Muscles of the posterior compartment of the forearm: identification. F: forearm flexion- most ideal during semi-supination picking up a beer case . F: crosses back of wrist joint- extension of hand radial side- abduction. I: extensor expansion of 2nd-5th digits (webbing behind posterior surface of knuckles) F: cross wrist joint- extension, 2nd-5th digit extension. Only one of them- don"t need to designate depth. ?- flexor carpi ulnaris- o: medial epicondyle anterior muscle. 3 pollicus to thumb (epl, apl, epb), 1 to index (ei) I: proximal radius- coming around laterally and wrapping around front of radius. F: forearm supination- contracts- uncrosses pronated radius supination, contributes to biceps brachii- why its powerful. Helps landmark other structures- identify tiny vessels/nerves in lab. F: hand extension, 2nd digit extension at metacarpophalangeal joint. If something"s wrong w. extensor digitorum- might be able to still see extension. F: thumb abduction- crossing to anterior surface of thumb- contraction causes abduction.