Final answer:
The common action of the muscles in the anterior compartment of the forearm that moves the wrist or digits is flexion. These muscles primarily perform bending movements necessary for various daily activities.
Step-by-step explanation:
The action that all five of the muscles we study in the anterior compartment of the forearm have in common, and that moves the wrist or the digits, is flexion. These muscles include the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, and, in the deeper layer, the flexor pollicis longus and flexor digitorum profundus. Their primary function is to facilitate bending motions, such as flexing the hand at the wrist and curling the fingers into a fist, necessary for tasks like typing, playing musical instruments, and gripping objects.