Dr. SREEKANTH THOTA
WINDSOR UNIVERSITY
SCHOOL OF MEDICINE
DEPARTMENT OF ANATOMY
Lower limbLEG
The leg is that part of the lower limb between the knee joint and ankle joint .
The leg is divided into anterior , posterior , and lateral (fibular) compartments by:
1. An interosseous membrane, which links adjacent borders of the tibia and fibula along most of their length.
2. Two intermuscular septa, which pass between the fibula and deep fascia surrounding the limb.
Fascial Compartments of the Leg
1. Muscles in the anterior compartment of leg dorsiflex the ankle, extend the toes, and invert the foot.
2. Muscles in the posterior compartment plantarflex the ankle, flex the toes, and invert the foot.
3. Muscles in the lateral compartment evert the foot.
Compartments of leg
1. Extensor retinacula :Two extensor retinacula strap the tendons of the extensor muscles to the ankle region and prevent tendon bowing during extension of the foot and toes .
1. Superior extensor retinaculum
2. Inferior extensor retinaculum: Y-shaped
Retinacula of the Ankle
Fibular (peroneal) retinacula bind the tendons of the fibularis longus and fibularis brevis muscles to the lateral side of the foot.
1. Superior fibular retinaculum
2. Inferior fibular retinaculum
Fibular retinacula
It attaches above to the medial malleolus and below and behind to the inferomedial margin of the calcaneus.
Flexor retinaculum
Muscles: The tibialis anterior, extensor digitorum longus, Fibularis tertius, and extensor hallucis longus
Blood supply: Anterior tibial arteryNerve supply: Deep peroneal nerveAction: Dorsiflex the foot at the ankle joint,
extend the toes, and invert the foot.
Anterior compartment of leg
Tibialis anterior Origin: Lateral surface of
shaft of tibia and interosseous membrane
Insertion :Medial cuneiform and base of first metatarsal bone
N. supply: Deep peroneal nerve
Action :Dorsiflexion of foot at ankle joint; inversion of foot.
Extensor digitorum longusOrigin: Anterior surface of
shaft of fibulaInsertion :Extensor
expansion of lateral four toesN. supply: Deep peroneal
nerve
Action :Extension of lateral four toes and dorsiflexion of foot
Extensor hallucis longusOrigin: Anterior surface of
shaft of fibulaInsertion :Base of distal
phalanx of great toeN. supply: Deep peroneal
nerve
Action :Extension of great toe and dorsiflexion of foot
Fibularis tertiusOrigin: Anterior
surface of shaft of fibula
Insertion :Base of fifth metatarsal bone
N. supply: Deep peroneal nerve
Action :Dorsiflexion and eversion of foot
Anterior Tibial Artery: Terminal branch of the popliteal artery.
It arises at the level of the lower border of the popliteus muscle and passes forward into the anterior compartment of the leg through an opening in the upper part of the interosseous membrane.
Artery of the Anterior Compartment of the Leg
Having passed behind the superior extensor retinaculum, it has the tendon of the extensor hallucis longus on its medial side and the deep peroneal nerve and the tendons of extensor digitorum longus on its lateral side.
In front of the ankle joint, the artery becomes the dorsalis pedis artery.
Pulse of anterior tibial artery
Deep Peroneal Nerve: Terminal branch of the common peroneal nerve .
Branches1. Muscular
branches :Tibialis anterior, the extensor digitorum longus, the peroneus tertius, and the extensor hallucis longus.
2. Articular branch to the ankle joint
Nerve Supply of the Anterior Compartment of the Leg
Footdrop and loss of eversion
May cause sensory loss over lateral leg and dorsum of foot
CausesDirect trauma as
nerve passes superficially around neck of fibula
Injury to common fibular nerve
Foot drop
Foot drop, sometimes called drop foot, is a general term for difficulty lifting the front part of the foot.
The loss of dorsiflexion of the ankle causes footdrop.
Muscles: Fibularis longus and Fibularis brevisBlood supply: Branches from the Fibular
arteryNerve supply: Superficial peroneal nerve
Lateral Compartment of the Leg
Fibularis longus Origin: Lateral
surface of shaft of fibula
Insertion :Base of first metatarsal and the medial cuneiform
N. supply: Superficial fibular nerve
Action :Eversion of foot
Fibularis brevis Origin: Lower two-
thirds of lateral surface of shaft of fibula
Insertion :Base of fifth metatarsal bone
N. supply: Superficial Fibular nerve
Action :Eversion of foot
Numerous branches from the fibular artery which lies in the posterior compartment of the leg, pierce the posterior fascial septum and supply the Fibularis muscles.
