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Trapezius
- Origin- EOP, medial portion of the superior nuchal line, ligamentum nuchae, SPs of C7 - T12
- Insertion- Lateral portion of clavicle, acromion, spine of scapula (same as origins of deltoid)
- 3 separate muscle bellies
- Upper bilateral- extends head and neck
- Upper unilateral- laterally flexes, rotates head and neck to contralateral side, upwardly rotates scapula, elevates scapula
- Middle trap- Adducts scap, stabilizes scap
- Lower trap- Depresses scap, upwardly rotates
- NR, S
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Rhomboids
- Origins: Major- SPs of T2-T5; Minor- SPs of T1 and C7
- Insertion: medial border of the scapula between the spine and inferior border
- Actions: adduction of the scap (primary), elevation and downward rotation of the scap
- NR; deep to trapezius
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Levator Scapula
- Origin: TVPs of C1 - C4
- Insertion: Medial border of the scapula, between the superior angle and above the spine of the scap
- Actions: Unilaterally- Elevates scap (primary), downwardly rotates, laterally flexes the head and neck, rotates head to same side (ipsilaterally); bilaterally- extends head and neck
- NR; Both- deep at origin and insertion
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Serratus Anterior
- Origin- External surfaces of upper 8 or 9 ribs
- Insertion- Anterior (costal) surface of medial border of the scapula
- (accessible from lateral scap)
- Actions- Abducts scapula, depresses scapula, upwardly rotates scapula, holds medial border of scap against ribcage, may act in forced inspiration
- NR; both- deep to anterior scap
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Pectoralis Minor
- Origin- ribs 3, 4 and 5
- Insertion- Coracoid process of scap
- Actions- Depresses scap, abducts scap, downwardly rotates scap, assists in forced inspiration
- NR; deep
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