Back Muscles Flashcards
Main action of trapezius?
Elevation, retraction and rotation of scapula
What are the extrinsic muscles of the back?
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid minor
- Rhomboid major
Main action of latissimus dorsi?
Extends, abducts and medially rotates humerus
Main action of levator scapulae?
- Elevates scapula
- Tilts glenoid cavity by rotating scapula
Main action of the rhomboid minor?
- Retracts scapula
- Rotates scapula to depress glenoid cavity
- Fix scapula to thoracic wall
Main action of rhomboid major?
- Retracts scapula
- Rotates scapula to depress glenoid cavity
- Fix scapula to thoracic wall
Innervation of trapezius?
- Spinal root of accessory nerve (CN XI)
- C3 & C4 cervical nerves
Innervation of latissimus dorsi?
Thoracodorsal nerves (C6, C7, C8)
Innervation of levator scapulae?
- Dorsal scapular (C5)
- Cervical nerves (C3 & C4)
Innervation of rhomboid minor?
Dorsal scapular nerve (C4 & C5)
Innervation of rhomboid major?
Dorsal scapular nerve (C4 & C5)
Proximal attachment of trapezius?
“MENS”
- Medial 1/3 of sup. nuchal line
- Ext. occipital protuberance
- Nuchal ligament
- Spinous processes of C7-T12
Distal attachments of trapezius?
“LAS”
- Lateral 1/3 of clavicle
- Acromion
- Spine of scapula
Proximal attachment of latissimus dorsi?
“I SIT”
- Inf. 3/4 ribs
- Spinous processes of T6-T12
- Iliac crest
- Thoracolumbar fascia
Distal attachments of latissimus dorsi?
Floor of intertubercular groove of humerus
Proximal attachment of levator scapulae?
Post. tubercles of transverse processes of C1-C4
Distal attachments of levator scapula?
Sup. part of medial border of scapula
Proximal attachment of rhomboid minor?
- Nuchal ligament
- Spinous processes of C7 & T1
Distal attachments of rhomboid minor?
Medial border of scapula from level of spine to inf. angle
Proximal attachment of rhomboid major?
Spinous processes of T2-T5
Distal attachment of rhomboid major?
Medial border of scapula from level of spine to inf. angle
What are the intermediate muscles of the back?
- Serratus posterior sup.
- Serratus posterior inf.
What are the superficial intrinsic muscles of the back?
Splenius muscles:
- Splenius capitus
- Splenius cervicis
What are the intermediate intrinsic muscles of the back?
Erector spinae muscles (I Love Sex):
- Iliocostalis
- Longissimus
- Spinalis
What are the transversospinalis intrinsic muscles of the back?
- Semispinalis muscles: capitus, cervicis and thoracis
- Multifidus (deep to semispinalis)
- Rotatores (deep to multifidus)
What are the minor deep intrinsic muscles of the back?
- Interspinales
- Intertranversarii
- Levator costarum
Main action of the splenius muscles?
- Extension of head and neck
- Lateral rotation of head
Main action of erector spinae muscles?
- Extension of vertebral column & head
- Lateral bending of vertebral column
Main action of transversospinalis muscles?
- Extension of head
- Extension of thoracic and cervical vertebrae
- Contralateral rotation of vertebral column
- Stabilization of vertebral column during movement
Main action of minor deep muscle layer?
Aids in:
- extension, rotation and lateral bending of vertebral column
- elevates ribs for inspiration (levator costarum only)
Innervation of splenius muscles?
Dorsal rami of spinal nerves
Innervation of erector spinae muscles?
Dorsal rami of spinal nerves
Innervation of transversospinalis muscles?
Dorsal rami of spinal nerves
Innervation of minor deep muscles layers?
Dorsal and ventral rami of spinal nerves
Proximal attachment of splenius muscles?
- Nuchal ligament
- Spinous processes (C7-T3)
Distal attachment of splenius muscles?
- S. Capitus:
- mastoid process
- sup. nuchal line - S. Cervicis:
- post. tubercle of transverse processes of C1-C3
Proximal attachment of erector spinae muscles?
- Post. part of iliac crest
- Post. surface of sacrum
- Sacral & inf. lumbar spinous process
- Supraspinous ligament
Distal attachment of erector spinae muscles?
- Iliocostalis:
- angle of lower ribs
- cervical transverse processes - Longissimus
- ribs between tubercle and angles
- transverse processes of thoracic and cervical regions
- mastoid process of temporal bone - Spinalis
- Spinous processes in upper thoracic region
- skull
Proximal attachment of transversospinalis muscles?
- Transverse processes
- Sacrum and ilium (multifidus only)
Distal attachment of transversospinalis muscles?
- Semispinalis:
- occipital bone
- spinous processes in cervical and thoracic regions - Multifidus
- spinous processes of vertebrae above it - Rotatores:
- spinous processes of vertebrae above it
- skull
Proximal attachment of minor deep muscle layer?
- Interspinales: spinous processes
- Intertransversarii: transverse processes
- Levator costarum: tips of transverse processes
Distal attachment of minor deep muscle layers?
- Interspinales: sup. spinous processes
- Intertranversarii: adjacent transverse processes
- Levator costarum: rib (between tubercle and angle)
