700: Compartments of Forearm

anterior compartment holds

flexors and pronators

anterior compartment supplied by

primarily median nerve, the rest of ulnar nerve

posterior compartment holds

extensors and supinators

posterior compartment all innervated by

radial nerve

superficial layer of flexor pronator compartments

Pronator teres

Flexor carpi radialis

Palmaris longus

Flexor carpi ulnaris

intermediate layer of flexor pronator compartments

flexor digitorum superficialis

deep layer of flexor pronator compartments

Flexor digitorum profundus

Flexor pollicIs longus

Pronator quadratus

In the anterior compartment - median nerve innervates

flexors and pronators

In the anterior compartment - ulnar nerve innervates

flexor carpi ulnaris

flexor digitorum profundus

common flexor tendon comes off of

the medial epicondyle

flexor retinaculum superficial to

median nerve

flexor retinaculum (carpal tunnel) action

pins down flexor tendons

flexor retinaculum (carpal tunnel) attachments / borders

Trapezium

Hook of hamate

Pisiform

Scaphoid

inside the carpal tunnel

median nerve, tendons of flexor digitorum superficialis /profundus, flexor pollicis longus, tendon of flexor carpi radialis

roof of carpal tunnel

flexor retinaculum

tendinous chiasm

flexor digitorum profundus goes through flexor digitorum superficialis

the radial nerve terminal branch has injury will result in

loss of extension and supination

extensor supinator muscles - superficial layer

Brachioradialis – elbow flexor and supinator

Extensor carpi radialis longus

Extensor carpi radialis brevis

Extensor digitorum

Extensor digiti minimi

Extensor carpi ulnaris

extensor supinator muscles - deep layer

Supinator

Abductor pollicis longus

Extensor pollicis brevis

Extensor pollicus longus

Extensor indicis

Superficial radial nerve branch continues to provide cutaneous sensation to

the hand

Deep branch of radial nerve pierces the

supinator to enter posterior compartment

posterior interosseous nerve innervates most of

the extensors of the forearm (ECU, EDM,…

radial nerve innervates

brachioradialis

extensor carpi radials longus

deep radial nerve only innervates

supinator

extensor retinaculum compartment 2

extensor carpi radialis longus

extensor carpi radialis brevis

extensor retinaculum compartment 1

abductor pollicis longus and extensor pollicis brevis

extensor retinaculum compartment 3

extensor pollicis longus

extensor retinaculum compartment 4

extensor digitorum

extensor indicis

(2 tendons)

extensor retinaculum compartment 5

extensor digiti minimi\

(1 tendon)

extensor retinaculum compartment 6

extensor carpi ulnaris

(1 tendon)

dorsal extensor expansion lateral band

interossei and lumbrical

dorsal extensor expansion hood allows

lumbrical grip

The ___ bifurcates to create a tunnel for passage of a deeper forearm muscle?

tendon of the flexor digitorum superficialis