joined to ulna by interosseus membrane

tuberosity is on proximal anterior shaft

styloid process is distal, attachment for brachioradialis

two:

anterior: contains flexors, radial nerve and artery, ulnar nerve and artery, median nerve and artery.

posterior: contains extensors, posterior interosseus nerve and artery

arranged in three layers

innervated by median and ulnar nerves

4 muscles with same proximal attachment

from median nerve:

pronator teres

flexor carpi radialis

palmaris longus (absent in 13% of people)

from ulnar nerve:

flexor carpus ulnaris

middle compartment

two heads, humeroulnar and radial- median nerve and ulnar artery pass between them

at the other end, it passes through carpal tunnel and connects to the middle phalanges of the 4 fingers

distal tendons have a slit in them that allows passage of the tendons of the flexor digitorum profundus to each of the distal phalanges

median nerve

radial and ular arteries

deep layer

flexes distal phalanges

digits 4&5 innervated by ulnar nerve

digits 1-3 by median nerve

anterior interosseous artery (from ulnar artery)

flexes distal phalanx of thumb

anterior interosseous nerve and artery

between distal radius and distal ulna

anterior interosseous nerve and artery

weak flexor of forearm

radial nerve

extensor carpus and

radialis longus

extend and radial deviate hand

clench fist

radial nerve

extensor carpi and

radialis brevis

extend and radial deviation of hand

deep branch of radial nerve

extend 4 fingers at MCP IP joints

posterior interosseous nerve (from radial)

extend fifth digit at MCP IP joints

posterior interosseous nerve (from radial)

extend and ular deviate hand

clench fist

posterior interosseous nerve (from radial)