Neck, Back, Abdominal Muscles

Action, Origin, Insertion, Nerve/Innervation

trapezius upper fibers

A: bilat extend head & neck; unilat ipsilat lat flex head & neck, contralat rotate head & neck, elevate & upwardly rotate scapula (S/T joint), elevate clavicle

O: extl occipital protuberance, med portion of sup nuchal ligament, spinous processes of C7-T12

I: lat 1/3 of clavicle, acromion, scapular spine

N: spinal accessory of CN XI, ventral rami of C2-C4

trapezius middle fibers

A: add/retract, stabilize scapula (S/T joint)

O: extl occipital protuberance, med portion of sup nuchal ligament, spinous processes of C7-T12

I: lat 1/3 of clavicle, acromion, scapular spine

N: spinal accessory of CN XI, ventral rami of C2-C4

trapezius lower fibers

A: depress, upwardly rotate scapula (S/T joint)

O: extl occipital protuberance, med portion of sup nuchal ligament, spinous processes of C7-T12

I: lat 1/3 of clavicle, acromion, scapular spine

N: spinal accessory of CN XI, ventral rami of C2-C4

muscles that upwardly rotate the scapula (SALUTE)

Serratus Anterior, Lower & Upper Trapezius, Elevate/upwardly rotate the scapula

latissimus dorsi

A: extend, add, med rotate shoulder (G/H joint)

O: inf angle of scapula, spinous processes of T7-T12, ribs 10-12, thoracolumbar fascia, post iliac crest

I: intertubercular groove of humerus

N: thoracodorsal C6-C8

rhomboid major

A: add, elevate, downwardly rotate scapula (S/T joint)

O: spinous processes of T2-T5

I: med border of scapula b/n the spine and the inf angle

N: dorsal scapular C4-C5

rhomboid minor

A: add, elevate, downwardly rotate scapula (S/T joint)

O: spinous processes of C7-T1

I: upper portion of med border of scapula

N: dorsal scapular C4-C5

levator scapula

A: bilat extend head & neck; unilat elevate & downwardly rotate scapula (S/T joint), lat flex head & neck, ipsilate rotate head & neck

O: transverse processes of C1-C4

I: med border of scapula b/n the sup angle & sup portion of spine

N: ventral rami C3-C4, dorsal scapular C4-C5

erector spinae group

iliocostalis, longissimus, spinalis

A: bilat extend vertebral column; unilat ipsilat flex vertebral column

O: common tendon (thoracolumbar fascia) attached to spinous processes of T11-L5, iliac crest, post surface of sacrum

I: post ribs, spinous & transverse processes of T & C vertebrae, mastoid process of temporal bone

N: dorsal rami

iliocostalis

A: bilat extend vertebral column; unilat ipsilat flex vertebral column

O: common tendon (lumborum), post surface of ribs 1-2 (thoracis & cervicis)

I: transverse processes of L1-L3 & post surfaces of ribs 6-12 (thoracis); transverse processes of lower cervicals (cervicis)

N: dorsal rami

longissimus

A: bilat extend vertebral column; unilat ipsilat flex vertebral column

O: common tendon (thoracis), transverse processes of T1-T5 (cervicis & capitis)

I: lower 9 ribs, transverse processes of thoracic (thoracis) & of cervical (cervicis), mastoid process of temporal bone (capitis)

N: dorsal rami

spinalis

A: bilat extend vertebral column; unilat ipsilat flex vertebral column

O: spinous processes of upper lumbar & lower thoracic vertebrae (thoracis)

I: spinous processes of upper thoracic (thoracis) & of C2-C7 (cervicis)

N: dorsal rami

serratus post sup & inf

A: elevate & depress ribs

O: nuchal ligament & spinous process of C7-T3 (sup); spinous process of T11-L2 (inf)

I: ribs 2-5 (sup); ribs 9-12 (inf)

N: intercostal nerves

splenius capitis

A: extend, ipsilat rotate, lat flex head & neck

O: lower hald of nuchal ligament, spinous proces of C7-T3

I: mastoid process, occipital bone

N: dorsal primary rami

splenius cervicis

A: extend, psilat rotate, lat flex head & neck

O: spinous process of T3-T6

I: transverse process of C1-C3

N: dorsal primary rami

suboccipital muscles

rector capitis minor & major; obliquus capitis sup & inf

A: cranial/occipital/capital extension, rotation

O: occiput

I: C1 & C2 (rectus capitis major, obliquus capitis inf), post tubercle of atlas (rectus capitis minor), transverse process of atlas (obliquus capitis sup, obliquus capitis inf)

cervical global/superficial stability muscles

SCM, scalenes, levator scapula, upper trapezius, erector spinae

lumbar global/superficial stability muscles

rectus abdomini, obliques, quadratus lumborum, erector spinae, iliopsoas

cervical deep segmental muscles

rectus capitis ant, rectus capitis lat, longus colli, longus capitis

lumbar deep segmental muscles

transversus, multifidi, deep quadratus lumborum, intersegmental rotators & transversari

sternocleidomastoid (SCM) & scalenes

A: bilat lower cervical flex; unilat. ipsilat flex, contralat rotation

longus colli muscles

rectus capitis ant & rectus capitus lateralis; craniocervical flexors important during retraction when SCM contracts → prevents hyperlordosis & segmental stability with trapezius

rectus abdominis

A: trunk flexion

extl obliques

A: bilat flex trunk; contralat rotation

intl obliques

A: bilat flex trunk; ipsilat flex & rotation

transverse abdominis

A: inr IAP; segmental stability; rotation

quadratus lumborum

A: ipsilat pelvic hiking, ipsilat flex trunk

multifidi

A: extend spine, contralat rotation