A Extend the wrist (radiocarpal joint)Abduct the wrist (radiocarpal joint)Assist to flex the elbow (humeroulnar joint)O Longus: Distal one-third of the lateral supracondylar ridge ofhumerusI Longus: Base of second metacarpalhelps to flex the elbow joint and is active during fist clenching Extensor Carpi Radialis Longus