Extensor Digitorum Longus
Description
The extensor digitorum longus (EDL) is 1 of 4 muscles in the anterior compartment of the lower leg. The other muscles in the anterior compartment include: tibialis anterior, extensor hallucis longus, and peroneus (fibularis) tertius. EDL is the most lateral muscle in the anterior compartment[1].
Anatomy
Origin
Most of EDL arises from the anterior surface of the fibula, the upper part of anterior surface of the interosseus membrane, and the lateral tibial condyle.[3]
Insertion
The tendon of EDL passes under the superior and inferior extensor retinaculum at the anterior surface of the ankle joint before reaching it's distal insertion[1].
It divides into four slips that insert into the proximal and distal phalanges of the lateral four digits of the foot - digits 2-5. [3][4]
Nerve
The muscle is innervated by the deep peroneal nerve, a branch of the common peroneal nerve(L4, L5)[3].
Artery
Anterior tibial artery[1]
Function
Extends lateral four digits and dorsiflexes the ankle[1].
Clinical relevance
Extensor digitorum longus tends to be overactive and tight to compensate for an inhibited tibialis anterior. Stretching and myofascial release of the muscle together with activation tibialis anterior is indicated to regain muscle balance and improve functional ankle dorsiflexion.
Assessment
To assess the EDL, toes 2-5 are dorsiflexed against resistance[1].
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Moore KL, Dalley AF, Agur A. Clinically oriented anatomy. 7th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2013.
- ↑ Kenhub - Learn Human Anatomy. Extensor Digitorum Longus Muscle - Origins & Function - Human Anatomy - Kenhub. Available from: https://www.youtube.com/watch?v=8j8nziP2SPU&t=151s [last accessed 26/3/2022]
- ↑ 3.0 3.1 3.2 Keith L. , Anne M. R . Clinically Oriented Anatomy . philidephia : Lippincott Williams & Wilkins.Feb 13, 2013
- ↑ Anatomy next. Extensor digitorium longus. Available from:https://www.anatomynext.com/extensor-digitorum-longus/ (24july 2019)
- ↑ Kenhub - Learn Human Anatomy. Functions of the extensor digitorum longus muscle (preview) - 3D Anatomy - Kenhub. Available from: https://www.youtube.com/watch?v=4WZbUAH5rH8&t=200s [last accessed 26/3/2022]