Anatomy back muscles

Trapezius origin

occipital protuberance, superior nuchal line, nuchal ligament, spinous process C7-T12

Trapezius insertion

Spine of scapula, acromion, clavicle

Trapezius action

Elevate, retract, and depress shoulder

Latissimus Dorsi origin

Thoracolumbar fascia, iliac crest, inferior 3-4 ribs, T7-T12 spinous process

Latissimus Dorsi insertion

floor of intertubercular groove of humerus

Latissimus Dorsi action

Adduct, extend, and medially rotate arm

Rhomboid Minor origin

nuchal ligament, C7-T1 spinous processes

Rhomboid Minor insertion

Superior medial border of scapula (at spine)

Rhomboid Major origin

T2-T5 spinous processes

Rhomboid Major insertion

Medial border of the scapula between the spine of the scapula and inferior angle

Rhomboids action

scapular retraction and elevation

Levator Scapulae origin

transverse processes of C1-C4

Levator Scapulae insertion

superior medial border of scapula

Levator Scapulae action

elevates shoulder

Serratus posterior superior origin

C6-T2

Serratus posterior superior insertion

2nd-5th ribs

Serratus posterior inferior origin

thoracolumbar fascia, upper lumbar vertebrae

Serratus posterior inferior insertion

9th-12th ribs

Serratus posterior action

accessory respiratory muscles

Multifidus mnemonic

Please Prepare All Students, My Teaching Assistants

multifidus pelvic and sacral origin (PPAS)

Posterior sacrum, PSIS of ilium, Aponeurosis of erector spinae, Sacroiliac ligaments

multifidus lumbar and thoracic origin (MY)

Mammillary processes of lumbar vertebrae, Transverse processes of Thoracic vertebrae

multifidus cervical origin

Articular processes of C4-C7

Multifidus insertion

spinous processes 2-4 segments superior to origin

Multifidus unilateral Action

Rotation to contralateral side

Multifidus bilateral Action

spinal extension

Rotatores origin

Transverse processes of vertebrae

Rotatores insertion

Spinous process of lamina/transverse process junction 1-2 segments superior to origin

Rotatores unilateral action

rotates vertebral column toward opposite side

Rotatores bilateral action

extend trunk

Erector spinae muscles

iliocostalis, longissimus, spinalis

iliocostalis origin

iliac crest, lumbar vertebrae, sacrum

iliocostalis insertion

Inferior angles of lower 6/7 ribs

Longissimus origin

lumbosacral aponeurosis, lumbar vertebrae

Longissimus insertion

lower 9-10 ribs, thoracic vertebrae

Spinalis origin

spinous process of upper lumbar and lower thoracic vertebrae

Spinalis insertion

spinous process of upper thoracic vertebrae

Erector spinae unilateral action

laterally flex vertebral column

Erector spinae bilateral action

extend vertebral column and head

Semispinalis muscles

capitis, cervicis, thoracis

Semispinalis origin

Transverse process of C4-T10 vertebrae

Semispinalis insertion

occipital bone, spinous processes of upper thoracic and cervical every 4-6

Suboccipital muscles

Rectus capitis posterior major and minor, Obliquus capitis inferior and superior

splenius origin

Nuchal ligament and spinous processes of C7-T6

Splenius capitis insertion

Mastoid process of temporal bone and lateral 1/3 of superior nuchal line

Splenius cervicis insertion

tubercles of transverse processes of C1-C3/C4

Splenius unilateral action

laterally flexes neck and rotates head to side of active muscles

Splenius bilateral action

Extend head and neck

BONUS: what are the borders of triangle of auscultation

medial border of scapula, lateral border of trapezius, superior border of latissimus dorsi

trapezius innervation

Spinal Accessory N (CN XI)

latissimus dorsi innervation

thoracodorsal nerve

Rhomboids innervation

Branches of brachial plexus

Levator scapulae innervation

Branches of brachial plexus

serratus posterior superior innervation

2nd-5th intercostal nerves

serratus posterior inferior innervation

9th-11th intercostal nerve

splenius capitis & splenius cervicis innervation

posterior rami of spinal nerves

erector spinae innervation

Posterior rami of spinal nerves

multifidus innervation

posterior rami of spinal nerves

rotatores innvervation

posterior rami of spinal nerves

semispinalis innervation

posterior rami of spinal nerves