uni)
*brevis(1)
longus (2)
