[6] The ulnar collateral ligament of elbow joint gives its origin to part of this muscle.

Four long tendons come off this muscle near the wrist and travel through the carpal tunnel formed by the flexor retinaculum.

The tendons attach to the anterior margins on the bases of the intermediate phalanges of the four fingers.

The Flexor digitorium superficialis muscle is innervated by the median nerve (C7, C8, T1).

To test flexor digitorum superficialis, one finger is flexed at the proximal interphalangeal joint against resistance, while the remaining three fingers are held fully extended (to inactivate flexor digitorum profundus).