Anatomy Atlas

Tibial nerve

Nervus tibialis
NerveHigh-yielddraftNeuroMSK

Larger terminal branch of the sciatic nerve, running through the popliteal fossa and deep posterior leg to the sole. It supplies the plantarflexors and inverters and the skin of the sole, and is compressed in the tarsal tunnel.

Core anatomy

Location

Center of the popliteal fossa, the deep posterior compartment of the leg, then behind the medial malleolus into the sole.

Root values

L4–S3.

Origin

Sciatic nerve, at the apex of the popliteal fossa

Course

Descends vertically through the popliteal fossa (the most superficial of the three main structures there: nerve, vein, artery), passes deep to the soleus arch, runs in the deep posterior compartment with the posterior tibial vessels, and passes behind the medial malleolus under the flexor retinaculum (tarsal tunnel), dividing into the medial and lateral plantar nerves.

Branches
  • Muscular: gastrocnemius, soleus, plantaris, popliteus (triceps surae and calcaneal tendon); tibialis posterior, flexor digitorum longus, flexor hallucis longus
  • Medial sural cutaneous nerve → joins the fibular communicating branch to form the sural nerve (lateral foot and heel)
  • Medial calcaneal branches (heel)
  • Medial and lateral plantar nerves: intrinsic foot muscles and the skin of the sole
Motor

Plantarflexion, inversion (tibialis posterior), toe flexion and the intrinsic muscles of the sole; also knee flexion (gastrocnemius, popliteus).

Sensory

Sole of the foot (plantar nerves), heel (calcaneal branches), lateral foot (sural nerve, with a fibular contribution).

Relations

Tarsal tunnel contents, anterior to posterior: tibialis posterior, flexor digitorum longus, posterior tibial artery and veins, tibial nerve, flexor hallucis longus ("Tom, Dick And Very Nervous Harry").

Muscles innervated

Other structures innervated

Found in

Mentioned in

Generated automatically from links in other entries.

Compartments of the leg (cross-section)Mid-leg cross-section. The tibia lies anteromedially and the fibula laterally, joined by the interosseous membrane. Anterior and posterior intermuscular septa and the transverse intermuscular septum divide the leg into anterior, lateral, deep posterior and superficial posterior compartments, each with its own nerve.TibiaFibulaGreat saphenous v.Small saphenous v. + sural n.Anterior ↑ · medial on the left (schematic)AnteriorTibialis anterior, EHL, EDL, fibularis tertiusDeep fibular n. · anterior tibial a.Dorsiflexion, toe extensionLateralFibularis longus and brevisSuperficial fibular n.EversionDeep posteriorTibialis posterior, FDL, FHLTibial n. · posterior tibial and fibular aa.Inversion, toe flexionSuperficial posteriorGastrocnemius, soleus, plantarisBranches of the tibial n.Plantarflexionnervearteryvein

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Compartments of the leg. Schematic mid-leg cross-section: four compartments separated by bone, the interosseous membrane and intermuscular septa, each with its own nerve. Compartment syndrome most often affects the anterior compartment.
Original schematic, created for this atlas.
Lower limb dermatomes (anterior view) and key musclesL1 over the groin and upper thigh; L2 the upper anterior thigh; L3 the lower anterior thigh and knee; L4 the medial leg and medial malleolus; L5 the lateral leg and dorsum of the foot including the great toe; S1 the lateral edge of the foot and little toe. Table: L2 hip flexion; L3 knee extension; L4 ankle dorsiflexion and patellar reflex; L5 great toe extension; S1 plantarflexion and ankle reflex.L1L2L3L4L5S1LateralMedial (great toe)ASIA key sensory point (S1: lateral heel)RootKey muscle actionReflexL2Hip flexion—L3Knee extension—L4Ankle dorsiflexionPatellar (L3–L4)L5Great toe extension—S1Ankle plantarflexionAnkle (Achilles)Foot drop with weak inversion → L5 root;with normal inversion → common fibular nerve.Maps differ between sources; neighbours overlap.

