Extrinsic Back Muscles Flashcards
what are the deep posterior thoracoappendicuar (extrinsic shoulder) muscles?
levator scapulae
rhomboid major
rhomboid minor
what are the superficial posterior thoracoapprendicular (extrinsic shoulder) muscles?
trapezius
latissimus dorsi
Trapezius
Origin
Insert
Originates: medial third of superior nuchal line, EOP, nuchal ligament, spinous processes C7-T12
Inserts: lateral third of clavicle; acromion and spine of scapula
(shoulder pads)
Trapezius
Nerve
Action
Innervation: Motor: spinal accessory nerve (CXI)
Sensory: C3, C4
Actions: elevation, depression, retraction rotation of glenoid cavity
Latissimus Dorsi
Origin
Insert
Originates: spinous process of inferior 6 thoracic vertebrae; thoracolumbar fascia, illiac crest and inferior 3 or 4 ribs
Insertion: floor of intertubercular sulcus of humerus
Latimissus Dorsi
Nerve
Action
Innervation: Thoracodorsal Nerve (C6, C7, C8: keep the lats great)
Action: extends, adducts, medial rotation of humerus
Levator Scapulae
Origin
Insert
Originates: posterior tubercles of transverse processes of C1-C4
Insertion: medial border of scapula superior to the root of the spine
Levator Scapulae
Nerve
Action
Innervation: Dorsal Scapular (C5), cervical nerves (C3, C4)
Action: elevates scapula and tilts glenoid cavity inferiorly
Rhomboid Minor
Origin
Insert
Originates: nuchal ligament, spinous process of C7 and T1
Insertion: root of the scapular spine
Rhomboid Minor
Nerve
Action
Innervation: Dorsal Scapular nerve (C4, C5)
Action: retraction of scapula and rotate it to depress glenoid cavity
Rhomboid Major
Origin
Insert
Originates: spinous process of T2-T5
Insertion: inferior to the root of the scapular spine (under the rhomboid minor- its just bigger)
Rhomboid Major
Nerve
Action
Innervation: Dorsal Scapular nerve (C4, C5)
Action: retract scapula and rotate it to depress the glenoid cavity
