MSK- Shoulder, arm, elbow

chapter 15 & 16

Trapezius (superficial layer)

Innervation: Accessory Nerve (CN XI)

Function:

• Scapular elevation, depression, retraction

• Rotate Glenoid cavity superiorly

Latissimus dorsi (superficial layer)

Innervation: Thoracodorsal N

Function:

• Humerus extension, medial rotation, & adduction

Rhomboids (superficial layer)

Innervation: Dorsal Scapular N

Function:

• Scapular retraction

• Rotate glenoid cavity inferiorly

Teres Major (superficial layer)

Innervation: Lower subscapular nerve (C5)

Function:

• arm adduction & medial rotation

Supraspinatus (deep layer; rotator cuff)

Innervation: Suprascapular N

Function:

• arm abduction (initiate & assist)

Infraspinatus (deep layer; rotator cuff)

Innervation: Suprascapular N

Function:

• laterally rotate arm

Teres Minor (deep layer; rotator cuff)

Innervation: Axillary N

Function: laterally rotate arm

Subscapularis (Deep layer; rotator cuff)

Innervation: U/L Subscapularis Ns

Function: arm medial rotation

Pectorals: Pectoralis Major

Innervation: Lat./Med. Pectoral N

Function: Arm flexion + Adduction

Pectorals: Pectoralis Minor

Innervation: Medial Pectoral N

Function: Scapular protraction + Stabilization

Pectorals: Serratus Anterior

Innervation: Long Thoracic N

Function: Protract + Stabilize scapula

(same as pec. minor)

Deltoid

Innervation: Axillary N

Function: Arm Flexion, Extension, Abduction

Biceps Brachii (arm flexors)

Innervation: Musculocutaneous N

Function: supination (tendon), minor flexion (aponeurosis)

short head: attaches to coracoid process

long head: attaches to humerus

Coracobrachialis (arm flexor)

Innervation: Musculocutaneous N

Function: arm flexion

note: deep to biceps brachii; attaches to coracoid process

Brachialis (arm flexor)

Innervation: Musculocutaneous N

Function: flex forearm (bottom arm part)

Triceps (Arm extensors)

Innervation: Radial N

Function: arm extension (long head), forearm extension (both heads)

Bones of the elbow

Forearm Flexors (Superficial layer): Pronator Teres

Innervation: Median N

Function: Pronation

Forearm Flexors (Superficial layer): Flexor carpi radialis

Innervation: Median N

Function: Abduct (radial deviation) + Flex wrist

Forearm Flexors (Superficial layer): Palmaris Longus

Innervation: Median N

Function: Tense Palmar Skin

Forearm Flexors (Superficial layer): Flexor Carpi Ulnaris

Innervation: Ulnar N

Function: Adduct (ulnar deviation) & Flex Wrist

Forearm Flexors (Superficial layer): Brachioradialis

Innervation: Radial N

Function: Flex elbow

Forearm Flexors (middle layer): Flexor Digitorium Superficialis

Innervation: Median N

Function: PIP Flexion

Forearm Flexors (deep layer): Flexor Digitorium Profundus

Innervation: Ulnar N

Function: DIP Flexion

Forearm Flexors (deep layer): Pronator Quadratus

Innervation: Median N

Function: forearm pronation

Forearm Extensors: Supinator

Innervation: Radial N

Function: supination

Forearm Extensors: Extensor Carpi Radialis

Innervation: Radial N

Function: Abduct + Extend Wrist

Forearm Extensors: Extensor Digitorium & Extensor Digiti Minimi

Innervation: Radial N

Function: Extend digits @MCP Joint

Forearm Extensors: Extensor Carpi Ulnaris

Innervation: Radial N

Function: Adduct + Extend Wrist

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Outcropping Muscles: Abductor Pollicis Longus

Innervation: Radial N

Function: Abduct thumb @ CMC

Outcropping Muscles: Extensor Pollicis Longus

Innervation: Radial N

Function: Extend @MCP, CMC, IP joints

Outcropping Muscles: Extensor Pollicis Brevis

Innervation: Radial N

Function: Extend @ MCP + CMC joints

Outcropping Muscles: Extensor Indicis

Innervation: Radial N

Function: Extend 2nd Digit