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Lower limb dermatomes and key muscles. Right lower limb, anterior view (medial = your right). Dots are ASIA key sensory points; the table gives the key muscle action and reflex for each root. Dermatome maps differ between sources.
Original schematic, created for this atlas.
Sole of the foot showing the medial and lateral plantar nerves, terminal branches of the tibial nerve
The medial and lateral plantar nerves, terminal branches of the tibial nerve.
Henry Vandyke Carter, Gray's Anatomy of the Human Body, 20th ed. (1918), Fig. 833. Source · Public domain (Public domain in the US: published before January 1, 1931 (per Wikimedia Commons))
Posterior view showing the sciatic nerve dividing into the tibial and common fibular (peroneal) nerves, with the gluteal nerves
The tibial nerve descending through the popliteal fossa and calf.
Henry Vandyke Carter, Gray's Anatomy of the Human Body, 20th ed. (1918), Fig. 832. Source · Public domain (Public domain in the US: published before January 1, 1931 (per Wikimedia Commons))

Clinical correlations

Tarsal tunnel syndrome PANCE

Mechanism / lesion

Compression under the flexor retinaculum behind the medial malleolus (ganglia, varicosities, tenosynovitis, flat foot, trauma).

Classic presentation

Burning pain, tingling and numbness of the sole and toes, worse with standing, walking or at night; Tinel sign behind the medial malleolus; the heel may be spared (calcaneal branches arise proximally).

Tibial nerve injury

Mechanism / lesion

Posterior knee dislocation, popliteal trauma, deep posterior compartment syndrome.

Classic presentation

Loss of plantarflexion and inversion, inability to stand on tiptoe, loss of the ankle reflex, numbness of the sole (risk of ulcers), a calcaneovalgus foot.

Sural nerve biopsy and grafts

Mechanism / lesion

The sural nerve is purely sensory and easily found beside the small saphenous vein behind the lateral malleolus.

Classic presentation

Used for nerve biopsy (e.g. vasculitic neuropathy) and as a nerve graft; leaves a numb patch on the lateral foot.

High-yield PANCE pearls

  • Tibial nerve: plantarflexion + inversion, ankle reflex (S1), sole sensation.
  • Burning sole pain with Tinel sign behind the medial malleolus → tarsal tunnel syndrome.
  • Can't stand on tiptoe → tibial nerve (or S1/Achilles) problem.

Imaging anatomy

MRI

Masses, ganglia or varicosities in the tarsal tunnel; MR neurography.

Ultrasound

Shows compressive lesions in the tarsal tunnel and the nerve in the popliteal fossa.

Physical exam

Surface landmarks

The tibial nerve and posterior tibial pulse lie midway between the medial malleolus and the Achilles tendon.

Palpation

Tinel sign over the tarsal tunnel.

Strength / function testing

Plantarflexion (tiptoe standing), inversion, toe flexion; ankle reflex (S1); sensation of the sole and heel. Nerve conduction studies confirm tarsal tunnel syndrome.

Self-quiz

Q1.

A 50-year-old runner has burning pain and numbness on the sole of his left foot, worse at night. Tapping behind the medial malleolus reproduces the symptoms. Which nerve is compressed?

Show answer

C

Tarsal tunnel syndrome is compression of the tibial nerve (or its plantar branches) under the flexor retinaculum behind the medial malleolus, causing burning and numbness of the sole with a positive Tinel sign.

Q2.

A lesion of the tibial nerve in the popliteal fossa would cause loss of which movement?

Show answer

C

The tibial nerve supplies the posterior leg muscles — plantarflexion (triceps surae) and inversion (tibialis posterior) — and the sole. Dorsiflexion and eversion are fibular nerve functions.

Q3.

Which structure is the most posterior in the tarsal tunnel behind the medial malleolus?

Show answer

E

From anterior to posterior: Tibialis posterior, flexor Digitorum longus, posterior tibial Artery and Veins, tibial Nerve, flexor Hallucis longus ("Tom, Dick And Very Nervous Harry").

Q4.

A purely sensory nerve, found beside the small saphenous vein behind the lateral malleolus, is commonly used for nerve biopsy. Which nerve is it?

Show answer

C

The sural nerve (formed by the medial sural cutaneous branch of the tibial nerve and the fibular communicating branch) is purely sensory to the lateral foot and heel, so it is used for biopsy (e.g. vasculitic neuropathy) and as a nerve graft, leaving only a numb patch.

Q5.

In tarsal tunnel syndrome, sensation over the heel is often preserved. Why?

Show answer

B

The medial calcaneal branches of the tibial nerve arise before it passes under the flexor retinaculum, so heel sensation can be spared while the sole and toes (medial and lateral plantar nerves) are numb.

Flashcards

See also