Artery of the Lateral Compartment of the Leg
Superficial Fibular Nerve: The superficial fibular nerve is one of the terminal branches of the common fibular nerve.
It arises in the substance of the Fibularis longus muscle on the lateral side of the neck of the fibula.
BranchesMuscular branches :
Fibularis longus and brevis
Nerve of the Lateral Compartment of the Leg
Loss of eversion Fibularis longus and brevis
Injury to superficial fibular nerve
Posterior compartment of leg Muscles in the
posterior (flexor) compartment of leg are organized into two groups, superficial and deep.
Blood supply: Posterior tibial artery.
Nerve supply: Tibial nerve
Muscles of the Posterior Compartment of the LegSuperficial group of
muscles1.Gastrocnemius2.Soleus3.Plantaris
Deep group of muscles1.Popliteus2.Tibialis posterior3.Flexor digitorum
longus4.Flexor hallucis
longus
Muscles mainly plantarflex, invert the foot and flex the toes.
Gastrocnemius Soleus Plantaris
Gastrocnemius and plantaris cross knee joint and thus also flex knee .
All three contribute to calcaneal tendon.
Superficial group
Origin: Lateral head from lateral condyle of femur
Medial head from above medial condyle
Insertion:Via tendo calcaneus into posterior surface of calcaneum
Innervation: Tibial nerve Function: Plantarflexes foot
and flexes knee
Gastrocnemius
PlantarisOrigin: Lateral
supracondylar ridge of femur
Insertion: Posterior surface of calcaneum
Innervation: Tibial nerve
Function: Plantarflexes foot and flexes knee
SoleusOrigin: Shafts of tibia
and fibulaInsertion: Posterior
surface of calcaneumInnervation: Tibial nerve Function: Plantarflexes
the foot
Deep group of muscles
Popliteus
Origin: Lateral surface of lateral condyle of femur
Insertion: Posterior surface of shaft of tibia above soleal line
Innervation: Tibial nerve Function: Flexes leg at knee
joint
“Unlock the knee” popliteus contracts rotating the femur laterally so that flexion of the knee can occur
Flexor digitorum longusOrigin: Posterior surface of
shaft of tibiaInsertion: Bases of distal
phalanges of lateral four toesInnervation: Tibial nerve Function: Flexes distal
phalanges of lateral four toes; plantar flexes foot at ankle joint
Origin: Posterior surface of shaft of fibulaInsertion: Base of distal phalanx of big toeInnervation: Tibial nerve Function: Flexes distal phalanx of big toe;
plantar flexes foot at ankle joint
Flexor hallucis longus
Origin: Posterior surface of shafts of tibia and fibula and interosseous membrane
Insertion: Tuberosity of navicular boneInnervation: Tibial nerve Function: Inversion and plantarflexion of
foot
Tibialis posterior
Tibial nerve:Supplies all muscles in posterior compartment.
Divides into medial and lateral plantar nerves inferior and posterior to medial malleolus.
Nerve supply
Posterior tibial artery:Largest branch of popliteal artery.Divides into medial and lateral plantar
arteries.Fibular artery:Most important branch of posterior tibial artery.Supplies lateral compartment.
Blood supply:
Arteries in the posterior compartment of leg.
Tarsal tunnelThe 'tarsal tunnel' is formed on the
posteromedial side of the ankle by a depression formed by the medial malleolus of the tibia, the medial and posterior surfaces of the talus, the medial surface of the calcaneus and overlying flexor retinaculum.
Contents of Tarsal tunnelStructures That Pass
Behind the Medial Malleolus Beneath the Flexor Retinaculum From Medial to Lateral
1.Tibialis posterior tendon2.Flexor digitorum longus3.Posterior tibial artery4.Tibial nerve5.Flexor hallucis longus( TOM DICK AND HARRY)
Tibial Nerve Entrapment Tarsal tunnel syndrome Tarsal tunnel syndrome is caused
by compression of the tibial nerve in the canal formed by the flexor retinaculum and the foot bones.
Causes: 1. Tenosynovitis (swelling of the
synovial membrane lining the tendons) 2. Fractures of the talus, tibia or
calcaneum bones Symptoms Abnormal sensation such as tingling
and numbness in the sole or toes Treatment non-operative and
operative.
.
Posterior Tibial Pulse
The posterior tibial pulse can usually be palpated between the posterior surface of the medial malleolus and the medial border of the calcaneal tendon.
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