Flexor pollicis longus
Arms
Deep muscle — it lies under other muscles. X-ray makes the muscles over it see-through.
- Origin
- Front of the radius and the interosseous membrane
- Insertion
- Base of the distal phalanx of the thumb
- Action
- Flexes the thumb, including its tip joint
- Nerve supply
- Anterior interosseous nerve (median nerve, C7–C8)
The deep forearm muscle that bends the tip of the thumb. It is the only muscle that can do so, which makes it important for pinching and gripping.
Flexor pollicis longus anatomy page →