Scapular Region Muscles

Vocabulary flashcards covering the origin, insertion, nerve supply, roots, and actions of the scapular region muscles as presented in Table 3.5.

Deltoid

Origin: Lateral third of clavicle, acromion, spine of scapula; Insertion: Middle of lateral surface of shaft of humerus; Nerve Supply: Axillary nerve; Roots: $C5,6$; Action: Abducts arm; anterior fibers flex and medially rotate arm; posterior fibers extend and laterally rotate arm

Supraspinatus

Origin: Supraspinous fossa of scapula; Insertion: Greater tuberosity of humerus; capsule of shoulder joint; Nerve Supply: Suprascapular nerve; Roots: $C4, 5, 6$; Action: Abducts arm and stabilizes shoulder joint

Infraspinatus

Origin: Infraspinous fossa of scapula; Insertion: Greater tuberosity of humerus; capsule of shoulder joint; Nerve Supply: Suprascapular nerve; Roots: $C4, 5, 6$; Action: Laterally rotates arm and stabilizes shoulder joint

Teres major

Origin: Lower third of lateral border of scapula; Insertion: Medial lip of bicipital groove of humerus; Nerve Supply: Lower subscapular nerve; Roots: $C6,7$; Action: Medially rotates and adducts arm and stabilizes shoulder joint

Teres minor

Origin: Upper two thirds of lateral border of scapula; Insertion: Greater tuberosity of humerus; capsule of shoulder joint; Nerve Supply: Axillary nerve; Roots: $C4, 5, 6$; Action: Laterally rotates arm and stabilizes shoulder joint

Subscapularis

Origin: Subscapular fossa; Insertion: Lesser tuberosity of humerus; Nerve Supply: Upper and lower subscapular nerves; Roots: $C5, 6, 7$; Action: Medially rotates arm and stabilizes shoulder joint