Back Muscles Flashcards
what is the origin of the latissimus dorsi?
-spinous processes T7-T12
-thoraco lumbar aponeurosis (attaches latissimus dorsi and some of the deeper spinal muscles
-dorsal face of sacrum
-dorsal 1/3 of the iliac crest
-10th -12th ribs
-inferior angle of the scapula
what is the insertion of the latissimus dorsi?
the humorous, floor of interburcular sulcus
what are the actions of the latissimus dorsi?
-adduction, rotation and extension of the arm
-elevation with arms fixed on a bar
-action on the shoulder girdle
what is the nerve supply of the latissimus dorsi?
thoraco dorsal nerve from the brachial plexus
what is the brachial plexus?
network of nerves in the shoulder that carries movement and sensory signals from the spinal chord to the arms and the hands
what are the attatchments of the trapezius?
-superior nuchal line
-nuchal ligament
-C7-T12
what are the insertions of the trapezius?
descending -lateral third of clavicle
horizontal - acromion of the scapula
ascending - spine of the scapula
what are the actions of the trapezius?
-keeps shoulder girdle up
tilts the scapula for arm elevation
-can depress and pull the scapula medially
-flattens the thoracic kyphosis
what is the nerve supply to the trapezius?
cranial nerve 11 accessory
what is the origin of the rhomboid?
major - spinous processes C6-C7
minor - spinous processs of T1-T4
what are the insertions of the rhomboid?
minor - root of scapular spine
major - below scapular spine
what is the nerve supply of the rhomboid?
dorsal scapular nerve from brachial plexus
what is the action of the rhomboid?
-retract scapula, rotate glenoid inferiorly
-fix scapula to trunk (together with serrates anterior. failure in this actin -> wing scapula)
what are the attachments of the levator scapulae?
vertebrae C1-C4
superior angle of the scapula
what is the action of the elevator scapulae?
elevates scapula and rotates glenoid inferiorly
with fixed shoulder girdle it extends the neck
