Final answer:
The origin of the flexor digitorum superficialis muscle is the medial epicondyle of the humerus, the radius, and the interosseous membrane, while its insertion is into the middle phalanges of the four fingers.
Step-by-step explanation:
The flexor digitorum superficialis is a muscle within the anterior compartment of the forearm that plays a key role in flexing the fingers and the hand at the wrist. Its origin is the humerus bone's medial epicondyle via the common flexor tendon, the anterior surface of the radius, and the radioulnar interosseous membrane. The muscle's insertion points are the middle phalanges of the four fingers. Notably, it does not insert onto the thumb. The flexor digitorum superficialis works to flex the hand as well as the digits at the knuckles, crucial for rapid finger movements such as typing or playing a musical instrument.