Muscles of Upper Limb that are dissected in Back Region Muscle Origin Insertion Action Innervation Artery Notes floor of thoraco thoraco inserting spines from intertubercular arm nerve (C7,8) a. tendon twists T7 to groove from so that fibers arm cord originating third medially of brachial highest insert of iliac plexus lowest crest, lower 3 or 4 ribs, sometimes from angle of latissimus dorsi levator e rhomboideus major rhomboideus minor anterior trapezius of C1-C4 spines of T2- T5 end of nuchae, spines of C7 T1 ribs 1-8 or 9 medial third of, external occipital of from angle to spine of to spine of of at root of spine of of on its costal (deep) surface lateral third of clavicle, medial of acromion upper elevates retracts, elevates ly retracts, elevates ly it draws forward; fibers rotate ly elevates depresses (depending on which r nerve (C5); upper part of receives branches of C3 & C4 r nerve (C5) r nerve (C5) long thoracic nerve (from ventral rami C5- C7) motor: spinal accessory (XI), proprioception: C3-C4 r a. r a. r a lateral thoracic a. cervical a. levator e is action shape shape a lesion of long thoracic nerve will cause winging of (i.e., medial border of falls away from chest wall looks like an angel's wing) shape; trapezius is an example of a that 1
protuberance, nuchae, of C7- T12 crest of r spine, tubercle of r spine part of contracts); ly; retracts migrates during development from its level of origin (cervical) to its final position, pulling its nerve artery along behind Muscles of Back Region Muscle Origin Insertion Action Innervation Artery Notes erector spinae iliac crest, of supraspinal ligament angles of ribs, of, aspect of skull head innervated by C1-S5,, lumbar erector spinae m. is separated into 3 columns of : iliocostalis, longissimus in an intermediate position spinalis medially; each of se columns has multiple named iliocostalis interspinales iliac crest sacrum upper border of intertransversarii upper border of angles of ribs lower border of lower border of trunk extend trunk bend trunk C4-S5,, lumbar,, lumbar parts most lateral part of erector spinae; it may be lumborum, thoracis cervicis portions se are small fairly insignificant s se are small fairly insignificant s 2
longissimus multifidus obliquus capitis obliquus capitis major minor at levels of C3-L5 of axis of atlas of axis tubercle of atlas at levels 2-4 levels to ir origin of atlas occipital bone medially head extend bend trunk, rotate to head to same head, head to same head, rotate to same head C1-S1,, lumbar,, lumbar,, lumbar intermediate part of erector spinae;it may be thoracis, cervicis capitis portions semispinalis, multifidus group greater occipital of C2) passes ly around margin of oblique triangle is formed by obliquus capitis rectus capitis major none minor is deeper inserts more medial than major rotatores long semispinalis, 3
semispinalis spinalis of C7-T12 thoracolumbar fascia, spines of T11- T12 L1-L2 nuchae, spines of C7 T1-T3 at levels rotatores: spines 2 origin; short rotatores: spines 1 origin capitis: back of skull between nuchal lines; cervicis & thoracis: spines 4-6 origin ribs 9-12, lateral to angles ribs 1-4, lateral to angles at levels base of skull column to trunk trunk to pulls down lower ribs elevates upper ribs trunk C1-T12 branches of ventral T9-T12 branches of ventral T1-T4 C2-L3,, lumbar,, lumbar lowest a., a., first two lumbar 1-4,, lumbar multifidus group three parts are named based on ir insertions: capitis, cervicis thoracis; semispinalis, multifidus group a respiratory, it receives ventral ramus innervation; embryonically related to s, not deep back mm. a respiratory, it receives ventral ramus innervation; embryonically related to s, not deep back mm. most medial part of erector spinae; may be thoracis, cervicis capitis portions 4
splenius splenius capitis splenius cervicis nuchae spines C7-T6 nuchae spines of C7-T6 nuchae spines of C7-T6 capitis: & ; cervicis: tubercles of C1-C3 lateral end of tubercles of of C1-C3 head; same head, same head, same splenius means bage; it gets its name from its broad, flat shape shape: splenius means bage capitis refers to insertion of this portion of shape: splenius means bage cervicis refers to insertion of this portion of 5