Variation of Flexor pollicis longus muscle (Gantzer’s muscle) - A Rare Variation

Flexor Pollicis longus is one of the deep muscles of the anterior compartment of the forearm, responsible for the flexion of the thumb at the interphalangeal joint. By originating from the anterior surface of radius and the adjacent interosseous membrane, this muscle inserts into the base of the distal phalanx of the thumb. However, anatomical variations in its morphology, including presence of extra head, commonly referred to as the Gantzer’s muscle are not common. This study presents a rare case of additional head of the flexor pollicis longus muscle arising from the ulna.