Origin – spinous processes of C7-T1 • Insertion – medial border of scapula • Innervation – dorsal scapular n. • Action – adducts and elevates scapula • Artery – dorsal scapular a. 20
Origin – rib 1 • Insertion – inferior surface of clavicle • Innervation – nerve to subclavius • Action – depress clavicle • Artery – clavicular branch of thoracoacromial artery 9
Origin – ribs 3,4,5 • Insertion – coracoid process • Innervation – medial pectoral nerve • Action – depress shoulder • Artery – pectoral branch of thoracoacromial artery
Origin – clavicle, acromion and spine of scapula • Insertion – deltoid tuberosity of humerus • Innervation – axillary n. • Action • Anterior Part – flexes & medially rotates • Middle Part – abducts arm (15˚–90˚) • Posterior Part – extends & laterally rotates • Artery – posterior circumflex humeral a.
Origin – lower third lateral border of scapula • Insertion – medial lip intertubercular groove • Innervation – lower subscapular n. • Action – medially rotates and adducts arm • Artery – circumflex scapular a.
Origin – transverse processes of C1-C4 • Insertion – medial border of scapula • Innervation – dorsal scapular n. • Action – elevates scapula • Artery – dorsal scapular a
Origin – subscapular fossa of scapula • Insertion – lesser tubercle of humerus • Innervation – upper & lower subscapular nn. • Action – medially rotates arm • Artery – subscapular a.
Origin – 2 heads • clavicular head – anterior surface of medial half of clavicle • sternocostal head – anterior surface of sternum, superior six costal cartilages • Insertion – lateral edge of bicipital groove of humerus • Innervation – medial and lateral pectoral nerves • Action – flexion, adduction, and medial rotation of the arm • Artery – pectoral branch of thoracoacromial artery 6
Origin – occipital, ligamentum nuchae, spinous processes of C7–T12 • Insertion – upper fibers, clavicle; middle & lower fibers, spine & acromion • Innervation – Accessory Nerve, C.N. XI • Action – elevates, depresses, adducts, and rotates scapula • Abducts arm beyond 90˚ (hyperabduction) • Artery – transverse cervical a.
Origin – spinous processes of T2-T5 • Insertion – medial border of scapula • Innervation – dorsal scapular n. • Action – adducts and elevates scapula • Artery – dorsal scapular a. 21
Origin – infraspinous fossa of scapula • Insertion – greater tubercle of humerus • Innervation – suprascapular n. • Action – laterally rotates arm • Artery – suprascapular a. 27
Origin – iliac crest, spinous processes of T6- T12 • Insertion – intertubercular groove • Innervation – thoracodorsal n. • Action – extends, adducts, medially rotates arm • Artery – thoracodorsal a. 18
Origin – ribs 1-8 • Insertion – anterior surface medial border of scapula • Innervation – long thoracic nerve • Action – pulls scapula against back; lateral rotation of scapula; pushing or punching • Artery – thoracodorsal artery, superior thoracic artery, lateral thoracic artery
Origin – supraspinous fossa of scapula • Insertion – greater tubercle of humerus • Innervation – suprascapular n. • Action – abducts arm (0˚–15˚), slight lateral rotation • Artery – suprascapular a. 26
Origin – upper two thirds lateral border of scapula • Insertion – greater tubercle of humerus • Innervation – axillary n. • Action – laterally rotates arm • Artery – circumflex scapular a
