Flexor Hallucis Longus

Description

Flexor Hallucis Longus Stretch Test

FHL Muscle

Medial view of the ankle joint presenting the contents of the tarsal tunnel; tibialis posterior tendon (TP), flexor digitorum longus tendon (FDL), posterior tibial artery (PTA), posterior tibial vein (PTV), tibial nerve (TN) and the tendon of flexor hallucis longus (FHL), deep to the flexor retinaculum (FR). The bifurcation (B) points of the PTA (PTA B) and TN (TN B) are also represented

Names

• Flexor Hallucis Longus
• FHL muscle
• Flexor muscle of the great toe
• Long flexor of the big toe
• Great toe flexor
• Flexor hallucis longus tendon

General

• Flexor muscle of the great toe
• Part of the Deep Posterior Compartment of the Leg
• The tendon navigates the Tarsal Tunnel as it moves to the foot

Origin

• Fibula (distal 2/3, posterior surface)
• Interosseous Membrane of the Leg
• Posterior Intermuscular Septum of leg
• Tibialis Posterior Muscle (fascia)

Anatomic Course

• Muscle belly runs in deep posterior compartment of the leg
• Tendon passes posterior to the ankle, deep to the Achilles Tendon
• Enters fibro-osseous tunnel between talus and calcaneus (retrotalar pulley)
• Courses into plantar foot and crosses the FDL at the Knot of Henry
• Travels between the medial and lateral sesamoids of the first metatarsal head

Insertion

• Base of distal phalanx of great toe

Actions

• Plantar Flexion and Inversion of foot
• Flexion of MTP and IP joints of great toe

Vascular Supply

• Posterior Tibial Artery
• Fibular Artery

Nerve

• Tibial Nerve (S2-S3)

Bursa of the flexor hallucis longus tendon

• Not well described in the medical/ anatomy literature

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Clinical Significance

• Stenosing Tenosynovitis (Dancer's Tendonitis)
• Trigger Toe (Hallux Saltans)
• Acute Compartment Syndrome
• Chronic Exertional Compartment Syndrome

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See Also

• Physical Exam Ankle
• Ankle Anatomy (Main)
• Ankle Pain (Main)

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