Flexor pollicis longus

  • The flexor pollicis longus (or flexor pollicis longus muscle, latin: musculus flexor pollicis longus) is a muscle of the forearm that belongs to the anterior muscle group and is situated in the third or deep layer.

    Origin

    The flexor pollicis longus originates from the anterior surface of the radius and the interosseous membrane.

    Insertion

    Fibers of the flexor pollicis longus end in a flattened tendon that pass through the carpal channel and reach the thumb. The flexor pollicis longus inserts at the base of the distal phalanx of the thumb.

    Action

    The main functions of the flexor pollicis longus are flexion of the phalanges of the first digit and flexion of the hand.

    Innervation

    The flexor pollicis longus is innervated by the median nerve.