Posterior Forearm and Dorsal
Hand
pp. 744- 750, 757- 793
Topics
Extensor Muscles of the Forearm
Radial Nerve
Dorsal Hand
Metacarpophalangeal Joint
Interphalangeal Joint
Extensor Muscles of the Forearm
Extend or abduct/ adduct hand at
wrist joint
– Extensor carpi radialis longus
Lateral supracondylar ridge
Dorsal aspect base of 2nd
metacarpal
Radial nerve
– C6 myotome
Extension/ abduction
– Extensor carpi radialis brevis
Lateral epicondyle of the humerus
Dorsal aspect of base of 3rd
metacarpal
Deep radial nerve
Extension/ abduction
– Extensor carpi ulnaris
Lateral epicondyle of the humerus
– Posterior surface of the
olecranon process
Dorsal aspect of 5th metacarpal
Posterior interosseous nerve
Extensor Muscles of the Forearm
Extend Digits II- V
– Extensor digitorum
Lateral epicondyle of the humerus
Extensor expansions of digits II- V
Posterior interosseous nerve
Extend hand and digits II- V
– Extensor indicis
Posterior surface of the ulna and
interosseous membrane
Extensor expansion of digit II
Posterior interosseous nerve/
– C8 myotome
Extends index finger
– Extensor digiti minimi
Lateral epicondyle of the humerus
Extensor expansion of digit V
Posterior interosseous nerve
Extends digit V
Extensor Muscles of the Forearm
Extend or abduct Digit I
– “Outcropping” muscles
– Abductor pollicis longus
Posterior proximal radius, ulna and
interosseous membrane
Base of 1st metacarpal
Posterior interosseous nerve
Abduct and extend thumb
– Extensor pollicis longus
Posterior surface of middle 1/3 of ulna
and interosseous membrane
Dorsal aspect distal phalanx digit I
Posterior interosseous nerve
Extend digit I
– Extensor pollicis brevis
Posterior surface of distal 1/3 of radius
and interosseous membrane
Dorosal aspect base of proximal
phalanx of thumb
Posterior interosseous nerve
Extend proximal phalanx of digit I
Extensor Muscles of Forearm
Brachioradialis
– Proximal 2/3 of lateral
supracondylar line
– Lateral surface of distal end of the
radius
– Radial nerve
C6 myotome
– Flexion of forearm in midprone
position
Supinator
– Lateral epicondyle of humerus,
radial collateral and annular
ligaments; supinator fossa, crest
of ulna
– Proximal 1/3 of radius
– Deep radial nerve
C8 myotome
– Supinates forearm
Radial Nerve in the Posterior
Forearm
Radial Nerve
– Brachioradialis
– Extensor carpi radialis longus
Superficial Radial Nerve
– Sensory to dorsum of hand
Deep Radial Nerve
– Extensor carpi radialis brevis
– Supinator
Posterior Interosseous Nerve
– Continuation of Deep Radial Nerve
– All Remaining Muscles of the Posterior Compartnment
Dorsal Hand
Extensor retinaculum
Synovial tendon
sheaths
Extensor Expansion
Lateral Hand
Anatomical snuffbox
Radial artery