Superficial Back Muscles
Trapezius Insertion (3)
1. Lateral 1/3 clavicle 2. acromion 3. scapular spine
Latissimus dorsi Origin (3)
1. spinous processes of T7-L5 2. Sacrum connected by the thoracolumbar facia 3. iliac crest
Origin of Trapezius (4)
1. superior nuchal line (ridge found on posterior aspect of occipital bone) 2. external occipital protuberance (inion) 3. spinous processes C7-T12 4. ligamentum nuchea ( ligament that attaches trapezius to cervical region)
Trapezius Innervation
Cranial nerve XI (Spinal Accessory)
Latissimus dorsi action (3)
Extend, adduct and medially rotate humerus
Latissimus dorsi insertion
Intertubercular sulcus of humerus (on proximal anterior side of humerus)
Intermediate Back Muscle Action
Primarily proprioception (possibly respiratory function as well)
Rhomboid Major Origin
Spinous process T2-T5
Innervation of most deep back muscles
dorsal (posterior) rami of spinal nerves
Innervation of Rhomboids (major and minor) and levator scapulae
dorsal scapular nerve (levator scapulae also innervated with cervical nerves)
Levator scapulae action
elevates scapula
Actions of trapezius (4)
elevation, depression and rotation of scapula and scapular retraction
Deep Back Muscle Action
extend and rotate vertebral column, postural muscles
Rhomboid Minor Insertion
medial scapular border (at spine)
Rhomboid Major Insertion
medial scapular border (inferior to spine)
Levator scapulae insertion
medial scapular border (superior to the spine)
Superficial Back Muscle Action
move upper extremity (scapular and humeral attachments)
Rhomboid Major action
retracts/elevates scapula
Rhomboid minor action
retracts/elevates scapula
Rhomboid Minor Origin
spinous process C7-T1
What other muscle is also innervated with cranial nerve XI?
sternocleidomastoid
Latissimus dorsi innervation
thoracodorsal nerve
Levator scapulae origin
transverse processes C1-C4
Innervation of (most) superficial and intermediate back muscles
ventral (anterior) rami of spinal nerves
