Back Muscles

What are the superficial back muscles?

Traps;

Lev. Scap;

Rhomboid Min and Maj;

Lats

Trapezius

What muscle is this?

Trapezius proximal attachment

Superior nuchal line;

External occipital protuberance;

Nuchal ligament;

Spinous processes of C7-T12

Trapezius distal attachment

Lateral 1/3 of clavicle;

Acromion;

Spine of scapula

Trapezius action

Scapular:

Elevation, retraction, rotation, and depression

Levator Scapulae

What muscle is this?

Levator Scapulae proximal attachment

Posterior tubercles of transverse processes of C1-C4

Levator Scapulae distal attachment

Medial border of scapula superior to spine (superior angle)

Levator Scapulae action

Scapular elevation (medially) and inferior glenoid fossa rotation

Levator Scapulae innervation

Anterior rami of C3-4 and dorsal scapular nerve

Trapezius innervation

Accessory nerve (CN XI)

Rhomboid Minor

What muscle is this?

Rhomboid Minor proximal attachment

Nuchal ligament;

Spines of C7 and T1 vertebrae

Rhomboid Minor distal attachment

Medial border of scapula at spine of scapula

Rhomboid Minor action

Fixes scapula to thoracic wall;

Retracts and rotates it to depress glenoid cavity

Rhomboid Minor innervation

Dorsal scapular nerve

Rhomboid Major

What muscle is this?

Rhomboid Major proximal attachment

Spinous processes of T2-5 vertebrae

Rhomboid Major distal attachment

Medial border of scapula below base of spine of scapula

Rhomboid Major action

Fixes scapula to thoracic wall;

Retracts and rotates it to depress glenoid cavity

Rhomboid Major innervation

Dorsal scapular nerve

Latissimus Dorsi

What muscle is this?

Latissimus Dorsi proximal attachment

S processes of T7-L5;

Thoracolumbar fascia;

Iliac crest;

Ribs 9-12

Latissimus Dorsi distal attachment

Intertubercular groove of humerus

Latissimus Dorsi action

Extends, adducts, and internally rotates humerus

Latissimus Dorsi innervation

Thoracodorsal nerve

Semispinalis

what muscle is this?

Semispinalis proximal attachment

transverse processes of C4-T12

Semispinalis distal attachment

Spinous processes of 3-5 levels above in thoracic, cervical

Occipital bone

Semispinalis action

Extension of head and neck and vertebral column

Contralateral rotation (opposite)

Semispinalis innervation

posterior rami of spinal nerves

Multifidus

what muscle is this?

Multifidus proximal attachment

Posterior sacrum;

Posterior superior iliac spine;

Aponeurosis of erector spinae;

Sacro-iliac ligaments;

Mammillary processes of L vertebrae;

T processes of T1-3;

Articular processes of C4-7

Multifidus distal attachment

Spinous processes 2-4 segments above

where is multifidus the thickest?

lumbar region

Multifidus action

stabilization of vertebrae;

extension

Multifidus innervation

posterior rami of spinal nerves

Rotatores

what muscle is this?

Rotatores proximal attachment

transverse processes of vertebrae

where is Rotatores best developed?

thoracic region

Rotatores distal attachment

lamina and spinous processes of vertebra 1-2 levels above

Rotatores action

stabiliation;

extension;

proprioception

Rotatores innervation

posterior rami of spinal nerves

What is the innervation to rhomboid major, minor, and levator scapulae?

dorsal scapular nerve (ventral rami)

Splenius

what muscle is this?

Splenius proximal attachment

Nuchal ligament;

Spinous processes of C7-T6

Splenius capitis distal attachment

mastoid process and superior nuchal line

Splenius cervicis distal attchment

tubercles of transverse processes of C1-4

Splenius action

unilateral: ipsilateral rotation and side bending

bilateral: extension of head and neck

Splenius innervation

posterior rami of spinal nerves

what is the primary extensor of the head?

semispinalis capitis

Iliocostalis

what muscle is this?

Iliocostalis proximal attachment

broad tendon from posterior iliac crest, sacrum, and spinous processes of lumbar and sacrum

Iliocostalis distal attachment

lumborum, thoracis, cervicis;

Angles of lower ribs and cervical transverse processes

Iliocostalis action

bilateral: extend vertebral column and head

unilateral: lateral flexion

Longissimus

what muscle is this?

Longissimus proximal attachment

broad tendon from posterior iliac crest, sacrum, and spinous processes of lumbar and sacrum

Longissimus distal attachment

thoracis, cervicis, capitis;

ribs and transverse processes of thoracic and cervical spine

mastoid of temporal bone

Longissimus action

bilateral extension;

unilateral lateral flexion

Longissimus innervation

posterior rami of spinal nerves

Spinalis

what muscle is this?

Spinalis proximal attachment

broad tendon from iliac crest, sacrum, and spinous processes of lumbar and sacrum

Spinalis distal attachment

spinouss processes of thoracic, cervical;

Nuchal line of occipital bone

where is multifidius the thinnest?

thoracic

layers of multifidus

superficial (3-5 layers)

deep (1 layer)

what do multifidus, rotatores, abnd sub-occipital triangle muscles all have that helps give feedback on their positition in space?

proprioceptors

what are the muscles in the sub-occipital triangle?

obliquus capitis superior, obliquus capitis inferior, rectus capitis posterior major

what structure is the "floor" of the triangle?

transverse process of C1

what structures run through the sub-occipital triangle?

vertebral artery;

suboccipital nerve

obliquus capitis superior attachments

transverse process of C1 to occipital bone

obliquus capitis inferior attachments

posterior tubercle of posterior arch of C2 to transverse process of C1

rectus capitis posterior major attachments

spinous process of C2 to occipital bone

rectus capitis posterior minor attachments

posterior tubercle of posterior arch of C1 to medial inferior nuchal line of occipital bone

innervation of sub-occipital muscles

suboccipital nerve (dorsal ramus C1)

what does the greater occipital nerve do?

provides sensory only to the back of neck and head

serratus posterior superior proximal attachment

nuchal ligament; spinous C7-T3

serratus posterior superior distal attachment

ribs 2-4

serratus posterior superior action

elevates ribs

serratus posterior superior innervation

intercostal nerves

serratus posterior inferior proximal attachment

Spinous processes of T11-L2

serratus posterior inferior distal attachment

Ribs 8-12

serratus posterior inferior action

depresses ribs

serratus posterior inferior innervation

intercostal nerves