Back Myology Flashcards
extrinsic (superficial) layers
innervated by a branch of an anterior ramus or cranial nerve
intrinsic (deep) layers
innervated by posterior rami
layer 1 Ms.
(extrinsic)
trapezius M.
latissimus dorsi M.
layer 2 Ms.
(extrinsic)
rhomboid major M.
rhomboid minor M.
levator scapulae M.
layer 3 Ms.
(extrinsic)
serratus posterior superior M.
serratus posterior inferior M.
layer 4 Ms.
(intrinsic)
splenius capitis M.
splenius cervicis M.
layer 5 Ms.
(intrinsic, largest layer, erector spinae group)
iliocostalis Ms. (lateral group)
longissimus Ms. (intermediate group)
spinalis Ms. (medial group)
iliocostalis (lateral group) Ms.
iliocostalis lumborum M.
iliocostalis thoracis M.
iliocostalis cervicis M.
longissimus (intermediate group) Ms.
longissimus thoracis M.
longissimus cervicis M.
longissimus capitis M.
spinalis (medial group) Ms.
spinalis thoracis M.
spinalis cervicis M. (usually absent)
spinalis capitis M. (usually absent)
layer 6 Ms.
(intrinsic, transversospinalis group) semispinalis Ms. multifidus M. rotatores lonus M. rotatores brevis M.
semispinalis Ms.
semispinalis thoracis M.
semispinalis cervicis M.
semispinalis capitis M.
other deep back Ms.
interspinalis M.
intertransversarii M.
levator costarum longus M.
levator costarum brevis M.
suboccipital region Ms.
rectus capitis posterior major M.
rectus capitis posterior minor M.
obliquus capitis inferior M.
obliquus capitis superior M.
back sprain
injury to ligamentous attachments between bone, usually the result of inadequate stretching
back strain
excessive stretching and sometimes tearing of muscle fibers produced by overly strong muscular contraction
muscle tissue will spasm in response to injury and inflammation as a protective measure
muscle spasm
involuntary contraction
trapezius M.
O: spinous processes of C7-T12, ligamentum nuchae, external occipital protuberance, medial 1/3 of superior nuchal line of occipital B.
I: lateral 1/3 of clavicle, acromion, and scapular spine
A: whole muscle (rotate point of glenoid cavity superiorly, retract the scapula), upper fibers (elevate scapula), lower fibers (depress scapula), with scapula fixed the upper fibers will extend the neck working bilaterally, laterally flex the neck and rotate the face AWAY when working unilaterally
iN: motor - spinal accessory N. (CN XI), sensory - C3,4
latissimus dorsi M.
O: spinous process of T6-T12, ribs 9-12, iliac crest and spinous processes of L1-L5 and median sacral crest via thoracolumbar fascia
I: floor of the humeral intertubercular groove
A. extend, adduct and medially rotate the humerus, rotate the glenoid cavity inferiorly
iN: thoracodorsal N. (C6-8)
rhomboid major M.
O: spinois processes of T2-T5
I: medial border of scapula (inferior to scapular spine)
A: retract and elevate scapula, rotate the glenoid cavity inferiorly
iN: dorsal scapular N. (C4,5)
rhomboid minor M.
O: spinous processes of C7-T1
I: medial border of scapula (at scapular spine)
A: retract and elevate scapula, rotate the glenoid cavity inferiorly
iN: dorsal scapular N. (C4,5)