Upper Extremity Anatomy - Origins, Insertions, Innervations, Actions (OIIA) - Shoulder to Hand Muscles

A vocabulary-style set of flashcards covering major shoulder, arm, forearm, and hand muscles with definitions.

Deltoid

Shoulder muscle with origins on the clavicle, acromion, and spine of the scapula; inserts at the deltoid tuberosity; abducts the arm and can flex/extend the shoulder; innervated by the axillary nerve.

Supraspinatus

Rotator cuff muscle; initiates the first ~15 degrees of abduction and stabilizes the glenohumeral joint; innervated by the suprascapular nerve.

Infraspinatus

Rotator cuff muscle; externally rotates the humerus and stabilizes the GH joint; innervated by the suprascapular nerve.

Teres Minor

Rotator cuff muscle; externally rotates the arm and stabilizes the GH joint; innervated by the axillary nerve.

Subscapularis

Rotator cuff muscle; internally rotates the humerus and stabilizes the GH joint; innervated by subscapular nerves.

Teres Major

Adducts and medially rotates the arm; inserts at the medial lip of the intertubercular sulcus; innervated by the lower subscapular nerve.

Serratus Anterior

Protracts and upwardly rotates the scapula; stabilizes the medial border against the thoracic wall; innervated by the long thoracic nerve.

Trapezius

Muscle of the upper back that elevates, retracts, and depresses the scapula; innervated by CN XI (accessory nerve).

Latissimus Dorsi

Extends, adducts, and medially rotates the humerus; inserts at the intertubercular sulcus; innervated by the thoracodorsal nerve.

Levator Scapulae

Elevates and downwardly rotates the scapula; from cervical transverse processes to the medial border of the scapula; innervated by dorsal scapular nerve and C3-C4.

Rhomboid Major

Retracts and downwardly rotates the scapula; attaches to the medial border; innervated by the dorsal scapular nerve.

Rhomboid Minor

Retracts and downwardly rotates the scapula; near the spine; innervated by the dorsal scapular nerve.

Pectoralis Major

Flexes, adducts, and medially rotates the humerus; clavicular head; inserts at the intertubercular sulcus; innervated by the lateral and medial pectoral nerves.

Pectoralis Minor

Stabilizes the scapula by drawing it anteriorly and downward; originates from ribs 3–5; inserts on the coracoid process; innervated by the medial pectoral nerve.

Subclavius

Depresses and anchors the clavicle; stabilizes the sternoclavicular joint; innervated by the nerve to subclavius.

Biceps Brachii

Elbow flexor; supinates the forearm; short head from the coracoid, long head from the supraglenoid tubercle; inserts on the radial tuberosity; innervated by the musculocutaneous nerve.

Brachialis

Primary elbow flexor; lies on the anterior humerus; inserts on the ulna tuberosity and coronoid process; innervated by the musculocutaneous nerve.

Coracobrachialis

Flexes and adducts the arm; origin from the coracoid process; insertion on the medial humerus; innervated by the musculocutaneous nerve.

Triceps Brachii

Elbow extensor; long head from infraglenoid tubercle; lateral and medial heads from the humerus; inserts on the olecranon; innervated by the radial nerve.

Pronator Quadratus

Pronates the forearm; originates on the ulna, inserts on the radius; innervated by the anterior interosseous branch of the median nerve.

Anconeus

Assists elbow extension; origin at the lateral epicondyle of the humerus; inserts on the olecranon; innervated by the radial nerve.

Supinator

Supinates the forearm; originates on the lateral epicondyle and ulna; inserts on the radius; innervated by the posterior interosseous nerve.

Brachioradialis

Flexes the elbow when the forearm is in a neutral position; origin on the lateral supracondylar ridge; inserts on the distal radius; innervated by the radial nerve.

Pronator Teres

Pronates the forearm and flexes the elbow; originates at the medial epicondyle and coronoid process; inserts on the radius; innervated by the median nerve.

Flexor Carpi Radialis

Flexes and abducts the wrist; originates at the medial epicondyle; inserts on the bases of the 2nd and 3rd metacarpals; innervated by the median nerve.

