back + cervical triangle OIIA

Trapezius

origin: medial third of superior nuchal line, external occipital protuberance, nuchal ligament, spinous process of c7-t12 vertebrae (medial)

insertion: lateral third of clavicle, acromion and spine of scapula (lateral)

innvervation: spinal accssory nerve c3, c4 spinal nerves

action: elevates, rotate glenoid cavity superiorly, extend neck, retract and depress scapula

rhomboid minor

origin: nuchal ligament; spinous process c7 and t1 vertebrae (medial)

insertion: triangular area at medial end of the scapular spine (lateral)

innvervation: dorsal sacpular nerve c4,c5

action: retract scapula and rotate glenoid cavity inferioly; fix scapula to thoracic wall

latissimus dorsi

origin: spinous process of t7-t12, thorocolumbar fasica, iliac crest, and inferior 3 or 4 ribs (medial)

insertion: floor of intertubecular sulcus (groove) of humerous

innervation: thoracodorsal scapular nerve c6,c7,c8

action: extends, adducts, and medially rotates shoulder joint, raises body towards arms during climbing

rhomboid major

origin: spinous process of t2-t5 (medial)

insertion: medial border of scapula from level of spine to inferior angle (lateral)

innvervation: dorsal scapular nerve c4, c5

action: retracts scapula and rotates glenoid cavity inferiorly; fix scapula to thoracic wall

levator scapulae

origin: posterior tubercles of transverse processes of c1-c4 vertebrae

insertion medial border of scapula superior to root of spine

innvervation: dorsal scapular c5, and cervical c3,c4 spinal nerves

action: elevates scapula, rotate the glenoidhumeral cavity inferiorly

thoracolumbar fascia

origin: aponeurosis tendon, superficial layer attaches to superficial muscles and deep layer surrounds deep muscles

splenius capitus (spinotransversalis)

origin: nuchal ligament and spinous process of c7-t6 vertebrae

insertion: mastoid process and superior nuchal line (occipital bone)

innvervation: posterior rami of spinal nerves

action: alone: laterally flex neck and rotate head to side of active muscles, together: extend head and neck

splenius cervicis (spinotransversalis)

origin: nuchal ligament and spinous process of c7-t6 vertebrae

insertion: tubercles of transverse process of c1-c3 or c4

innvervation: posterior rami of spinal nerves

action: alone: laterally flex neck and rotate head to side of active muscles, together: extend head and neck

iliocostalis (sarcospinalis/erector spinae)

origin: posterior iliac crest, posterior sacrum, sacro-iliac ligament, sacral and inferior lumbar spinous processes, supraspinatus ligament

insertion: angles of lower ribs, cervical transverse process

innervation: posterior rami of spinal nerves

action: acting bilaterally: extend vetebral column and head; as back is flexed control movemnt by gradually lengthening their fibers Acting Unilaterlly: laterally flex vetebral column

longtissmus (sarcospinalis/erector spinae)

origin: posterior iliac crest, posterior sacrum, sacro-iliac ligament, sacral and inferior lumbar spinous processes, supraspinous ligament

insertion:: ribs b/w tubercles and angles to transverse processes in thoracic and cervical region to mastoid proces

innervation: posterior rami of spinal nerves

action: acting bilaterally: extend vetebral column and head; as back is flexed control movemnt by gradually lengthening their fibers Acting Unilaterlly: laterally flex vetebral column

spinalis (sarcospinalis/erector spinae)

origin: posterior iliac crest, posterior sacrum, sacro-iliac ligament, sacral and inferior lumbar spinous processes, supraspinous ligament

insertion: spinous process in upper thoracic region to cranium

innervation: posterior rami of spinal nerves

action: acting bilaterally: extend vetebral column and head; as back is flexed control movemnt by gradually lengthening their fibers Acting Unilaterlly: laterally flex vetebral column

semispinalis (transversospinalis)

origin: transverse process of c4-t10

insertion: fibers run superomedially to occipital bone and spinous processes in upper thoracic and cervical regions, spanning four to six segments

