Final answer:
In very general terms, the muscles of the superficial posterior compartment of the forearm function primarily to extend the wrist and fingers, whereas the muscles of the deep layer are involved in more precise movements, such as the extension of the thumb and individual finger movements.
Step-by-step explanation:
In very general terms, the muscles of the superficial posterior compartment of the forearm function primarily to extend the wrist and fingers, whereas the muscles of the deep layer are involved in more precise movements, such as the extension of the thumb and individual finger movements.
The muscles in the superficial posterior compartment, which originate on the humerus, include the extensor radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris. In contrast, the muscles of the deep posterior compartment, which originate on the radius and ulna, include the abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus. These deep layer muscles are crucial for the fine motor skills required in actions like gripping and manipulating objects.