Palmaris Longus

Weak wrist flexor; tenses the palmar aponeurosis; originates at the medial epicondyle; inserts on the palmar aponeurosis; innervated by the median nerve.

Flexor Carpi Ulnaris

Flexes and adducts the wrist; originates at the medial epicondyle and ulna; inserts on the pisiform, hook of hamate, and base of the 5th metacarpal; innervated by the ulnar nerve.

Extensor Carpi Radialis Longus

Extends the wrist and abducts it (radial deviation); originates on the lateral supracondylar ridge; inserts at the base of the 2nd metacarpal; innervated by the radial nerve.

Extensor Carpi Radialis Brevis

Extends the wrist and causes radial deviation; originates at the lateral epicondyle; inserts on the base of the 3rd metacarpal; innervated by the radial nerve.

Extensor Digitorum

Extends digits 2–5 at the metacarpophalangeal joints; inserts into the extensor expansions; innervated by the posterior interosseous nerve.

Extensor Digit Minimi

Extends the little finger; inserts into the extensor expansion of digit 5; innervated by the posterior interosseous nerve.

Extensor Carpi Ulnaris

Extends and adducts the wrist; originates at the lateral epicondyle; inserts on the base of the 5th metacarpal; innervated by the posterior interosseous nerve.

Abductor Pollicis Longus

Abducts the thumb and extends at the carpometacarpal joint; origins on the ulna, radius, and interosseous membrane; inserts on the base of the 1st metacarpal; innervated by the posterior interosseous nerve.

Extensor Pollicis Brevis

Extends the proximal phalanx of the thumb; originates on the radius and interosseous membrane; inserts on the proximal phalanx of the thumb; innervated by the posterior interosseous nerve.

Extensor Pollicis Longus

Extends the distal phalanx of the thumb; originates on the ulna and interosseous membrane; inserts on the distal phalanx of the thumb; innervated by the posterior interosseous nerve.

Extensor Indicis

Extends the index finger; originates on the ulna and inserts on the extensor expansion of digit 2; innervated by the posterior interosseous nerve.

Abductor Pollicis Brevis

Abducts the thumb; originates from the flexor retinaculum, scaphoid, and trapezium; inserts at the base of the proximal phalanx of the thumb; innervated by the median nerve.

Flexor Pollicis Brevis

Flexes the proximal phalanx of the thumb; has a superficial head (median nerve) and a deep head (ulnar nerve).

Opponens Pollicis

Opposes the thumb; originates from the flexor retinaculum and inserts on the lateral side of the 1st metacarpal; median nerve.

Abductor Digiti Minimi

Abducts the little finger; originates from the pisiform; inserts on the base of the proximal phalanx; innervated by the ulnar nerve.

Flexor Digiti Minimi Brevis

Flexes the proximal phalanx of the little finger; originates from the hook of the hamate and flexor retinaculum; inserts on the base of the proximal phalanx; innervated by the ulnar nerve.

Flexor Digitorum Superficialis

Flexes the middle phalanges of digits 2–5; originates from the medial epicondyle; inserts on the middle phalanges; median nerve.

Flexor Digitorum Profundus

Flexes the distal phalanges of digits 2–5; originates on the ulna; inserts on the distal phalanges; dual innervation: anterior interosseous (median nerve) for the index and middle digits and ulnar nerve for the ring and little digits.

Opponens Digiti Minimi

Opposes the little finger; originates from the hook of the hamate and flexor retinaculum; inserts on the medial border of the 5th metacarpal; innervated by the ulnar nerve.

Flexor Pollicis Longus

Flexes the distal phalanx of the thumb; originates from the interosseous membrane; inserts on the distal phalanx of the thumb; innervated by the anterior interosseous nerve.

Dorsal Interossei

Interosseous muscles that abduct digits away from the middle finger (DAB); between metacarpals; innervated by the ulnar nerve.

Palmar Interossei

Interosseous muscles that adduct digits toward the middle finger (PAD); between metacarpals; innervated by the ulnar nerve.

Adductor Pollicis

Adducts the thumb; has oblique and transverse heads; innervated by the ulnar nerve.