Extensor Hallucis Longus

Introduction[edit | edit source]

The Extensor hallucis longus (EHL) is a thin muscle, situated between the Tibialis anterior and the Extensor Digitorum Longus[1] in the anterior compartment of the lower leg. It provides the only active extension force to the interphalangeal joint and the primary active extension force to the metatarsophalangeal joint. It has a slightly smaller moment arm for dorsiflexion at the ankle than the anterior tibialis. It has a smaller physiological cross sectional area than either the anterior tibialis or the extensor digitorum longus.[2]

Anatomy[edit | edit source]


 Origin[edit | edit source]


From the middle two quarters of the anterior surface of fibula and the adjacent interosseous membrane .[4]

Insertion[edit | edit source]

EHL passes deep to the extensor retinaculum before inserting at the base of the distal phalanx of the big toe .[4][5]

Nerve Supply[edit | edit source]

Deep peroneal nerve L4 , L5 .[4][5]

Action[edit | edit source]

Extends the metatarsophalangeal and interphalangeal joints of the big toe and assist in the in the inversion of the foot and dorsiflexion of the ankle .[4]

Artery[edit | edit source]

Anterior tibial artery.[6]

Synergists[edit | edit source]

Extensor digitorum longus, Tibialis anterior, Peroneus tertius.[6]

Manual Muscle test[edit | edit source]

Patient position : supine or sitting.

Test : extension of metatarsophalangeal and interphalangeal joints of the big toe.

Pressure : against dorsal surface of distal phalanges of the big toe in the direction of flexion.[4]

Palpation[edit | edit source]


EHL palpation starts at 4:37

Paralysis of EHL[edit | edit source]

In the paralysis of EHL , the action of EHB is dominant, the distal phalanx doesn't extend and the proximal phalanx extend in the direction of adduction.[4]

Effect of Weakness[edit | edit source]

Weakness of EHL decreases extension at the metatarsophalangeal and interphalangeal joints. As it is the only muscle for the extension of interphalangeal joint, decreased dorsiflexion of the great toe is diagnostic for EHL weakness.

During normal locomotion, an individual contacts the ground with the heel of the foot first. The ground reaction force applies a plantarflexion moment to the whole foot, which is resisted by all of the dorsiflexors. Weakness of the EHL diminishes an individual’s ability to control the descent of the medial portion of the foot, particularly the great toe.

Patients with weakness of the extensor hallucis longus also report that the toe tends to fold under the foot when they are pulling on socks or shoes and can cause tripping.[2]

Effect of Tightness[edit | edit source]

Tightness of the EHL pulls the metatarsophalangeal joint of the great toe into extension, which, as in the fingers and thumb, tends to produce flexion at the interphalangeal joint, leading to a claw toe deformity.

Hyperextension of the great toe pulls the plantar plate distally, exposing the metatarsal head to excessive loads and producing pain. Similarly, hyperextension of the metatarsophalangeal joint pulls the interphalangeal joint into the toe box of a shoe, causing pain and calluses, or corns, on the dorsal surface of the interphalangeal joint.

Claw Deformities of the toes :
Claw toe deformities in a foot with sensation are quite painful. Claw deformities in a foot without sensation put the individual at risk of skin breakdown as the result of increased pressure under the metatarsal heads and between the dorsal surfaces of the toes and the shoe.[2]

Claw with words.jpg

Trigger point referral[edit | edit source]

EHL refers pain to the distal aspect of the 1st metatarsal and great toe, as well as the dorsum of the foot. It may reach up the leg as far as the point. These points are located just distal to the junction between the middle and distal thirds of the leg, just anterior to the fibula. The patient may also complain of persistent dorsal foot pain.[8]


Treatment[edit | edit source]

Strengthening[edit | edit source]



Stretching[edit | edit source]


References[edit | edit source]

  1. https://en.wikipedia.org/wiki/Extensor_hallucis_longus_muscle
  2. 2.0 2.1 2.2 Carol A.Oatis . kinesiology the mechanics and pathomechanics of human movement , 2003
  3. Kenhub - Learn Human Anatomy. Extensor Hallucis Longus Muscle - Origin, Insertion, Innervation & Function - Kenhub. Available from: https://www.youtube.com/watch?v=nFa6uiSVYzo [last accessed 27/3/2022]
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Muscles: Testing and Function, with Posture and Pain. fckLRFlorence P,Elizabeth K, Patricia G,Mary M, William A.5th ed.2005.
  5. 5.0 5.1 Moore KL, Dalley AF, Agur A. Clinically oriented anatomy. 7th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2013.
  6. 6.0 6.1 http://thewellnessdigest.com/extensor-hallucis-longus-muscle-anatomy-origin-insertion-action/
  7. Blackriver & Bootsma Education. Muscle Palpation - Tibialis Anterior & Extensor Digitorum Longus & Extensor Hallucis Longus. Available from: https://www.youtube.com/watch?v=72QuqEpzmsQ [last accessed 27/3/2022]
  8. Steven E.Jurch. clinical massage therapy: assessment and treatment of orthopedic conditions,2007.
  9. Carter Physiotherapy. Big Toe Extension. Available from: https://www.youtube.com/watch?v=RiErCxACmWw [last accessed 27/3/2022]
  10. Restore Plus Physical Therapy & Rehabilitation. Toe Extensor Strengthening Exercise. Available from: https://www.youtube.com/watch?v=95ISH9Q3X4w [last accessed 27/3/2022]
  11. Northwest Foot & Ankle. Toe Extensor Stretch with Dr Ray McClanahan. Available from: https://www.youtube.com/watch?v=h2kaEOd3GcI [last accessed 27/3/2022]