innervation: posterior rami of spinal nerves

action: acting bilaterally: extend vetebral column and head; as back is flexed control movemnt by gradually lengthening their fibers Acting Unilaterlly: laterally flex vetebral column

multifidus (transversospinalis)

origin: posterior sacrum, posterior iliac spine of ilium, aponeruosis of erector spinae, sacro-iliac ligaments, mamilary processes of lumbar vertebrae, transverse processes of thoracic vertebrae, and articular processes of c4-c7

insertion: thickest in lumbar region, superomedially to entire length of spinous processes of vertebrae located 2-4 segments superior to origin

innervation: posterior rami of spinal nerves

action: acting bilaterally: extend vetebral column and head; as back is flexed control movemnt by gradually lengthening their fibers Acting Unilaterlly: laterally flex vetebral column

rotatores (transversospinalis)

origin: transverse process of vertebrae (best developed in thoracic region)

insertion: superomedially attach to junction of lamina and transverse process or spinous process immediately superior to vertebrae of origin

innervation: posterior rami of spinal nerves

action: acting bilaterally: extend vetebral column and head; as back is flexed control movemnt by gradually lengthening their fibers Acting Unilaterlly: laterally flex vetebral column

interspinalis (segmental)

origin: superior surface of spinous process of cervical and lumbar vertebrae

insertion: inferior surfaces of spinous process of vertebrae superior to vertebrae origin

innervation: posterior rami of spinal nerves

action: extension and rotation of vertebral column

intertransversi (segmental)

origin: transverse process of cervical and lumbar vertebrae

insertion: transverse process of adjacent vertebrae

innervation: posterior and anterior rami of spinal nerves

action: lateral flexion of vertebral column/bilaterally stabilizes vertebral column

obliquus capitis superior (suboccipital)

origin: transverse process of c1

insertion: occipital bone between the superior and inferior nuchal lines

innervation: posterior ramus of c1: suboccipital nerve

action: extend the head on c1, rotate head and c1 on c2 vertebrae

obliquus capitis inferior (suboccipital)

origin: spinous process of c2

insertion: transverse process of c1

innervation: posterior ramus of c1: suboccipital nerve

action: extend the head on c1, rotate head and c1 on c2 vertebrae

rectus capitis posterior major (suboccipital)

origin: spinous process of c2

insertion:lateral part of the inferior nuchal line and the occipital bone

innervation: posterior ramus of c1: suboccipital nerve

action: extend the head on c1, rotate head and c1 on c2 vertebrae

rectus capitus posterior minor (suboccipital)

origin: posterior tubercle of the arch of posterior arch of c1

insertion: medial third of the inferior nuchal line

innervation: posterior ramus of c1: suboccipital nerve

action: extend the head on c1, rotate head and c1 on c2 vertebrae

sternocleidomastoid

origin: lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line

insertion: sternal head: surface of manubrium of sternum; clavicular head: superior surface of medial third of clavicle

innervation: spinal accessory nerve, c2-c3

action: laterally flex ipsilaterally; contralaterally rotates; bilaterally: extends neck at atlanto occipital joint, flexes cervical vertebrae so chin approaches manubrium, chin thrust while head is kept level by extending superior cervical vertebrae while flexing inferior vertebrae (head protraction); when cervical vertebrae fixed, may elevate manubrium and medial end of clavicles to assist deep respiration (pump handle)

anterior scalene

origin: anterior tubercles of transverse process of c3-c6 vertebrae

insertion: 1st rib

innervation: cervical spinal nerves c4-c6

action: flexes neck laterally: elevates 1st rib during forced inspiration

middle scalene

origin: posterior tubercles of transverse process of c4-c7 vertebrae

insertion: superior surface of 1st rib: posterior to groove for subclavian artery

innervation: anterior rami of cervical spinal nerves

action: flexes neck laterally: elevates 1st rib during forced inspiraiton

posterior scalene

origin: posterior tubercles of transverse processes of c4-c6 vertebrae

insertion: external border of 2nd rib

innervation: anterior rami of cervical spinal nerves c7 and c8

action: flexes neck laterally, elevates 2nd rib during forced inspiration