Back Muscles

Question 1

Trapezius

Answer 1

Prox: external occipital protuberance, ligament nuchae, spinous process c7~t12
Dist: scapular spine, acromial process, lat/dist 1/3 clavicle
Function: elevation, upward rotation and aDd or scap

Question 2

Latissimus Dorsi

Answer 2

“Swimmers muscle”
Prox: thoracolumbar fascia, iliac crest, spin process t6-t12, ribs, inf angle of scapula
Dist: medial hip or intertubercular sulcus (or humerus)
Fx: ir/ext/add of GH joint; accessory muscle for expiration

Question 3

Rhomboid minor

Answer 3

Prox: spin process of c7-t1
Dist: medial border or scap btw sup angle and root of scap spine
Fx: elevation, downward rotation & retraction/add or scap

Question 4

Rhomboid major

Answer 4

Prox: spin process of t2-t5
Dist: med border of scap inf to the scapular spine
Fx: elevation, downward rotation and retraction/add of scap

Question 5

Superior serrated posterior

Answer 5

Prox: supraspinous lig/log nuchae/spinous process c7-t3
Dist: superior border of ribs 2-5
Innervated by: intercostal nerve ventral rami
Fx: RESPIRATION: elevation upper ribs: inspiration

Question 6

Inferior Serratus Posterior

Answer 6

Prox: supraspinous lig/spinous process t11-l2
Dist: inferior border of ribs 9-12
Innervated by: intercostal nerve ventral rami
Fx: RESPIRATION: depress lower ribs: expiration

Question 7

Splenius Capitis

Answer 7

Prox: lig nuchae & spin process c7-t3
Dist: lat sup nuchal line & mastoid process
Fx: neck/head ext (B), ipsilateral SB/RT of head

Question 8

Splenius Cervicis

Answer 8

Prox: spin process t3-t6
Dist: transverse process c3-c6
Fx: neck ext (B), ipsilateral SB/RT of neck

Question 9

Iliocostalis Lumborum

Answer 9

Superficial intrinsic back muscle- erector spinae
Prox: lat erector spinae common tendon and iliac crest
Dist: inf border or angle of rob 6-7
Innervated by: dorsal rami of spinal nerve
Fx: bilateral: back ext (B)
Unilateral: ipsilateral back SB/RT (L/R)
*Lumborum and thoracic: depression of rib cage, expiration

Question 10

Iliocostalis Thoracis

Answer 10

Superficial intrinsic back muscle- erector spinae
Prox: sup angle of ribs 7-12 & medial tendon of Lumborum
Dist: super angle of ribs 1-6 and c7 transverse process
Innervated by: dorsal rami of spinal nerve
Fx: bilateral: back ext (B)
Unilateral: ipsilateral back SB/RT (L/R)
*Lumborum and thoracic: depression of rib cage, expiration

Question 11

Iliocostalis Cervicis

Answer 11

Superficial intrinsic back muscle- erector spinae
Prox: sup angle of ribs 3-6
Dist: posterior tubercle of transverse processes of c4-c6
Innervated by: dorsal rami of spinal nerve
Fx: bilateral: back ext (B)
Unilateral: ipsilateral back SB/RT (L/R)
Lumborum and thoracic: depression of rib cage, expiration

Question 12

Longissimus thoracis

Answer 12

Sup intrinsic back muscles- erector spinae
Prox: erect spinae common tendon, thoraculumbar fascia, transverse and maxillary process of lumbar vert
Dist: trans process of all thoracic vert and the lower 9-10 ribs btw the tubercles and angles
Innervated by: dorsal rami of spinal nerves
Fx: bilateral: back ext; cervicis/capitis: neck /head ext
Unilateral: ipsilateral back SB/RT; cervicis/capitis: ipsilateral RT of neck/head
Thoracis: depression of rib cage, expiration

Question 13

Longissimus cervicis

Answer 13

Sup intrinsic back muscles- erector spinae
Prox: transverse process or t1-t5
Dist: post tubercle or transverse processes of c2-c6

Innervated by: dorsal rami of spinal nerves
Fx: bilateral: back ext; cervicis/capitis: neck /head ext
Unilateral: ipsilateral back SB/RT; cervicis/capitis: ipsilateral RT of neck/head

Question 14

Longissimis Capitis

Answer 14

Sup intrinsic back muscles- erector spinae
Prox: trans processes of c4-t5
Dist: mastoid process ONLY ILS THAT HAS DISTAL ATTACHMENT TO THE CRANIUM
Innervated by: dorsal rami of spinal nerves
Fx: bilateral: back ext; cervicis/capitis: neck /head ext
Unilateral: ipsilateral back SB/RT; cervicis/capitis: ipsilateral RT of neck/head

