Insertion: deltoid tuberosity of humerus
Insertion: lateral 1/3 of clavicle, acromion and spine of scapula
Origin: clavicle and scapula (opposite trapezius)
Origin: transverse processes of C1-C4
Insertion: upper medial border of scapula
Insertion: medial edge of scapula at (minor) and below (major) scapula spine
Innervation: dorsal scapular nerve (C4-5)
Origin: spinous processes of C7 (minor) and T2-5 (major)
Action: powerful abduction of arm beyond 15 degrees
Action: rotates scapula to elevate arm. also elevates. depresses and retracts scapula. extends and rotates head
Innervation: axillary nerve (C5-6)
Origin: midline of back (occipital protuberance and spinous processes of C7-12)
Action: elevates and retracts scapula
Action: elevates scapula
Innervation: C3. 4 and dorsal scapula nerve (C4, 5)
Innervation: cranial nerve XI, C3, C4