actions of the upper extremity muscles
explains and describes the actions and movements of the muscles.
Prime mover of arm flexion, rotates arm medially, adducts arm.
Prime mover of arm abduction when all its fibers contract simultaneously.
Flexes elbow and supinates forearm
Synergist in forearm flexion stabilizes elbow during rapid flexion and extension.
Pronates forearm; weak flexor of elbow.
Flexor Carpi Radialis
Powerful flexor of the wrist; abducts hand; weak synergist of elbow flexion.
Tenses skin and fascia of palm during hand movements; weak wrist flexor; weak synergist for elbow flexion.
Flexor Carpi Ulnaris
Powerful flexor of wrist; also adducts hand in concert with extensor capi ulnaris; stabilizes wrist during finger extension.
Flexor Digitorum Superficialis
Flexes wrist and middle phalanges of fingers 2-5; the important finger flexor when speed and flexion against resistance are required.
Flexor Pollicis Longus
Flexes distal phalanx of thumb.
Flexor Digitorum Profundus
Flexes distal interphalangeal joints; slow-acting flexor of any or all fingers; assists in flexing wrist.
Extensor Carpi Radialis Longus
Extends wrist in conjunction with the extensor capi ulnaris and abducts wrist in conjunction with the flexor carpi radialis.
Extensor Carpi Radialis Brevis
Extends and Abducts wrist; acts synergistically with extensor carpi radialis longus to steady wrist during finger flexion.
Prime mover of finger extension; extends wrist; can abduct fingers.
Extensor Carpi Ulnaris
Extends wrist in conjunction with the extensor carpi radialis and adducts wrist in conjunction with flexor carpi ulnaris.
Assists biceps brachii to forcibly supinate forearm; works alone in slow supination; antagonist of pronator muscle.
Abductor Pollicis Longus
abducts and extends thumb
Extensor Pollicis brevis/longus
Prime mover of arm extension; powerful arm adductor; medially rotates arm at shoulder.