ANATOMY OF THE LEG

By:Dr: Mohammed Faez

The Leg

• It is the portion between the knee and the ankle.

• It is comprised of two long bones (tibia –medially and fibula -laterally).

The Leg

The leg is divided into four compartments

• Anterior compartment• Lateral compartment• (Superficial) Posterior

compartment• Deep posterior

compartment

Anterior Compartment

Anterior compartment contains the muscles that dorsiflex the ankle and extend the toes.

• Contains Anterior Tibial Nerve

• Contains Anterior Tibial Artery.

Anterior Compartment

Blood supply:Anterior tibial artery.

Innervation:Deep peroneal (fibular) nerve.

Anterior Compartment

The muscles of the compartment are:

• Tibialis anterior• Extensor hallucis longus• Extensor digitorum

longus• Fibularis tertius

(peroneus tertius)

Anterior Compartment

TA:Tibialis anterior

EDL:Extensor digitorum longus

EHL:Extensor hallucis longus

PT:Peroneus tertius

Anterior Compartment

Tibialis anterior (TA) • Origin -lateral condyle of

tibia, upper half/lateral surface of tibia, interosseous membrane

• Insertion - medial cuneiform, base of 1st metatarsal

• Nerve - deep fibular (peroneal) (L4-5)

• Action - ankle dorsiflexion, forefoot inversion

Anterior CompartmentExtensor Digitorum Longus (EDL)• Origin - lateral condyle of

tibia, ant surface of fibula, interosseous membrane

• Insertion - dorsum of base of middle phalanx, dorsum of base of distal phalanx

• Nerve - deep fibular (peroneal) (L5-S1)

• Action - extension of toes, dorsiflexion of ankle

Anterior Compartment

Extensor Hallucis Longus (EHL) • Origin - middle ½ of ant

fibula, IM• Insertion - distal phalanx of

the great toe• Nerve - deep fibular

(peroneal) (L5-S1)• Action - extend the great

toe, dorsiflex ankle

Anterior Compartment

Fibularis (Peroneus) Tertius • Origin - distal 1/3 ant fibula,

interosseous membrane• Insertion - dorsum shaft of

5th metatarsal• Nerve - deep fibular

(peroneal) (L5-S1)• Action - forefoot eversion,

weak ankle dorsiflexion

Lateral Compartment

Lateral compartment contains the muscles that Everters of the foot (turns foot outward)

Contains the superficial peroneal nerve

Lateral Compartment

Blood supply:No major arteries in lateral compartment.

Muscular branches arise from the peroneal artery (Branch of posterior tibial).

Nerve supply:Superficial peroneal (fibular) nerve

Lateral Compartment

Muscles:• Peroneus Longus• Peroneus Brevis

Lateral Compartment

Fibularis (Peroneus) Longus (FL)• Origin - head, upper 2/3 lateral surface

of fibulaIts tendon courses behind lateral malleolus, underneath the fibular trochlea, and lies in the groove in the cuboid bone before going to its place of insertion

• Insertion - inferolateral surface of medial cuneiform ,1st metatarsal on its inferior surface

• Nerve - superficial fibular (peroneal) (L5-S1)

• Action - forefoot eversion, ankle plantar flexion

Lateral Compartment

Fibularis (Peroneus) Brevis (FB)

• Origin - lower 2/3 lateral fibulaCourses behind lateral malleolus and underneath the fibular trochlea

• Insertion - tuberosity on base of 5th metatarsal

• Nerve - superficial fibular (peroneal) (L5-S1)

• Action - forefoot eversion, ankle plantar flexion

(Superficial) Posterior compartment

Posterior compartment contains the plantar flexors muscles.

Contains:• Short saphenous vein • Peroneal communicating

branch of the common peroneal nerve

• Medial cutaneous nerve of the calf

• Sural nerve

(Superficial) Posterior compartment

Innervation:Tibial nerve.

(Superficial) Posterior compartment

Muscles:• Gastrocnemius • Plantaris • Soleus

(Superficial) Posterior compartment

Gastrocnemius • Origin – medial and

lateral condyles of femur• Insertion –Achilles

tendon to calcaneum • Nerve -Tibial nerve• Action – Plantar flexes

foot; flexes leg• Blood supply:

The popliteal artery

(Superficial) Posterior compartment

Plantaris• Origin – lateral

supracondylar ridge of femur

• Insertion – calcaneum• Nerve -Tibial nerve• Action – Plantar flexes

foot; flexes leg

(Superficial) Posterior compartment

Soleus• Origin – Shafts of tibia and

fibula• Insertion – Achilles tendon

into calcaneum• Nerve -Tibial nerve• Action – Plantar flexor of

foot• blood supply

Peroneal artery proximally and the posterior tibial artery distally

Deep Posterior Compartment

Blood supply: The posterior tibial artery

Innervation:Tibial nerve.

Deep Posterior Compartment

Muscles:• Popliteus• Flexor digitorum longus• Flexor hallucis longus• Tibialis posterior

Deep Posterior Compartment• Popliteus– Origin - lateral

condyle of femur and lateral meniscus– Insertion – proximal

shaft of tibia– Nerve -Tibial nerve– Action – flex and

medially rotate leg

Deep Posterior Compartment• Flexor digitorum longus– Origin - shaft of tibia– Insertion - distal

phalanges of toe 2-5 – Nerve -Tibial nerve– Action – plantarflex

and invert foot, flex toe

Deep Posterior Compartment• Flexor hallucis longus– Origin - shaft of

fibula– Insertion - base of

distal phalanx of big toe.

– Nerve -Tibial nerve– Action - plantarflex

and invert foot, flex toe

Deep Posterior Compartment• Tibialis posterior

– Origin – shafts of tibia and fibula & interosseous membrane

– Insertion - Major tendon insertion passes to tuberosity of navicular. Posterior tendon slips pass to calcaneus, plantar surface of all 3 cuneforms, cuboid and to base of 2nd, 3rd, and 4th metatarsals.

-- Nerve -Tibial nerve– Action - plantarflex and invert

foot

Pop:popliteus

TP:tibialis post.

PL:peroneus longus

FD:flex. dig. long.

PB:peroneus brevis

FHL:flex. hall. long.

THANK YOU