Transverse head of adductor hallucis

The transverse head of the adductor hallucis is one of two heads of the adductor hallucis muscle located in the deep layer of the plantar aspect of the foot.The transverse head originates from the plantar ligaments of the lateral four metatarsophalangeal joints and the deep transverse metatarsal ligament. Its muscle fibers run transversely across the sole, parallel to the distal transverse metatarsal arch, and converge to insert with the oblique head onto the lateral side of the base of the proximal phalanx of the hallux, as well as the lateral sesamoid bone.

Functionally, the transverse head stabilizes the forefoot and anchors the hallux during propulsion, contributing to maintenance of the transverse arch and assisting in adduction of the great toe. Anatomical studies confirm that the insertion is typically conjoined with the oblique head and the tendon of lateral head of the flexor hallucis brevis, rather than having a separate tendon slip to the proximal phalanx.

• Origin: plantar ligaments of the 3rd, 4th, and 5th metatarsophalangeal joints, deep transverse metatarsal ligament

• Insertion: Lateral side of the base of the proximal phalanx of the great toe, common tendon with the oblique head (often containing a lateral sesamoid bone)

• Innervation: Deep branch of the lateral plantar nerve (S2–S3)

• Blood supply: Lateral plantar artery and plantar arterial arch

• Action: Adducts the great toe toward the second toe

Gray's description: The transverse head (Transversus pedis) is a narrow, flat fasciculus which arises from the plantar metatarsophalangeal ligaments of the third, fourth, and fifth toes (sometimes only from the third and fourth), and from the transverse ligament of the metatarsus. It is inserted into the lateral side of the base of the first phalanx of the great toe, its fibers blending with the tendon of insertion of the oblique head.