Back Muscles Flashcards
Trapezius
O: external occipital protuberance, Superior nuchal line, nuchal ligament, and spinous processes of C7-T12
I: Lateral third of clavicle, acromion, and spine of scapula
N: Accessory nerve (cranial nerve XI)
B: transverse cervical artery, dorsal perforating branches of posterior intercostal arteries
A: Elevates, retracts, and rotates scapula; lower fibers depress scapula
Latissumus Dorsi
O: Spinous processes of T7-L5, sacrum, thoracolumbar fascia, iliac crest, and last three ribs
I: Humerus (intertubercular groove
N: Thoracodorsal nerve (C6-C8)
B: thoracodorsal artery, dorsal perforating branches of 9th/10th/11th posterior intercostal/subcostal, first 3 lumbar arteries
A: Extends, adducts, and medially rotates humerus
Rhomboid Minor
O: nuchal ligament and spinous processes of C7-T1
I: Medial border of scapula
N: Dorsal scapular nerve (C4-C5)
B: Dorsal scapular artery; deep branch of transverse cervical artery; dorsal perforating branches of the upper 5/6 posterior intercostal arteries
A: Retract scapula, rotate it to depress glenoid cavity, and fix scapula to thoracic wall
Rhomboid Major
O: Major: spinous processes of T2-T5
I: Medial border of scapula
N: Dorsal scapular nerve (C4-C5)
B: Dorsal scapular artery; deep branch of transverse cervical artery; dorsal perforating branches of the upper 5/6 posterior intercostal arteries
A: Retract scapula, rotate it to depress glenoid cavity, and fix scapula to thoracic wall
Serratus Posterior Superior
O: Ligamentum nuchae and spinous processes of C7-T3 I: Superior aspect of ribs 2-5
N: T1-T4 anterior rami
B: Posterior intercostal arteries
A: Elevates ribs
Serratus Posterior Inferior
O: Spinous processes of T11-L3 I: Inferior border of ribs 9-12 N: T9-T12 anterior rami B: Posterior intercostal arteries A: Depresses ribs
What muscles make up extrinsic back muscles?
- Trapezius
- Latissmus Dorsi
- Levator Scapulae
- Rhomboid minor/major
- Serratus Posterior Superior/Inferior
What muscles make up intermediate muscles of back?
Splenius Capitus and Cervicus
Splenius capitus
O: Nuchal ligament, spinous processes of C7-T4
I: Mastoid process of temporal bone and lateral third of superior nuchal line
N: Dorsal rami of middle cervical nerves
B: Descending branch of occipital artery, deep cervical artery
A: Bilaterally: extends head
Unilaterally: laterally bends (flexes) and rotates face to same side
Splenius Cervicus
O: Spinous processes of T3-T6
I:Transverse processes of C1-C3
N: Dorsal rami of middle cervical nerves
B: Descending branch of occipital artery, deep cervical artery
A: Bilaterally: extends neck
Unilaterally: laterally bends (flexes) and rotates neck toward same side
Muscles that make up Deep muscles of the back
Erector Spinae Group and Transversospinalis Group
Erector spinae group
Iliocostalis, Longissmus, Spinalis
Illiocostalis
O: Posterior sacrum, iliac crest, sacrospinous ligament, supraspinous ligament, and spinous processes of lower lumbar and sacral vertebrae
I:angles of lower ribs and cervical transverse processes
N: Dorsal rami of each region
B: c-occipital/deep cervical/vertebral arteries
t-dorsal branches of posterior intercostal/subcostal/and lumbar arteries
s-dorsal branches of lateral sacral arteries
A: Extends and laterally bends vertebral column and head
Longissimus
O: Posterior sacrum, iliac crest, sacrospinous ligament, supraspinous ligament, and spinous processes of lower lumbar and sacral vertebrae
I:between tubercles and angles of ribs, transverse processes of thoracic and cervical vertebrae, mastoid process
N: Dorsal rami of each region
B: c-occipital/deep cervical/vertebral arteries
t-dorsal branches of posterior intercostal/subcostal/and lumbar arteries
s-dorsal branches of lateral sacral arteries
A: Extends and laterally bends vertebral column and head
Spinalis
O: Posterior sacrum, iliac crest, sacrospinous ligament, supraspinous ligament, and spinous processes of lower lumbar and sacral vertebrae
I: Spinalis: spinous processes of upper thoracic and midcervical vertebrae
N: Dorsal rami of each region
B: c-occipital/deep cervical/vertebral arteries
t-dorsal branches of posterior intercostal/subcostal/and lumbar arteries
s-dorsal branches of lateral sacral arteries
A: Extends and laterally bends vertebral column and head
Thoracolumbar fascia
Connective tissue enclosing the erector spinae muscles
Transversopinalis group
Semi-spinalis, multifidus, and rotatores: Rotate and extend vertebral column
Semi-spinalis
O: Transverse processes of C4-T12
I: Spinous processes of cervical and thoracic regions
N: Dorsal rami of spinal nerves
B: c- occipital/deep cervical/vertebral arteries
t- dorsal branches of posterior intercostal arteries
A:Extends head, neck, and thorax and rotates them to opposite side
-Spans 4-6 muscles, and is located in vertebral regions of Capitus, Cervical, Thoracic
Mutifidus
O: Sacrum, ilium, and transverse processes of T1-T12 and articular processes of C4-C7
I: Spinous processes of vertebrae above, spanning two to four segments
N: Dorsal rami of each region
B: c- occipital, deep cervical, and vertebral arteries
t-branches of posterior intercostal/subcostal/and lumbar arteries
s- dorsel branches of lateral sacral arteries
A: Stabilizes spine during local movements
-Spans 2-4 vert
-Located in cervical, thoracic, lumbar (most prominent)
Rotatores
O: Transverse processes of cervical, thoracic, and lumbar regions
I: Lamina and transverse process or spine above, spanning one or two segments
N: Dorsal rami of spinal nerves
B: dorsal branches of segmental arteries
A: Stabilize, extend, and rotate spine
-Spans 1-2 vert
-Cervical, thoracic, lumbar; most prominent in thoracic
Levator scapulae
O: posterior tubercles of transverse processes of C1-C4
I: medial border of scapula from superior angle to spine
N: Ventral rami of C3-C4 and dorsal scapular nerve
B: dorsal scapular artery, transverse cervical artery, ascending cervical artery
A: Elevate scapula medially, inferiorly rotates glenoid cavity
