Spinal Musculature Flashcards
What are the layers of the back muscles?
Extrinsic superficial (1st) Trapezius and Latissimus DorsiExtrinsic intermediate (2nd) Levator Scapulae, RhomboidsSuperficial Intrinsic (3rd) Splenius capitis, Splenius cervicisIntermediate Intrinsic (4th) Erector spinaeDeep intrinsic (5th) Semispinalis capitis and cervicis, Rotatores costarum, Interspinales, Intertransversales, Multifidus
What are the erector spinae muscles from lateral to medial?
Iliocostalis, longissimuis, spinalis
What muscles is iliocostalis divided into?
Iliocostalis lumborum, thoracis, and cervicis
What muscles is longissimus and spinalis divided into?
Longissimus/Spinalis thoracis, cervicis, and capitis
Bogduk suggest categorizing lumbar and thoracic portion of iliocostalis and longissimus into?
longissimus thoracis pars lumborum and thoracisIlliocostalis lumborum pars lumborum and thoracis
In Bogduk’s classification how do the muscles function differently in the lumbar region?
The line of action is on an oblique axis causing a shearing force in combination with an extensor movement of the superior vertebrae
In Bogduk’s classification the thoracic portion of the muscles are unique how?
They are parallel to the axis of compression to allow for greater extension
How are the erector spinae muscles innervated?
By dorsal rami of segmental spinal nerves
What back muscles are most medial of the lumbar back muscles?
Multifidus
How do the multifidus originate and insert?
Laminae or mammillary processes to the spinous of vertebrae 2 or 3 levels over their origin
What range do the multifidus cover?
Sacrum-C2
What motions activate multifidus?
Extension, lateral bend, and contralateral rotation
What is significant about the innervation of multifidus?
Many mechanoreceptors for initiating and correcting motion
What are intertransversarii muscles divided into?
Medial and lateral components
Which group of intertransversarii are considered part of the “true back”?
Medial component (innervated by dorsal rami as opposed to lateral portion)
