Arm, Elbow, Wrist Muscles

Deltoid proximal attachment

lateral 1/3 of clavicle, acromion, spine of scapula

Deltoid distal attachment

deltoid tuberosity of humerus

Deltoid innervation

axillary

Deltoid actions

shoulder abduction, flexion/extension, IR/ER (anterior/posterior)

Biceps brachii long head proximal attachment

supraglenoid tubercle of scapula

Biceps brachii short head proximal attachment

tip of coracoid process of scapula

Biceps brachii distal attachment

radial tuberosity, fascia of forearm via bicipital aponeurosis

Biceps brachii innervation

musculocutaneous

Biceps brachii actions

flex, supinate forearm, short head resists humeral dislocation

Coracobrachialis proximal attachment

tip of coracoid process of scapula

Coracobrachialis distal attachment

middle 1/3 of medial surface of humerus

Coracobrachialis innervation

musculocutaneous

Coracobrachialis actions

flex, adduct arm

Brachialis proximal attachment

distal 1/2 of anterior humerus

Brachialis distal attachment

coronoid process, ulnar tuberosity

Brachialis innervation

musculocutaneous, radial

Brachialis action

main flexor, flexes forearm in all positions

Triceps brachii long head proximal attachment/origin

infraglenoid tubercle of the scapula

Triceps brachii lateral head proximal attachment/origin

posterior humerus superior to radial groove

Triceps brachii medial head proximal attachment/origin

posterior humerus inferior to radial groove

Triceps brachii distal attachment/insertion

proximal end of olecranon process of ulna, fascia of forearm

Triceps brachii innervation

radial

Triceps brachii action

main extensor of forearm, long head steadies abducted humerus

Anconeus proximal attachment

lateral epicondyle of humerus

Anconeus distal attachment

lateral surface of olecranon, superior part of posterior surface of ulna

Anconeus innervation

radial

Anconeus action

extend forearm, stabilize elbow joint, abduct ulna during pronation

Which muscles are in the superficial anterior compartment?

pronator teres (PT), flexor carpi radialis (FCR), palmaris longus (PL), flexor carpi ulnaris (FCU)

PT humeral head origin

medial epicondyle of humerus

PT ulnar head origin

coronoid process of ulna

PT insertion

middle lateral shaft of radius

PT innervation

median

PT actions

flexes, pronates forearm

FCR origin

medial epicondyle of humerus

FCR insertion

base of 2nd MTC

FCR innervation

median

FCR actions

wrist flexion, radial deviation

PL origin

medial epicondyle of humerus

PL insertion

apex of plantar aponeurosis, distal 1/2 of flexor retinaculum

PL innervation

median

PL actions

wrist flexion, tighten palmar aponeurosis

FCU humeral head origin

medial epicondyle

FCU ulnar head origin

olecranon, posterior border of ulna

FCU insertion

pisiform, hook of hamate, 5th MTC

FCU innervation

ulnar

FCU actions

wrist flexion, ulnar deviation

Which muscles are in the intermediate anterior compartment?

flexor digitorum superficialis (FDS)

FDS humero-ulnar head origin

medial epicondyle

FDS radial head origin

superior 1/2 of anterior border of radius

FDS insertion

middle phalnges of digits 2-5

FDS innervation

median

FDS actions

MCP, PIP flexion

Which muscles are in the deep anterior compartment?

flexor digitorum profundus (FDP), flexor pollicis longus (FPL), pronator quadratus (PQ)

FDP origin

proximal 3/4 of medial/anterior ulna, interosseous membrane

FDP insertion

base of distal phalanges of medial 4 digits (travels through Camper’s chiasm)

FDP innervation

digits 2-3: median, digits 4-5: ulnar

FDP actions

flex DIP

FPL origin

anterior radius, interosseous membrane

FPL insertion

base of distal phalanx of thumb

FPL innervation

median

FPL actions

flexes all thumb joints

PQ origin

distal 1/4 of anterior ulna

PQ insertion

distal 1/4 of anterior radius

PQ innervation

median

PQ actions

pronation, hold radius and ulna together

Which muscles are in the superficial posterior compartment?

brachioradialis (BR), extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum communis (EDC), extensor digiti minimi (EDM), extensor carpi ulnaris (ECU)

BR origin

proximal 2/3 of supracondylar ridge of humerus

BR insertion

lateral distal end of of radius proximal to styloid

BR innervation

radial

BR actions

flex elbow when elbow is in neutral

ECRL origin

lateral supracondylar ridge of humerus

ECRL insertion

dorsal base of 2nd MTC

ECRL innervation

radial

ECRL actions

wrist extension, abduction

ECRB origin

lateral epicondyle of humerus

ECRB insertion

dorsal base of 3rd MTC

ECRB innervation

radial

ECRB actions

wrist extension, abduction

EDC origin

lateral epicondyle of humerus

EDC insertion

extensor hood (triangle shaped CT, base of dorsal middle/distal phalanges of medial 4 fingers)

EDC innervation

radial

EDC actions

MCP extension

EDM origin

lateral epicondyle of humerus

EDM insertion

extensor expansion of 5th digit

EDM innervation

radial

EDM actions

5th digit MCP and IP extension

ECU origin

lateral epicondyle, posterior ulna

ECU insertion

dorsal base of 5th MTC

ECU innervation

radial

ECU action

wrist extension, ulnar deviation

Which muscles are the deep posterior compartment?

abductor pollicis longus (APL), extensor pollicis brevis (EPB), extensor indicis (EI), extensor pollicis longus (EPL), supinator (S)

APL origin

posterior proximal 1/2 of radius, ulna, interosseous membrane

APL insertion

base of 1st MTC

APL innervation

radial

APL actions

thumb abduction, MCP extension

EPB origin

posterior distal 1/3 of radius, interosseous membrane

EPB insertion

dorsal base of proximal phalanx of thumb

EPB innervation

radial

EPB actions

extension of MCP, CMC thumb

EPL origin

posterior middle 1/3 of ulna, interosseous membrane