Superficial Back Muscles Flashcards
Origin of Trapezius
Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of CVII to TXII
Insertion of Trapezius
Lateral one-third of clavicle, acromion, spine of scapula
Innervation of Trapezius
Motor-accessory nerve [XI]; proprioception-C3 and C4
Function of Trapezius
Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula
Origin of Rhomboid major
Spinous processes of TII to TV
Insertion of Rhomboid major
Medial border of scapula between spine and inferior angle
Innervation of Rhomboid major
Dorsal scapular nerve (C4, C5)
Function of Rhomboid major
Retracts (adducts) and elevates scapula
Origin of Rhomboid minor
Lower portion of ligamentum nuchae, spinous processes of CVII and TI
Insertion of Rhomboid minor
Medial border of scapula at the spine of scapula
Innervation of Rhomboid minor
Dorsal scapular nerve (C4, C5)
Function of Rhomboid minor
Retracts (adducts) and elevates scapula
Origin of Levator scapulae
Transverse processes of CI to CIV
Insertion of Levator scapulae
Upper portion medial border of scapula
Innervation of Levator scapulae
C3 to C4 and dorsal scapular nerve (C4, C5)
Function of Levator scapulae
Elevates scapula
Origin of Serratus anterior
Lateral surfaces of upper 8-9 ribs and deep fascia overlying the related intercostal spaces
Insertion of Serratus anterior
Costal surface of medial border of scapula
Innervation of Serratus anterior
Long thoracic nerve [C5, C6, C7]
Function of Serratus anterior
Protraction and rotation of the scapula; keeps medial border and inferior angle of scapula opposed to thoracic wall
Origin of Teres major
Elongate oval area on the posterior surface of the inferior angle of the scapula
Insertion of Teres major
Medial lip of the intertubercular sulcus on the anterior surface of the humerus
Innervation of Teres major
Lower subscapular nerve [C5, C6, C7]
Function of Teres major
Medial rotation and extension of the arm at the glenohumeral joint
Origin of Teres minor
Upper two-thirds of a flattened strip of bone on the posterior surface of the scapula immediately adjacent to the lateral border of the scapula
Insertion of Teres minor
Inferior facet on the posterior surface of the greater tubercle of the humerus
Innervation of Teres minor
Axillary nerve [C5, C6]
Function of Teres minor
Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint
Origin of Supraspinatus
Medial two-thirds of the supraspinous fossa of the scapula and the deep fascia that covers the muscle
Insertion of Supraspinatus
Most superior facet on the greater tubercle of the humerus
Innervation of Supraspinatus
Suprascapular nerve [C5, C6]
Function of Supraspinatus
Rotator cuff muscle; initiation of abduction of arm to 15° at glenohumeral joint
Origin of Infraspinatus
Medial two-thirds of the infraspinous fossa of the scapula and the deep fascia that covers the muscle
Insertion of Infraspinatus
Middle facet on posterior surface of the greater tubercle of the humerus
Innervation of Infraspinatus
Suprascapular nerve [C5, C6]
Function of Infraspinatus
Rotator cuff muscle; lateral rotation of arm at the glenohumeral joint
Origin of Subscapularis
Medial two-thirds of subscapular fossa
Insertion of Subscapularis
Lesser tubercle of humerus
Innervation of Subscapularis
Upper and lower subscapular nerves [C5, C6, (C7)]
Function of Subscapularis
Rotator cuff muscle; medial rotation of the arm at the glenohumeral joint
Origin of Latissimus dorsi
Spinous processes of TVII to LV and sacrum, iliac crest, ribs X to XII
Insertion of Latissimus dorsi
Floor of intertubercular sulcus of humerus
Innervation of Latissimus dorsi
Thoracodorsal nerve (C6 to C8)
Function of Latissimus dorsi
Extends, adducts, and medially rotates humerus