Question 15

Spinalis Thoracis

Answer 15

Sup intrinsic back muscles - erector spinae
Prox: most proximally: L2 spinous process; clinically very important
Dist: spin process or thoracic vert, 4-8 higher levels
Innervated by: dorsal rami of spinal nerves
Fx: bilateral contraction: back ext
Unilateral contraction: ipsilateral back SB and RT (little movement produced by this muscle)

Question 16

Spinalis Cervicis

Answer 16

Sup intrinsic back muscles - erector spinae
Prox: spin process from t1-t2 and lig nuchae
Dist: spinous process c4-c1
Innervated by: dorsal rami of spinal nerves
Fx: bilateral contraction: back ext
Unilateral contraction: ipsilateral back SB and RT (little movement produced by this muscle)

Question 17

Spinalis Capitis

Answer 17

Sup intrinsic back muscles - erector spinae
Prox: spinous process t1/c7
Dist: superior nuchal line with semispinalis
Innervated by: dorsal rami of spinal nerves
Fx: bilateral contraction: back ext
Unilateral contraction: ipsilateral back SB and RT (little movement produced by this muscle)

Question 18

Multifidi

Answer 18

Deep intrinsic back muscles: transversospinalis
Core of back
Prox: sacrum, PSIS, IS lig, lumbar mammillary processes, transverse processes of t12-c4
Dist: lay aspect and tips of spinous processes of vert 2-5 levels above until c2
Fx: back ext (B); ipsilateral back SB and contra lateral RT (unilateral contraction)

Only muscle with attachment on the posterior surface of sacrum
Only muscle in the laminar groove below l2

Question 19

Senisplinalis Thoracis

Answer 19

Deep intrinsic back muscles
Covers multifidi partially, starts at T region
Prox: trans process of t10-t6
Dist: spin process of t6-t4
Fx: back ext (B), ipsilateral back SB (L/R) and contra lateral RT (L/R)

Question 20

Semispinalis Cervicis

Answer 20

Deep intrinsic back muscles
Covers multifidi partially, starts at T region
Prox: trans process of t6-t1
Dist: spin process of c5-c2
Fx: back ext (B), ipsilateral back SB (L/R) and contra lateral RT (L/R)
Cervicis/Capitis: head ext (B), ipsilateral head SB(L/R), contra lateral head RT (L/R)

Question 21

Semispinalis Capitis

Answer 21

Deep intrinsic back muscles
Covers multifidi partially, starts at T region
Prox: trans process of t7-c7, articulate processes of the c4-c6
Dist: btw sup/inf nuchal line, deep to trapezius attachment
C2 Pierce capitis for dernatome: greater occipital nerve
Fx: back ext (B), ipsilateral back SB (L/R) and contra lateral RT (L/R)
Cervicis/Capitis: head ext (B), ipsilateral head SB(L/R), contra lateral head RT (L/R)

Question 22

Rotator Longus and Brevis

Answer 22

Deep intrinsic muscle
Prox: trans process from t12-t2
Dist: spinous process: 1 level up (brevis), 2 levels up (longus)
Fx: back ext (B), ipsilateral SB and contra lateral RT

Question 23

Intertransversarii

Answer 23

Prox: transverse process of inf vert
Dist: trans process of sup vert
Fx: back ext (B), SB to ipsilateral

Question 24

Rectus Capitis posterior minor

Answer 24

Deep Neck Muscle
Prox: posterior tubercle of atlas
Dist: medial inf nuchal line
Fx: head ext

Question 25

Rectus capitis posterior major

Answer 25

Deep Neck Muscle
Prox: spinous process of axis
Dist: lateral inf nuchal line
Fx: head ext (B), ipsilateral RT (L/R)

Question 26

Obliques capitis inferior

Answer 26

Deep neck muscle
Prox: apex of axis spin process
Dist: transverse process of atlas
Fx: neck ext (B), ipsilateral SB/RT (L/R)

Question 27

Obliquus Capitis Superior

Answer 27

Deep neck muscle
Prox: trans process of atlas
Dist: btw sup and inf nuchal line
Fx: neck ext (b), ipsilateral SB (L/R), contra lateral RT (L/R)

Question 28

Suboccipital Triangle

Answer 28

Boundary:
Med: recurs capitis post major
Lat : obliquus capitis sup
Inf: obliquus capitis inf
Floor: vert artery
Roof: greater occipital nerve (c2 sensory only)/semispinalis capitis

Contents:
Suboccipital nerve: dorsal rami of c1

Important pathologies:
Headache: greater occipital neuralgia/ cervicogenic headache