| Origin |
Medial third of superior nuchal line; external occipital protruberance, nuchal ligament, and spinous processes of C7 - T12 vertebrae
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| Insertion |
Lateral third of clavicle, acromion, and spine of scapula
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| Action |
Elevates, retracts and rotates scapula; superior fibers elevate, middle fibers retract, and inferior fibers depress scapula; superior and inferior fibers act together in superior rotation of scapula
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| Innervation |
Spinal root of accessory nerve (CN XI) (motor) and cervical nerves (C3 and C4) (pain and proprioception) (XI, C3, C4)
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| Arterial Supply |
Transverse cervical artery
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| Relevant Approaches |
Posterolateral (Costotransversectomy) Approach to Thoracic Spine |
| Relevant Conditions |
 Lateral Scapular Winging |
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