Flexor pollicis longus muscle

The flexor pollicis longus muscle is a muscle in the forearm used to flex the distal phalanx (last part) of the thumb.

Origin
The flexor pollicis longus originates from the radius, on the anterior surface below the anterior oblique line and adjacent to the interosseous membrane.

Insertion
The flexor pollicis longus inserts on the base of the distal phalanx of the thumb.

Innervation
The flexor pollicis longus is innervated by the anterior interosseous nerve (C7 and C8).