3 main groups of back muscles

Origin for upper trapezius

superior nuchal line and external occipital protuberance of the skull

Origin of middle trapezius

ligamentum nuchae and spinous processes from C7 to T3 or T4

Origin of lower trapezius

spinous processes from T4 (or T5) through T12

Insertion of upper trapezius

lateral third of clavicle

Insertion of middle trapezius

acromion process and spine of scapula

Insertion of lower trapezius

medial part of scapular spine

Action for upper trapezius

elevates scapula and extends head and neck

Action for middle trapezius

retracts scapula

Action for lower trapezius

depresses scapula

Innervation for trapezius

cranial nerve 11 (XI) or spinal accessory nerve

Proprioception of trapezius

anterior rami of C3 and C4

Blood supply of trapezius

transverse cervical, suprascapular, and posterior intercostal arteries

Origin of latissimus dorsi

spinous processes of vertebrae T7 to L5, sacrum, iliac crest, and ribs 10-12

Insertion of latissimus dorsi

floor of intertubercular sulcus of humerus

Innervation of latissimus dorsi

thoracodorsal nerve

Action of latissimus dorsi

extend, adduct, and medially rotate humerus

Blood supply of latissimus dorsi

thoracodorsal artery

Origin of levator scapulae

transverse processes of C1 to C4

Insertion of levator scapulae

superior scapular angle

Innervation of levator scapulae

dorsal scapular nerve + C3-C4

Action of latissimus dorsi

elevates scapula

Blood supply of latissimus dorsi

dorsal scapular artery

Origin of rhomboid minor

ligamentum nuchae and spinous processes of C7 and T1

Insertion of rhomboid minor

medial border of scapular (at spine of scapula)

Origin of rhomboid major

spinous processes of T2 to T5

Insertion of rhomboid major

medial border of scapula (lower 2/3’rds)

Innervation of rhomboid minor and major

dorsal scapular nerve

Action of rhomboid minor and major

adduct and elevates scapula

Blood supply of rhomboid minor and major

dorsal scapular artery

Origin of serratus posterior superior

ligamentum nuchae, spinous processes and supraspinous ligaments of C7 to T3

Insertion of serratus posterior superior

ribs 2 to 5 (upper borders)

Function of serratus posterior superior

respiration (elevate ribs 2-5 during inhalation)

Origin of serratus posterior inferior

spinous processes of T11 to L3 and supraspinous ligaments

Insertion of serratus posterior inferior

upper border of ribs 9-12

Function of