Pectoral / Scapular Region As & Is

Pectoralis major action (3)

Shoulder adduction, medial rotation, and extension from full flexion

Pec major clavicular head assists:

Shoulder flexion

Pec major sternal head assists:

Shoulder depression

Pectoralis minor action (2)

Scapular stabilization (via depression), protraction (toward thoracic wall)

Subclavius action

Stabilization and control of clavicle during shoulder movement

Serratus anterior action

Scapular protract and stabilization

Serratus anterior lower fibers assist:

Upward rotation of scapula at AC and SC joints

Trapezius actions (upper)

Scapular elevation and upward rotation

Trapezius unilateral upper fibers action

Ipsalateral cervical lateral flexion, contralateral cervical rotation

Trapezius bilateral upper fibers action

Cervical extension

Trapezius middle fibers action

Scapular retraction

Trapezius lower fibers action

Scapular depression, scapular upward rotation

Latissimus dorsi action

Shoulder extension / adduction / medial rotation, scapular depression, scapular downward rotation

levator scapulae action

Scapular elevation and downward rotation

Rhomboid minor action

Scapular retraction and downward rotation, fixes medial border of scapula to thoracic wall

Rhomboid major action

Scapular retraction and downward rotation, (fixes medial border of scapula to thoracic wall)

Deltoid action (anterior, middle, posterior fibers)

Shoulder flexion and medial rotation; shoulder abduction; shoulder extension and lateral rotation

Supraspinatus action

Initiates and assists deltoid in arm abduction, stabilizes humerus in glenoid fossa

Infraspinatus action

Shoulder lateral rotation, stabilizes humerus in glenoid fossa

Teres minor action

Shoulder lateral rotation, stabilizes humerus in glenoid fossa

Teres major action

Shoulder adduction and medial rotation

Subscapularis action

Shoulder medial rotation, stabilizes humerus in glenoid fossa

Pectoralis major innervation (clavicular head)

Lateral pectoral (C5, C6)

Pectoralis major innervation (sternal head)

Medial pectoral (C7, C8, T1)

Pectoralis minor innervation

Medial pectoral (C8, T1)

Subclavius innervation

Subclavian (C5, C6)

Serratus anterior innervation

Long thoracic (C5, C6, C7)

Trapezius innervation

CN XI, spinal accessory, (C2, C3, C4)

Latissimus dorsi innervation

Thoracodorsal (C6, C7, C8)

Levator scapulae innervation

Dorsal scapular (C5), C3, C4

Rhomboid major innervation

Dorsal scapular (C4-C5)

Rhomboid minor innervation

Dorsal scapular (C4-C5)

Deltoid innervation

Axillary (C5, C6)

Supraspinatus innervation

Suprascapular (C5, C6)

Infraspinatus innervation

Suprascapular (C5, C6)

Teres minor innervation

Axillary (C5, C6)

Teres major innervation

Lower subscapular (C5, C6, C7)

Subscapularis innervation

Upper and lower subscapular nerves (C5, C6, C7)

Biceps brachii innervation

Musculocutaneous (C5, C6)

Coracobrachialis innervation

Musculocutaneous (C5, C6)

Brachialis innervation

Musculocutaneous (C5, C6, some lateral fibers radial nerve / C7)

Triceps brachii innervation

Radial (C6, C7, C8)