Muscle

Anterior deltoid

Flexes and internally rotates the glenohumeral joint (GHJ).

Middle deltoid

Adducts the glenohumeral joint (GHJ).

Posterior deltoid

Extends and externally rotates the glenohumeral joint (GHJ).

Supraspinatus

Initiates and assists in abduction of the humerus with deltoids.

Infraspinatus and teres minor

Externally rotate the glenohumeral joint (GHJ).

Subscapularis

Internally rotates and adducts the glenohumeral joint (GHJ).

Teres major and latissimus dorsi

Adduct, extend, and internally rotate the glenohumeral joint (GHJ).

Upper trapezius

Elevates the scapula.

Middle trapezius

Retracts the scapula.

Lower trapezius

Depresses the scapula.

Levator scapulae

Elevates scapula and tilts glenoid cavity; fixes scapula and rotates it to depress glenoid cavity.

Pectoralis major

Adducts, horizontally adducts, and internally rotates the glenohumeral joint (GHJ).

Pectoralis minor

Draws scapula inferiorly and anteriorly for stabilization.

Subclavius

Depresses the clavicle.

Serratus anterior

Protracts scapula and holds it to the thoracic wall.

Biceps brachii

Short head flexes elbow joint; long head flexes elbow joint and supinates elbow.

Brachialis

Flexes elbow joint; main elbow flexor with forearm pronated.

Coracobrachialis

Flexes and adducts the glenohumeral joint (GHJ).

Triceps brachii long head

Extends elbow and glenohumeral joint (GHJ).

Triceps brachii medial and short heads

Extend the elbow.

Anconeus

Extends the elbow.

Brachioradialis

Relatively weak elbow flexor; main elbow flexor in neutral/50% pronation.

Extensor carpi radialis longus and brevis

Extend wrist and radially deviate.

Extensor digitorum

Extends wrist and 2-5th digits.

Extensor digiti minimi

Extends wrist and 5th finger.

Extensor carpi ulnaris

Extends and ulnar deviates wrist.

Supinator

Supinates forearm.

Abductor pollicis longus

Extends wrist and thumb; abducts thumb.

Extensor pollicis brevis

Extends wrist; extends proximal phalanx of thumb.

Extensor pollicis longus

Extends wrist and distal phalanx of thumb.

Extensor indicis

Extends wrist and 2nd finger.

Pronator teres

Pronates and flexes elbow joint.

Flexor carpi radialis

Flexes and radially deviates hand.

Palmaris longus

Flexes hand.

Flexor carpi ulnaris

Flexes and ulnar deviates hand.

Flexor digitorum superficialis

Flexes wrist, MCP, and PIP joints.

Flexor pollicis longus

Flexes wrist and distal interphalangeal (DIP) joints of 2-5th digits.

Pronator quadratus

Pronates forearm.

Masseter

Elevates and protrudes mandible.

Temporalis

Elevates and retracts temporomandibular joint (TMJ).

Lateral pterygoid

Bilaterally protrudes mandible; unilaterally contralaterally deviates mandible.

Medial pterygoid

Bilaterally elevates and protrudes mandible; unilaterally ipsilaterally laterally deviates mandible.

Sternocleidomastoid

Unilaterally performs ipsilateral flexion and contralateral head rotation; bilaterally extends neck at AOJ and flexes cervical spine.

Longus colli, longus capitis, rectus capitis

Bilaterally flex neck anteriorly; unilaterally flex neck ipsilaterally.

Anterior and middle scalene

Flex neck ipsilaterally; elevate first rib during forced inspiration.

Splenius capitis

Bilaterally extends neck; unilaterally performs lateral ipsilateral flexion and rotation of

Anterior Deltoid

A muscle that flexes and internally rotates the glenohumeral joint (GHJ).

Middle

The central point or position in a range or series.