Flexor pollicis muscle

Flexor Pollicis Longus Muscle

Flexor pollicis longus muscle (shown in red). Image via Gray's Anatomy.

The Flexor Pollicis Longus Muscle is one of the three deep muscles of the anterior compartment of the forearm that plays a crucial role in the flexion of the thumb. It is located in the forearm and extends into the hand, where it allows for the bending and gripping movements of the thumb.

Origin and Insertion

The Flexor Pollicis Longus originates from the middle half of the anterior surface of the radius and the adjacent interosseous membrane. It inserts into the base of the distal phalanx of the thumb.

Innervation

The muscle is innervated by the anterior interosseous nerve, a branch of the median nerve.

Function

The primary function of the Flexor Pollicis Longus is to flex the thumb at all joints, including the carpometacarpal joint, metacarpophalangeal joint, and interphalangeal joint. This allows for the thumb to oppose the other fingers, a key function in the human hand's ability to grasp and manipulate objects.

Clinical Significance

Damage to the Flexor Pollicis Longus can result in a loss of thumb flexion, significantly impacting hand function. This can occur due to nerve injury, tendon injury, or muscle strain.

See Also

• Hand Muscles
• Forearm Muscles
• Median Nerve
• Muscle Anatomy