Adductor Hallucis


Description[edit | edit source]

Adductor hallucis is an intrinsic, two-headed muscle in the sole of the foot. It is one of three muscles in the third layer of the plantar foot muscles. The other two muscles of the third layer of the plantar foot include flexor hallucis brevis and flexor digiti minimi brevis[1].

Anatomy[edit | edit source]

Origin[edit | edit source]

This muscle has two muscular heads, the transverse and oblique heads. The oblique head originates from the bases of the metatarsals 2 to 4; cuboid bone; tendon of fibularis longus and the lateral cuneiform bone[1][2].

The transverse head originates from the plantar ligaments and the deep transverse metatarsal ligaments of metatarsophalangeal (MTP) joints 3 to 5; [1][2].

Insertion[edit | edit source]

The two heads of the adductor hallucis join together before inserting distally on the lateral side of the base of the first digit's proximal phalanx[1]. The distal attachment point joins with the flexor hallucis brevis tendon on the fibular sesamoid as well[3].

Innervation[edit | edit source]

The deep branch of the lateral plantar nerve (S2, S3)[2] from the tibial nerve.

Blood supply[edit | edit source]

Medial plantar artery, plantar arch, lateral plantar artery and plantar metatarsal arteries[2].

Function[edit | edit source]

It adducts and flexes the great toe at the metatarsophalangeal joint and supports the transverse and longitudinal arches[2].

It may be most active during push-off of the gait cycle by stabilizing the transverse arch of the foot and metatarsal heads[1].

Clinical relevance[edit | edit source]

It supports the longitudinal and transverse arch of the foot. It is a key intrinsic muscle of the foot.

Due to the pull on the lateral aspect of the first digit, the adductor hallucis may contribute to hallux valgus deformities[3]. Surgeons have reported that a full surgical release of the distal tendon of the adductor hallucis during bunionectomies can lead to hallux varus[3].

Assessment[edit | edit source]

Adductor hallucis muscle testing can be done by resisting flexion and adduction of the first digit.

[4]

Treatment[edit | edit source]

A traumatic rupture of the adductor hallucis is uncommon but can lead to hallux varus deformities. Barp et al (2018) reported good surgical outcomes in a case study of a 33 year-old male who underwent surgical fixation of the adductor hallucis tendon following a traumatic rupture while pivoting on a barefoot[5]. Other treatments of the adductor hallucis are not well documented.

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 Moore KL, Dalley AF, R. AAM, Moore KL. lower limb. In: Moore clinically oriented anatomy. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2014. p. 610–5.
  2. 2.0 2.1 2.2 2.3 2.4 MD JV. Adductor hallucis muscle [Internet]. Kenhub; 2023 [cited 2023 May 23]. Available from: https://www.kenhub.com/en/library/anatomy/adductor-hallucis-muscle
  3. 3.0 3.1 3.2 Owens S, Thordarson DB. The adductor hallucis revisited. Foot Ankle Int. 2001 Mar;22(3):186-91.
  4. Blackriver & Bootsma Education. Manual Muscle Test and Lengthening - Flexor Hallucis Brevis & Flexor Digiti Min. & Adductor Hallucis. Available from:https://www.youtube.com/watch?v=22zk-EzctQ4 [last accessed 22/1/2022]
  5. Barp EA, Temple EW, Hall JL, Smith HL. Treatment of Hallux Varus After Traumatic Adductor Hallucis Tendon Rupture. J Foot Ankle Surg. 2018 Mar-Apr;57(2):418-420.